Lincoln Electric Welding System SVM140 A User Manual

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SVM140-A

July, 2005

™

PRO-CUT 55

For use with machine code numbers Below 11000

Safety Depends on You

Lincoln arc welding and cutting

equipment is designed and built

with safety in mind. However,

your overall safety can be

increased by proper installation

. . . and thoughtful operation on

your part. DO NOT INSTALL,

OPERATE OR REPAIR THIS

EQUIPMENT WITHOUT READ-

ING THIS MANUAL AND THE

SAFETY PRECAUTIONS CON-

TAINED THROUGHOUT. And,

most importantly, think before

you act and be careful.

SERVICE MANUAL

• World's Leader in Welding and Cutting Products •

• Sales and Service through Subsidiaries and Distributors Worldwide •

Cleveland, Ohio 44117-1199 U.S.A. TEL: 216.481.8100 FAX: 216.486.1751 WEB SITE: www.lincolnelectric.com

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SAFETY

4.g. Sparks and spatter are thrown from the plasma arc. Wear safe-

PLASMA ARC can injure.

ty glasses, ear protection and oil free protective garments such

as leather gloves, heavy shirt, cuffless trousers, high shoes

and a cap over your hair. Wear ear plugs when cutting or goug-

ing out of position or in confined places. Always wear safety

glasses with side shields when in a cutting or gouging area.

7.a. Keep your body away from nozzle and

plasma arc.

4.h. Connect the work cable to the work as close to the cutting or

gouging area as practical. Work cables connected to the build-

ing framework or other locations away from the cutting or goug-

ing area increase the possibility of the current passing through

lifting chains, crane cables or other alternate circuits. This can

create fire hazards or overheat lifting chains or cables until they

fail.

7.b. Operate the pilot arc with caution. The pilot arc is capable of

burning the operator, others or even piercing safety clothing.

CYLINDER may explode

if damaged.

5.a. Use only compressed gas cylinders contain-

ing the correct gas for the process used and

properly operating regulators designed for the

gas and pressure used. All hoses, fittings, etc.

should be suitable for the application and maintained in good

condition.

ELECTRIC AND MAGNETIC FIELDS

5.b. Always keep cylinders in an upright position securely chained

to an undercarriage or fixed support.

may be dangerous

8.a. Electric current flowing through any conduc-

tor causes localized Electric and Magnetic Fields

(EMF). Cutting or gouging current creates EMF

fields around torch cables and cutting machines.

5.c. Cylinders should be located:

• Away from areas where they may be struck or subjected to

physical damage.

• A safe distance from plasma cutting or gouging, arc weld-

ing operations and any other source of heat, sparks,

or flame.

8.b. EMF fields may interfere with some pace-

makers, so operators having a pacemaker should consult

their physician before cutting or gouging.

5.d. Never allow any part of the electrode, torch or any other elec-

trically “hot” parts to touch a cylinder.

8.c. Exposure to EMF fields during cutting or gouging may have

other health effects which are now not known.

5.e. Keep your head and face away from the cylinder valve outlet

when opening the cylinder valve.

8d. All operators should use the following procedures in order to

minimize exposure to EMF fields from the cutting or gouging

circuit:

5.f. Valve protection caps should always be in place and hand

tight except when the cylinder is in use or connected for use.

8.d.1. Route the torch and work cables together - Secure

them with tape when possible.

5.g. Read and follow the instructions on compressed gas cylin-

ders, associated equipment, and CGA publication P-l,

“Precautions for Safe Handling of Compressed Gases in

Cylinders,”available from the Compressed Gas Association

1235 Jefferson Davis Highway, Arlington, VA 22202.

8.d.2. Never coil the torch cable around your body.

8.d.3. Do not place your body between the torch and

work cables. If the torch cable is on your right side,

the work cable should also be on your right

side.

FOR ELECTRICALLY

powered equipment.

8.d.4. Connect the work cable to the workpiece as close as

possible to the area being cut or gouged.

6.a. Turn off input power using the disconnect

switch at the fuse box before working on the

equipment.

8.d.5. Do not work next to cutting power source.

6.b. Install equipment in accordance with the U.S. National

Electrical Code, all local codes and the manufacturer’s rec-

ommendations.

6.c. Ground the equipment in accordance with the U.S. National

Electrical Code and the manufacturer’s recommendations.

Apr. ‘93

PRO-CUT 55

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iii

NOTES

PRO-CUT 55

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MASTER TABLE OF CONTENTS FOR ALL SECTIONS

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Page

Safety.................................................................................................................................................i-iii

Installation.............................................................................................................................Section A

Operation...............................................................................................................................Section B

Accessories...........................................................................................................................Section C

Maintenance .........................................................................................................................Section D

Theory of Operation .............................................................................................................Section E

Troubleshooting and Repair.................................................................................................Section F

Safety Precautions......................................................................................................................F-2

How to Use Troubleshooting Guide............................................................................................F-2

Troubleshooting Guide................................................................................................................F-4

Test Procedures ........................................................................................................................F-14

Replacement Procedures .........................................................................................................F-50

Electrical Diagrams..............................................................................................................Section G

Parts Manual ....................................................................................................P309 Series & P210-K

PRO-CUT 55

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Section A-1

TABLE OF CONTENTS

- INSTALLATION SECTION -

Installation

Technical Specifications .............................................................................................................A-2

Safety Precautions......................................................................................................................A-4

Select Suitable Location.............................................................................................................A-4

Stacking......................................................................................................................................A-4

Lifting and Moving......................................................................................................................A-4

Tilting ..........................................................................................................................................A-4

High Frequency Interference Protection.....................................................................................A-4

Input Electrical Connections.......................................................................................................A-5

Ground Connection..............................................................................................................A-5

Input Power Cord Connector Installation...................................................................................A-5

Input Wire and Fuse Size .....................................................................................................A-5

Reconnect Procedure...........................................................................................................A-6

Gas Input Connections...............................................................................................................A-7

Output Connections ...................................................................................................................A-8

Torch Connection .................................................................................................................A-8

PRO-CUT 55

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A-2

INSTALLATION

TECHNICAL SPECIFICATIONS - PRO-CUT 55

INPUT RATINGS

Single Phase Input

Voltage and Hertz

Input Currents

Rated Output Amps

208/1/60

230/1/60

460/1/60

208/1/60

230/1/60

460/1/60

Three Phase Input

Voltage and Hertz

Input Currents

Rated Output Amps

208/3/60

230/3/60

460/3/60

208/3/60

230/3/60

460/3/60

IDLE CURRENT AND WATTS

0.42 Amps

230/1/60

98 Watts

RATED OUTPUT

Duty Cycle

50%

Rated Output Amps

100%

OUTPUT

Current Range

Open Circuit Voltage

Pilot Current

25 - 55 Amps

335VDC Maximum

18 Amps @ 100%

Duty Cycle

PRO-CUT 55

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A-3

INSTALLATION

TECHNICAL SPECIFICATIONS (Cont’d) - PRO-CUT 55

GAS REQUIREMENTS

Required Gas Flow Rate

Required Gas Inlet Pressure

70 PSI @ 360 SCHF

(4.8 Bar. @ 10160 LHR)

(6 CFM)

80 to 150 PSI

(5.4 Bar. to 10.2 Bar.)

RECOMMENDED INPUT WIRE AND FUSE SIZES

For all plasma cutting applications based on U.S. National Electrical Code

Ambient Temperature 30°C or Less

AC Input Voltage

Fuse (Super Lag)

Circuit Breaker

(Delay Type)

Type 75°C

Copper Wire in Conduit AWG

(IEC) Sizes

60 Hertz

2 Input Supply Wires

1 Ground Wire

#10 (5.3mm²)

#10 (.3mm²)

230VAC Single Phase

460VAC Single Phase

70 Amps

40 Amps

#8 (8.4mm²)

230VAC Three Phase

460VAC Three Phase

40 Amps

20 Amps

#10 (5.3mm²)

PHYSICAL DIMENSIONS

Height

Width

Depth

Weight with

Torch Cable

12.6 Inches

320 mm

11.0 Inches

280 mm

26.0 Inches

660 mm

70 lbs. (32 kg.)

(25 ft. cable)

85 lbs. (39 kg.)

(50 ft. cable)

PRO-CUT 55

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A-4

INSTALLATION

Read this entire installation section before you

start installation.

LIFTING AND MOVING

WARNING

SAFETY PRECAUTIONS

FALLING EQUIPMENT can cause

injury.

WARNING

• Do not use the pull handle on the

optional undercarriage, if installed,

to lift the machine. This handle is

not designed to support the full

weight of the machine. Using it to

lift the machine could cause per-

sonal injury or damage to the

machine.

ELECTRIC SHOCK can kill.

• Turn the input power OFF at the

disconnect switch or fuse box

and discharge input capacitors

before working inside the equip-

ment.

• Do not touch electrically hot parts or electrodes with

your skin or wet clothing.

• Either the front or rear handles or both may be used

to lift or move the machine.

• Always connect the 55 grounding terminal (located

on the side of the Case Back Assembly) to a good

electrical earth ground.

TILTING

• Always wear dry, insulating gloves.

The Pro-Cut 55 must be placed on a stable, level sur-

face so it will not topple over.

• Turn the 55 Power Switch OFF when connecting

power cord to input power.

HIGH FREQUENCY INTERFERENCE

PROTECTION

Only qualified personnel should install, use, or ser-

vice this equipment.

The Pro-Cut 55 employs a touch start mechanism for

arc initiation. This eliminates high frequency emissions

from the machine as compared with spark gap and

solid state type high frequency generators. Keep in

mind, though, that these machines may be used in an

environment where other high frequency generating

machines are operating. By taking the following steps,

you can minimize high frequency interference.

SELECT SUITABLE LOCATION

Place the Pro-Cut 55 where clean cool air can freely

circulate in through the rear louvers and out through

the front/bottom opening. Dirt, dust or any foreign

material that can be drawn into the machine should be

kept at a minimum. Failure to observe these precau-

tions can result in excessive operating temperatures

and nuisance shutdown of the machine.

• Make sure the power supply chassis is connected to

a good earth ground. The work terminal ground does

NOT ground the machine frame.

• Keep the work ground clamp isolated from other work

clamps that have high frequency.

A source of clean, dry air or nitrogen must be supplied

to the Pro-Cut 55. Oil in the air is a severe problem and

must be avoided. The supply pressure must be

between 80 and 150 psi. The flow rate is approximate-

ly 6.0 cfm (170 l/min.). Failure to observe these pre-

cautions could result in excessive operating tempera-

tures or damage to the torch.

• If the ground clamp cannot be isolated, then keep the

clamp as far as possible from other work clamp con-

nections.

• When the machine is enclosed in a metal building,

several good earth driven electrical grounds around

the periphery of the building are recommended.

Failure to observe these recommended installation

procedures may cause improper function of the Pro-

Cut or possibly even damage the control system or

power supply components.

STACKING

The Pro-Cut 55 cannot be stacked.

PRO-CUT 55

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A-5

INSTALLATION

GROUND CONNECTION

INPUT CONNECTIONS

The frame of the Pro-Cut 55 must be properly ground-

ed. A ground terminal marked with the symbol is

WARNING

mounted on the case bottom directly behind the input

power switch for this purpose. The ground lead of the

input power cord that is attached to the machine must

be connected to this ground terminal. See the

National Electric Code for details on proper grounding

methods. Install in accordance with all local and

national electrical codes.

ELECTRIC SHOCK can kill.

• Have a qualified electrician install and

service this equipment.

• Turn the input power off at the fuse box

before working on this equipment.

• Do not touch electrically hot parts.

INPUT POWER CORD CONNECTOR

INSTALLATION

Before installing the machine, check that input supply

voltage, phase, and frequency are the same as the

machine’s voltage, phase, and frequency as specified

on the machine’s rating plate. See Figure A.1.

The Pro-Cut 55 is supplied with one 11 foot (3.35m) #8

AWG 3 lead input power cord already connected to

the machine. A cord connector provides a strain relief

for the input power cord as it passes through the left

rear access hole. The cord connector is designed for

a cord diameter of .40 - 1.03 in (10.2 - 26.2mm) if it

becomes necessary to install a different input cord.

See Figure A.1.

FIGURE A.1 – RATING PLATE LOCATION

For three phase connection: Replace the input power

cord with a #10 AWG 4 lead cable.

Connect the leads of the cable to a fused power panel.

Make sure the green lead is connected to the panel

and the panel is connected to a good earth ground.

Install in accordance with all local and national electric

codes.

INPUT WIRE AND FUSE SIZE

Fuse the input circuit with the super lag fuses or delay

type circuit breakers recommended on the Technical

Specifications page. Choose an input and grounding

wire size according to local or national codes; also see

the Technical Specifications page. Using fuses or

circuit breakers smaller than recommended may result

in “nuisance” shut-offs from inrush currents, even if

you are not cutting at high currents.

1. CASE BACK

2. RATING PLATE

3. POWER CORD CONNECTOR WITH STRAIN RELIEF

The Pro-Cut 55 should be connected only by a quali-

fied electrician. Installation should be made in accor-

dance with the U.S. National Electrical Code, all local

codes, and the information detailed below.

PRO-CUT 55

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A-6

INSTALLATION

FIGURE A.2 – RECONNECTION DIAGRAM

RECONNECT PROCEDURE

When received directly from the factory, the machines

are internally connected for 230 VAC. Reconnection

will be necessary if a higher input voltage is used. To

reconnect the Pro-Cut to 460 VAC or to connect back

to 230 VAC, follow the directions as outlined below.

Follow this procedure ONLY while the Pro-Cut is dis-

connected from the input power.

RECONNECT PROCEDURE

WARNING

• Disconnect input power before

inspecting or servicing machine.

• Do not operate with wraparound

removed.

• Do not touch electrically live parts.

ELECTRIC

CAUTION

SHOCK

• Only qualified persons should install,

use, or service this equipment.

CAN KILL

Failure to follow these instructions can cause immedi-

ate failure of components in the welder.

1. BE SURE POWER SWITCH IS OFF.

2. CONNECT LEAD 'A' TO DESIRED INPUT VOLTAGE RANGE.

440 - 460V

380 - 415V

1. Open the access door on the back of the machine.

Connection instructions are also included on the

inside of the door.

'A'

220 - 230V

200 - 208V

2. For 230: Position the large switch to 200-230. See

Figure A.2.

3. POSITION SWITCH TO DESIRED INPUT VOLTAGE RANGE.

For 460: Position the large switch to 380-460. See

Figure A-2.

VOLTAGE = 380 - 460V

3. Move the “A” lead to the appropriate terminal.

VOLTAGE = 200 - 230V

PRO-CUT 55

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A-7

INSTALLATION

FIGURE A.3 - COMPRESSED GAS CONNECTION

GAS INPUT CONNECTIONS

Supply the Pro-Cut 55 with clean compressed air or

nitrogen.

• Supply pressure must be between 80 psi and 150

psi.

• Flow rate should be approximately 6.0 cfm (170

I/min.).

NOTE: Oil in the air supply to the Pro-Cut 55 can

cause severe problems. Use only a clean air

supply.

• Connect the gas supply to the Pro-Cut 55’s

pneumatic nipple at the air filter. See Figure A.3.

• Compressed gas should be supplied to the fitting

connection mounted on the filter at the rear of the

machine. If necessary, this fitting can be removed

allowing plumbing access through the 1/4 in.

(6.4mm) NPT input port on the filter body.

WARNING

CYLINDER could explode if damaged.

• Keep cylinder upright and chained to a fixed support.

1. CASE BACK

2. PNEUMATIC NIPPLE

3. AIR FILTER

• Keep cylinder away from areas

where it could be damaged.

4. FLEX TUBE (TO REGULATOR INSIDE MACHINE)

• Never lift machine with cylinder

attached.

• Never allow the cutting torch to

touch the cylinder.

• Keep cylinder away from live elec-

trical parts.

• Maximum inlet pressure 150 psi.

NOTE: When using nitrogen gas from a cylinder, the

cylinder must have a pressure regulator.

• Maximum psi from nitrogen gas cylinder to Pro-Cut

55 regulator should never exceed 150 psi.

• Install a hose between the nitrogen gas cylinder reg-

ulator and the Pro-Cut 55 gas inlet.

PRO-CUT 55

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A-8

INSTALLATION

FIGURE A.4 - TORCH CONNECTION

OUTPUT CONNECTIONS

AT CASE FRONT

TORCH CONNECTION

The Pro-Cut 55 is supplied from the factory with a PCT

80 cutting torch. Additional cutting torches can be

ordered from the K1571 series. Hand-held and mech-

anized torches come with 25 or 50 foot cables.

XXXX XXXX XXXX XXXX

All torches are connected to the Pro-Cut with a quick

connect at the case front for easy change over. See

Figure A-4.

PRO-CUT 55

OFF

For more information on the torch and its components,

refer to the PCT 80 Operators Manual (IM588).

1. TORCH CONNECTION

PRO-CUT 55

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Section B-1

TABLE OF CONTENTS

- OPERATION SECTION -

Operation...............................................................................................................................Section B

Safety Instructions......................................................................................................................B-2

General Description....................................................................................................................B-3

Recommended Process and Equipment....................................................................................B-3

Operational Features and Controls ............................................................................................B-3

Design Features and Advantages...............................................................................................B-3

Cutting Capability .......................................................................................................................B-4

Consumable Life.........................................................................................................................B-4

Limitations...................................................................................................................................B-4

Controls and Settings.................................................................................................................B-5

Pilot Arc Considerations.............................................................................................................B-5

Cutting Operation .......................................................................................................................B-5

User Responsibility.....................................................................................................................B-7

Preheat Temperature for Plasma Cutting ...................................................................................B-7

Procedure Recommendations....................................................................................................B-7

General.................................................................................................................................B-7

Thin Gauge Sheet Metal ......................................................................................................B-7

Thick Sections of Metal........................................................................................................B-8

Suggestions for Extra Utility From the Pro-Cut System......................................................B-8

PRO-CUT 55

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B-2

OPERATION

OPERATING INSTRUCTIONS

Read and understand this entire section of operating

instructions before operating the machine.

SAFETY INSTRUCTIONS

WARNING

ELECTRIC SHOCK can kill.

• Do not touch electrically live parts or

electrodes with your skin or wet cloth-

ing.

• Insulate yourself from the work and ground.

• Always wear dry, insulating gloves.

FUMES AND GASES can be

dangerous.

• Keep your head out of fumes.

• Use ventilation or exhaust to remove fumes from

breathing zone.

CUTTING SPARKS can cause

fire or explosion.

• Keep flammable material away.

• Do not cut containers that have held combustibles.

ARC RAYS can burn.

• Wear eye, ear, and body protection.

PLASMA ARC can injure.

• Keep your body away from nozzle and

plasma arc.

• Operate the pilot arc with caution. The

pilot arc is capable of burning the oper-

ator, others, or even piercing safety

clothing.

Observe additional Safety Guidelines detailed in

the beginning of this manual.

PRO-CUT 55

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B-3

OPERATION

GENERAL DESCRIPTION

DESIGN FEATURES AND

ADVANTAGES

The Pro-Cut 55 is an inverter based constant current,

continuous control plasma cutting power source. It

provides superior and reliable starting characteristics,

cutting visibility and arc stability. When cutting

expanded metal, the Pro-Cut 55 out-performs the

competition due to its quick, clean response to arc

transfers. The power supply design provides high

transfer-to-cut distances, which makes pierce cutting

more reliable with less nozzle wear. The control system

has a safety mechanism to insure that the nozzle and

electrode are in place before cutting or gouging. This

is extremely important due to the high voltages

involved.

The microprocessor controlled Pro-Cut 55 design

makes plasma cutting and gouging tasks uncompli-

cated. This list of design features and advantages will

help you understand the machine's total capabilities

so that you can get maximum use from your machine.

• Light weight and portable design for industrial use.

• Continuous control, 25 - 55 amps.

• Reliable touch start mechanism for plasma arc initi-

ation.

• Unique microprocessor controlled starting

sequence for safe and consistent starting.

The Pro-Cut 55 comes standard with an air regulator,

coarse air filter, and pressure gauge. The machine also

comes with an 11 foot (3.35m) input power cord. There

are four different torch and cable systems to choose

from: hand-held torch with 25 foot (7.62m) or 50 foot

(15.24m) cable, machine and robotic torch both with

25 foot (7.62m) and 50 foot (15.24m) cable.

Consumables are included with each Pro-Cut pur-

chase so that cutting can begin right out of the box.

Consumables can also be ordered as individual pack-

ages. An undercarriage kit can be ordered separately.

• Rapid arc transfer for fast cutting of expanded

metal.

• High transfer distance for ease of use.

• Input overvoltage protection.

• 3.0 second pilot arc.

• Purge momentary push button.

• Air regulator and pressure gauge located on the

front of machine for convenience.

The Pro-Cut 55 initiates the plasma arc with a simple,

yet reliable, touch-start mechanism. This system elim-

inates many of the failure problems associated with hi-

frequency start systems. The Pro-Cut 55 is capable of

cutting with nitrogen or air.

• ”Parts-in-Place” mechanism to detect proper instal-

lation of consumables and torch.

• Automatic detection of faulty output control.

• In-line coarse air filter.

The Pro-Cut 55 is controlled by a microprocessor-

based control board. The machine performs rudimen-

tary self troubleshooting when powered up, which aids

in field servicing.

• Preflow/Postflow timing. Preflow is eliminated if arc

is re-initiated in Postflow.

• Thermostatic Protection.

• Solid state overcurrent protection.

RECOMMENDED PROCESSES AND

EQUIPMENT

• Works with pure nitrogen for cutting nonferrous

materials.

• Reconnectable for 230 VAC or 460 VAC inputs.

• Quick disconnect torch.

The Pro-Cut 55 is capable of all cutting and gouging

applications within its output capacity of 25 to 55

amps. These applications include thin gage sheet

metal and expanded metal.

• Display indicators for machine status.

• Unique electrode and Vortech™ nozzle design for

optimum cooling and long life.

OPERATIONAL FEATURES AND

CONTROLS

• Swirl texture inside Vortech™ nozzle for better start-

ing reliability and higher quality cuts.

• Unique drag cup design for durability and elimina-

tion of double arcing.

The Pro-Cut 55 comes with an ON/OFF POWER

SWITCH, OUTPUT CURRENT CONTROL, PURGE

BUTTON, STATUS INDICATORS and a SAFETY

RESET BUTTON. See Figure B.2 and related discus-

sion.

PRO-CUT 55

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B-4

OPERATION

CUTTING CAPABILITY

The Pro-Cut 55 is rated at 55 amps, at 50% duty cycle

on a 10 minute basis or 40 amps, at 100% duty cycle.

If the duty cycle is exceeded, a thermal protector will

shut off the output of the machine until it cools to the

normal operating temperature.

Figure B.1 shows the cut capacity of the Pro-Cut 55

when cutting mild steel. The graph plots cut thickness

vs. torch travel speed with a torch standoff of 0.15 in.

(3.8mm).

Example: 0.25 material

Amps

Speed (IPM)

FIGURE B.1 – LINCOLN’S PRO-CUT 55 MILD STEEL CUT CAPACITY CHART

100

25 A

45 A

0.625

55 A

0.750

35 A

0.500

0.000

0.125

0.250

Material Thickness

0.375

CONSUMABLE LIFE

LIMITATIONS

The expected life for the Pro-Cut 55's electrode under

normal operating conditions is approximately 320

starts/cuts. An erosion of .060 in. (1.5mm) is typical for

end of electrode life. However, the electrode may last

longer. A green and erratic arc will indicate definite

electrode failure, and the electrode should be

replaced immediately.

Do not exceed output current and duty cycle rating of

machine. Do not use the Pro-Cut 55 for pipe thawing.

It is recommended that consumables be replaced in

complete sets. (Example: Electrode and Nozzle). This

will maximize the performance of the Pro-Cut 55 sys-

tem.

PRO-CUT 55

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B-5

OPERATION

CONTROLS AND SETTINGS

PILOT ARC CONSIDERATIONS

FIGURE B.2 - CASE FRONT CONTROLS

The Pro-Cut has a smooth, continuous pilot arc. The

pilot arc is only a means of transferring the arc to the

workpiece for cutting. Repeated pilot arc starts, in

rapid succession, is not recommended as these starts

will generally reduce consumable life. Occasionally,

the pilot arc may sputter or start intermittently. This is

aggravated when the consumables are worn or the air

pressure is too high. Always keep in mind that the

pilot arc is designed to transfer the arc to the work-

piece and not for numerous starts without cutting.

XXXX XXXX XXXX XXXX

PRO-CUT 55

When the pilot arc is started, a slight impulse will be

felt in the torch handle. This occurrence is normal and

is the mechanism which starts the plasma arc. This

impulse can also be used to help troubleshoot a "no

start" condition.

OFF

1. OUTPUT CURRENT CONTROL KNOB

2. TORCH CONNECTOR

3. WORK CABLE

CUTTING OPERATION

When preparing to cut or gouge, position the machine

as close to the work as possible. Make sure you have

all materials needed to complete the job and have

taken all safety precautions. It is important to follow

these operating steps each time you use the machine.

4. INPUT POWER SWITCH

5. GAS REGULATOR KNOB

6. GAS REGULATOR GAUGE

7. GAS PURGE BUTTON

8. RESET BUTTON

9. STATUS (DISPLAY) BOARD INDICATORS

• Turn the machine's ON/OFF POWER SWITCH to

the OFF position.

1. OUTPUT CURRENT CONTROL KNOB - Adjusts

the amount of cutting current applied. Affects cut-

ting speed, dross formation, cut width, heat zone

and travel speed.

• Connect the air supply to the machine.

• Turn the main power and the machine power switch

on.

2. TORCH CONNECTOR - Quick-connect type cou-

pling for the PCT 80 cutting torch.

- The fan should start.

- The pre-charge circuit will operate for 3 seconds,

then the green "Power" status indicator should

turn on.

3. WORK CABLE - Provides clamp and cable con-

nection to workpiece.

- If the "SAFETY" status indicator is lit, push the

"Reset" button. If there is no problem, the status

indicator will go off. If there is a problem, refer to

"STATUS INDICATOR" in this section.

4. ON/OFF POWER SWITCH - Turns machine on or off.

5. GAS REGULATOR KNOB - Adjusts compressed

gas pressure delivered to the torch. Length of

torch hose is an adjustment factor. Optimum set-

ting is 70-75 psi. The gas purge button must be

pressed in to set pressure.

• Be sure that the work lead is clamped to the work-

piece before cutting.

• Set the output current control knob for maximum

current for high cutting speed and less dross forma-

tion per Figure B.1. Reduce the current, if desired,

to reduce the kerf (cut) width, heat affected zone or

travel speed as required.

6. GAS REGULATOR GAUGE - Provides gas pressure

reading as set by the gas regulator knob.

7. GAS PURGE BUTTON - Used to check or set gas

pressure. Push in and hold to check pressure, then

continue to hold to set the pressure. Shuts off gas

when released.

• Push-in and hold the Purge button to check or set

the gas pressure. Pull the pressure regulator cap out

and turn it to set the pressure.

8. RESET BUTTON - Used to reset the machine fol-

lowing a safety circuit trip.

- Adjust the gas regulator for 70 PSI for 25 foot

(7.62m) torches or 75 PSI for 50 foot (15.24m)

torches.

9. STATUS (DISPLAY) BOARD INDICATORS - Four

lights indicating Power, Gas Low, Thermal and

Safety.

- Release the Purge button.

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B-6

OPERATION

- The gas will immediately turn off. The pressure

5° - 15° Leading Angle

gauge may show an increase in pressure after the

air turns off, but this is normal. Do NOT reset the

pressure while the air is NOT flowing.

• When ready to cut, place the torch near the work,

make certain all safety precautions have been taken

and pull the trigger.

Direction of Travel

- The air will flow for a preflow time of 2 seconds

and the pilot arc will start. (This is true unless the

machine is in postflow, then the preflow time is

skipped and the pilot arc will start immediately.)

- The pilot arc will run for 3 seconds and shut off

unless the arc is brought in contact with the work

and the arc is transferred. Avoid excessive pilot

arc time by transferring the arc to the workpiece

quickly to improve parts life.

10° - 20°

Arc Lag

• Finish the cut to be made and release the trigger.

• When the trigger is released, the arc will stop.

- When the arc is brought within 1/4 in. (6.4mm)

from the workpiece the arc will transfer, the cur-

rent will ramp up to the setting on the control

panel, and the cut can last indefinitely (or until the

duty cycle of the Pro-Cut is exceeded). Do not

touch the nozzle to the work when cutting.

Damage to the consumables may result.

- The gas will continue to flow for 10 seconds of

postflow. If the trigger is activated within this time

period, the pilot arc will immediately restart.

• If the dross is difficult to remove, reduce the cutting

speed. High speed dross is more difficult to remove

than low speed dross.

• The right side of the cut is more square than the left

as viewed along the direction of travel.

• Pierce the workpiece by slowly lowering the torch

onto the metal at a 30° angle away from the opera-

tor. This will blow the dross away from the torch tip.

Slowly rotate the torch to vertical position as the arc

becomes deeper.

• Clean spatter and scale from the nozzle and drag

cup frequently.

• For gouging, tilt the torch about 45° from the work-

piece and hold the nozzle 1/8 in. (3.2mm) to 3/16”

(4.7mm) above the workpiece.

TORCH AT 30⁰ANGLE

TO PIERCE

ANGLE

OF APPROACH

ROTATE TO

90⁰ANGLE TO CUT

30⁰

90⁰

VERTICALL ANGLE

TORCH HELD AT

45⁰ANGLE

FOR CUTTING

THROUGHOUT GOUGE

CUT

ANGLE

MAINTAINED

THROUGHOUT

GOUGE

• Hold the nozzle standoff 1/8 in. (3.2mm) to 3/16 in.

(4.7mm) above the workpiece during cutting. Do not

let the torch nozzle touch the work or carry a long

arc.

• Keep moving while cutting. Cut at a steady speed

without pausing. Maintain the cutting speed so that

the arc lag is 10° to 20° behind the travel direction.

SAFETY STATUS INDICATOR

• If the "SAFETY" status indicators light at any time,

check the following:

•

Use a 5° - 15° leading angle in the direction of the cut.

• Use the drag cup to maintain constant standoff for

better cut quality and to protect the nozzle from

spatter.

- Check the assembly of the torch consumables. If

they are not properly in place, the machine will not

start. Make sure that the shield cup is hand

tight. Do not use pliers or over tighten.

• Use the drag cup with a metal template to prevent

nozzle double arcing.

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B-7

OPERATION

PREHEAT TEMPERATURE FOR

PLASMA CUTTING

WARNING

ELECTRIC SHOCK can kill.

Preheat temperature control is not necessary in most

applications when plasma arc cutting or gouging.

Preheat temperature control may be necessary on

high carbon alloy steels and heat treated aluminum for

crack resistance and hardness control. Job condi-

tions, prevailing codes, alloy level, and other consider-

ations may also require preheat temperature control.

The recommended minimum preheat temperature for

plate thickness up to 1/2 in. (12.7mm) is 70°F (21.1°C).

Higher temperatures may be used as required by the

job conditions and/or prevailing codes. If cracking or

excessive hardness occurs on the cut face, higher pre-

heat temperature may be required.

• Turn off machine at the disconnect

switch on the front of the machine

before tightening, cleaning or replac-

ing consumables.

- Check the conditions of the inside of the nozzle. If

debris has collected, rub the electrode on the

inside bottom of the nozzle to remove any oxide

layer that may have built up. Refer to

“Suggestions for Extra Utility from the Pro-Cut

System.”

Check the condition of the electrode. If the end has

a crater-like appearance, replace it along with the

nozzle. The maximum wear depth of the electrode

is approximately .062 in. (1.6mm). A green and

erratic arc will indicate definite electrode failure.

The electrode should be replaced immediately.

PROCEDURE RECOMMENDATIONS

When properly used, plasma arc cutting or gouging is

a very economical process. Improper use will result in

a very high operating cost.

• Replace the nozzle when the orifice exit is eroded

away or oval shaped.

GENERAL - IN ALL CASES

• After the problem is found, or if there is nothing

apparently wrong, reset the machine by pressing

the "Reset" button. (It is possible for electrical noise

to trip the safety circuit on rare occasions. This

should not be a regular occurrence.)

• Follow safety precautions as printed throughout this

manual and on the machine.

THIN GAUGE SHEET METAL

• If the machine does not reset or continues to trip,

consult the Troubleshooting Section.

Torch Standoff

Machine Output Setting

• Use the proper cutting or gouging procedures

referred to in “Procedure Recommendations”

below.

USER RESPONSIBILITY

Because design, fabrication, erection and cutting vari-

ables affect results, the serviceability of a product or

structure is the responsibility of the user. Variation

such as plate chemistry, plate surface condition (oil,

scale), plate thickness, preheat, quench, gas type, gas

flow rate and equipment may produce results different

from those expected. Some adjustments to proce-

dures may be necessary to compensate for unique

individual conditions. Test all procedures duplicating

actual field conditions.

Output Setting

Min. thru Mid-Range

Min. thru Mid. Range

DRAG thru 1/16"

Standoff

Output set below mid-range.

• The nozzle may be dragged on the metal surface,

touching it lightly to the surface after piercing a hole.

Current control should be set below the mid-range.

• Do not allow cable or body to contact hot surface.

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B-8

OPERATION

1. Occasionally an oxide layer may form over the tip

of the electrode, creating an insulating barrier

between the electrode and nozzle. This will result in

the tripping of the Pro-Cut's safety circuit. When

this happens, turn the power off, remove the noz-

zle and electrode and use the electrode to rub

against the inside bottom surface of the nozzle.

This will help remove any oxide buildup. Replace

the nozzle, turn on the power and continue cutting.

If the Parts-in-Place circuit (safety status indicator

light) continues to trip after cleaning the consum-

ables, replace them with a new set. Do not contin-

ue to cut with excessively worn consumables as

this can cause damage to the torch head and will

degrade cut quality.

THICK SECTIONS OF METAL

Torch Standoff

Machine Output Setting

1/8" thru 3/16"

Standoff

Output Setting

Mid. thru Max. Range

Output set above mid-range.

2. To improve consumable life, here are some sug-

gestions that may be useful:

a. Never drag the nozzle on the work surface if

the output control knob is above the mid-

range setting.

• The best quality and consumable life will be

obtained by holding the torch off the surface about

3/16 in. (4.7mm). Too long an arc may compromise

cut quality and consumable life. The nozzle should

NOT be dragged on the work.

b. Make sure the air supply to the Pro-Cut is

clean and free of oil. Use several extra in-line

filters if necessary.

• Use of the S22151 Drag Cup will maintain the prop-

er standoff. The only time not to use the drag cup

when the output control is set above mid-range is in

special, tight corners. Always hold at least a 1/8 in.

(3.2mm) standoff in those situations.

c. Use the lowest output setting possible to

make a good quality cut at the desired cut

speed.

d. Minimize dross buildup on the nozzle tip by

starting the cut from the edge of the plate

when possible.

• If piercing is required, slowly lower the torch at an

angle of about 30° to blow the dross away from the

torch tip and slowly rotate the torch to a vertical

position as the arc becomes deeper. This process

will blow a lot of molten metal and dross. Be care-

ful! Blow the dross away from the torch, the opera-

tor and any flammable objects.

e. Pierce cutting should be done only when nec-

essary. If piercing, angle the torch about 30°

from the plane perpendicular to the work-

piece, transfer the arc, then bring the torch

perpendicular to the work and begin parallel

movement.

• Where possible, start the cut from the edge of the

workpiece.

f. Reduce the number of pilot arc starts without

transferring to the work.

• Keep moving! A steady speed is necessary. Do not

pause.

g. Reduce the pilot arc time before transferring to

the work.

• Do not allow the torch cable or body to contact a

hot surface.

h. Set air pressure to recommended setting. A

higher or lower pressure will cause turbulence

in the plasma arc, eroding the orifice of the

nozzle tip.

SUGGESTIONS FOR EXTRA UTILITY

FROM THE PRO-CUT SYSTEM

i. Use only Lincoln consumable parts. These

parts are patented. Using any other replace-

ment consumables may cause damage to the

torch or reduce cut quality.

WARNING

ELECTRIC SHOCK can kill.

• Turn off machine at the disconnect

switch on the front of the machine

before tightening, cleaning or replac-

ing consumables.

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Section C-1

TABLE OF CONTENTS

- ACCESSORIES -

Accessories...........................................................................................................................Section C

Options/Accessories...................................................................................................................C-2

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C-2

ACCESSORIES

ALWAYS USE GENUINE LINCOLN ELECTRIC

ELECTRODES AND VORTECH™ NOZZLES

GENERAL OPTIONS /

ACCESSORIES

• Only Genuine Lincoln Electric consumables yield

the best cutting performance for the Pro-Cut 55.

The following options/accessories are available for

your Pro-Cut 55 from your local Lincoln Distributor.

• The patent pending VORTECH™ nozzle provides

an extra “kick” of swirl as the arc exits the nozzle,

which improves cutting performance. No other noz-

zle has this capability or can match its performance.

K1600-1 Undercarriage - A valet style undercarriage

with pull-out handle for machine only. Provides torch

and work cable storage.

S22147-043 - Vortech™ nozzle with an .043” (1.2 mm)

Orifice

S22147-068 - Vortech™ nozzle with an .068” (1.7 mm)

Orifice

S22149 - Electrode - replacement electrodes for cut-

ting.

S22150 - Shield Cup - This shields the torch tip and

provides more visibility to the workpiece than the drag

cup. The shield cup does not prevent the torch tip

from touching the workpiece.

S22151 - Drag Cup - The drag cup protects the torch

by preventing the torch from touching the workpiece.

K1571 Series - PCT 80 Torches come in 25’ and 50’

lengths in either hand held or mechanized versions.

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Section D-1

TABLE OF CONTENTS

-MAINTENANCE-

Maintenance .........................................................................................................................Section D

Safety Precautions......................................................................................................................D-2

Input Filter Capacitor Discharge Procedure...............................................................................D-2

Routine Maintenance..................................................................................................................D-3

Periodic Maintenance.................................................................................................................D-3

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D-2

MAINTENANCE

4. Obtain a high resistance and high wattage resistor

(25-1000 ohms and 25 watts minimum). This resis-

tor is not supplied with machine. NEVER USE A

SHORTING STRAP FOR THIS PROCEDURE.

WARNING

ELECTRIC SHOCK can kill.

5. Locate the two capacitor terminals (large hex head

cap screws) on the top and bottom of the Power

Board shown in Figure D.1.

• Have an electrician install and service

this equipment.

• Turn the input power off at the fuse box

before working on equipment.

6. Use electrically insulated gloves and insulated pli-

ers. Hold the body of the resistor and connect

resistor leads across the two capacitor terminals.

Hold the resistor in place for 10 seconds. DO NOT

TOUCH CAPACITOR TERMINALS WITH YOUR

BARE HANDS.

• Do not touch electrically hot parts.

• Prior to performing preventative maintenance, per-

form the following capacitor discharge procedure to

avoid electric shock.

7. Repeat the discharge procedure for the other

capacitor.

INPUT FILTER CAPACITOR

DISCHARGE PROCEDURE

8. Check voltage across the terminals of all capaci-

tors with a DC voltmeter. Polarity of capacitor ter-

minals is marked on the Power Board above termi-

nals. Voltage should be zero. If any voltage

remains, repeat this capacitor discharge proce-

dure.

1. Turn off input power or disconnect input power

lines.

2. Remove the 5/16 in. hex head screws from the side

and top of the machine and remove wrap-around

machine cover.

3. Be careful not to make contact with the capacitor

terminals that are located on the top and bottom of

the Power Board on the right side of the machine.

FIGURE D.1 — LOCATION OF INPUT FILTER CAPACITOR TERMINALS

POWER

BOARD

UPPER

CAPACITOR TERMINALS

LOWER

CAPACITOR

TERMINALS

POWER

RESISTOR

INSULATED

PLIERS

RIGHT SIDE OF MACHINE

INSULATED

GLOVES

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D-3

MAINTENANCE

ROUTINE MAINTENANCE

PERIODIC MAINTENANCE

1. Keep the cutting or gouging area and the area

around the machine clean and free of combustible

materials. No debris should be allowed to collect

which could obstruct air flow to the machine.

WARNING

ELECTRIC SHOCK can kill.

2. Every 6 months or so, the machine should be

cleaned with a low pressure airstream. Keeping the

machine clean will result in cooler operation and

higher reliability. Be sure to clean these areas (Refer

to Figure D.2):

• Turn off machine at the disconnect

switch on the front of the machine

before tightening, cleaning or replacing

consumables.

- Power, Output and Control printed circuit boards

and heat sinks

Change consumables as required.

- Power Switch

- Main Transformer

- Input Rectifier

1. Thermal Protection

Two thermostats protect the machine from excessive

operating temperatures. Excessive temperatures may

be caused by a lack of cooling air or by operating the

machine beyond the duty cycle and output rating. If

excessive operating temperatures should occur, the

yellow thermal LED will light and the thermostat will

prevent output voltage or current.

3. Examine the sheet metal case for dents or break-

age. Repair the case as required. Keep the case in

good condition to insure that high voltage parts are

protected and correct spacings are maintained. All

external sheet metal screws must be in place to

insure case strength and electrical ground continu-

ity.

Thermostats are self-resetting once the machine cools

sufficiently. If the thermostat shutdown was caused by

excessive output or duty cycle and the fan is operat-

ing normally, the Power Switch may be left on and the

reset should occur within a 15 minute period. If the fan

is not turning or the air intake louvers were obstructed,

then the power must be switched off and the fan prob-

lem or air obstruction must be corrected.

4. Check the air regulator filter to be sure it does not

become clogged. The air filter on the machine is

self draining and will not have to be emptied.

5. Check the filter element every several months to

see if it is clogged (weekly in very dirty environ-

ments). Replace if necessary by first removing the

two screws that attach the filter cage to the back

panel assembly, then slide the cage away from the

back of the machine and remove. Next, twist the

clear filter bowl until it comes off (be careful not to

lose the o-ring seated at the top of the bowl

threads). Unscrew the filter element and replace

with new element. Assemble parts in reverse order

as described above.

2. Filter Capacitor Conditioning (Pro-Cut 55, 400-460

VAC only)

A protection circuit is included to monitor the voltage

across filter capacitors C1 and C2. In the event that

the capacitor voltage is too high, the protection circuit

will prevent output. The protection circuit may prevent

output providing all these circumstances are met:

a. Machine is connected for 400-460 VAC input.

6. Inspect the cable periodically for any slits or punc-

ture marks in the cable jacket. Replace if neces-

sary. Check to make sure that nothing is crushing

the cable and blocking the flow of air through the

air tube inside. Also, check for kinks in the cable

periodically and relieve any so as not to restrict the

flow of air to the torch.

b. Machine did not have power applied for many

months.

c. Machine will not produce output when power is

first switched on.

If these circumstances apply, the proper action is to

switch the machine on and let it idle for up to 30 min-

utes. This is required to condition the filter capacitors

after an extended storage time. The protection circuit

will automatically reset once the capacitor condition-

ing and resultant voltage levels are acceptable. It may

be necessary to turn the power switch off and back on

again after this period.

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D-4

Maintenance

FIGURE D.2 – MAJOR COMPONENT LOCATIONS

1. Case Front

2. Case Back

3. Primary Power Board

4. Output Power Board Assembly

5. Control Board

6. Case Wraparound

7. Machine Base

8. Auxiliary Transformer

9. Main Transformer

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Section E-1

TABLE OF CONTENTS

-THEORY OF OPERATION SECTION-

Theory of Operation .............................................................................................................Section E

General Description ....................................................................................................................E-2

Input Line Voltage, Contactor and Main Transformer.................................................................E-2

Precharge and Protection ...........................................................................................................E-3

Main Transformer ........................................................................................................................E-4

Output Board and Torch .............................................................................................................E-5

Control and Display Boards........................................................................................................E-6

Protection Circuits ......................................................................................................................E-7

Overload Protection..............................................................................................................E-7

Thermal Protection ...............................................................................................................E-7

Insulated Gate Bipolar Transistor (IGBT) Operation ...................................................................E-8

Pulse Width Modulation (PWM)..................................................................................................E-9

FIGURE E.1 – PRO-CUT 55 BLOCK LOGIC DIAGRAM

WORK

NOZZLE

ELECTRODE

POWER BOARD

TORCH

CONNECTOR

MAIN

TRANSFORMER

CR 1

RELAY

OUTPUT BOARD

INPUT

LINE

SWITCH

IGBT

CAPACITOR

IGBT

INPUT

RECTIFIER

CHOKE

PILOT

TRANSISTOR

IGBT

CURRENT

TRANSFORMER

TRIGGER & SAFETY

CAPACITOR

IGBT

AIR

SOLENOID

TRIGGER & SAFETY

AIR

PRESSURE

SWITCH

CR 1

RELAY

DRIVE

SIGNAL

IGBT

"A"

GATE

SIGNALS

ELECTRODE & TRANSFER

CURRENT FEEDBACK

SIGNAL

PILOT ENABLE

CONTROL BOARD

ELECTRODE SOLENOID ENABLE

AIR SOLENOID ENABLE

18/36VAC

THERMOSTATS

FAN

MOTORS

OUTPUT

CONTROL

DISPLAY BOARD

12VAC

24VAC

AUXILIARY

TRANSFORMER

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E-2

THEORY OF OPERATION

FIGURE E.2 – INPUT LINE VOLTAGE

WORK

NOZZLE

ELECTRODE

POWER BOARD

TORCH

CONNECTOR

MAIN

TRANSFORMER

CR 1

RELAY

OUTPUT BOARD

INPUT

LINE

SWITCH

IGBT

INPUT

RECTIFIER

CAPACITOR

CHOKE

PILOT

TRANSISTOR

IGBT

CURRENT

TRANSFORMER

TRIGGER & SAFETY

CAPACITOR

AIR

SOLENOID

IGBT

TRIGGER & SAFETY

AIR

PRESSURE

SWITCH

CR 1

RELAY

DRIVE

SIGNAL

IGBT

"A"

GATE

SIGNALS

ELECTRODE & TRANSFER

CURRENT FEEDBACK

SIGNAL

PILOT ENABLE

CONTROL BOARD

ELECTRODE SOLENOID ENABLE

AIR SOLENOID ENABLE

18/36VAC

THERMOSTATS

FAN

MOTORS

OUTPUT

CONTROL

DISPLAY BOARD

12VAC

24VAC

AUXILIARY

TRANSFORMER

GENERAL DESCRIPTION

INPUT LINE VOLTAGE,

CONTACTOR AND MAIN

TRANSFORMER

The Pro-Cut 55 is a constant current, continuous con-

trol plasma cutting power source. The inverter based

power supply design is controlled by a microprocessor

control board. The control system has a safety mech-

anism to insure that the nozzle and electrode are in

place before cutting or gouging. The Pro-Cut 55 initi-

ates the plasma arc with a simple, yet reliable, touch

start mechanism. This system eliminates many of the

problems associated with hi-frequency type start sys-

tems.

The single-phase or three-phase input power of 200-

230 or 400 to 460 volts AC is connected to the

machine, via an input line cord, to a switch located on

the front panel.

A reconnect panel and voltage range switch allow the

user to configure the machine for either a low or high

input voltage and also connect the auxiliary trans-

former for the appropriate input voltage.

The auxiliary transformer develops the appropriate AC

voltages to operate the cooling fans, the control board

and the plasma output board.

NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.

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E-3

THEORY OF OPERATION

FIGURE E.3 – PRECHARGE AND PROTECTION

WORK

NOZZLE

ELECTRODE

POWER BOARD

TORCH

CONNECTOR

MAIN

TRANSFORMER

CR 1

RELAY

OUTPUT BOARD

INPUT

LINE

SWITCH

IGBT

INPUT

RECTIFIER

CAPACITOR

CHOKE

PILOT

TRANSISTOR

IGBT

CURRENT

TRANSFORMER

TRIGGER & SAFETY

CAPACITOR

AIR

SOLENOID

IGBT

TRIGGER & SAFETY

AIR

PRESSURE

SWITCH

CR 1

RELAY

DRIVE

SIGNAL

IGBT

"A"

GATE

SIGNALS

ELECTRODE & TRANSFER

CURRENT FEEDBACK

SIGNAL

PILOT ENABLE

CONTROL BOARD

ELECTRODE SOLENOID ENABLE

AIR SOLENOID ENABLE

18/36VAC

THERMOSTATS

FAN

MOTORS

OUTPUT

CONTROL

DISPLAY BOARD

12VAC

24VAC

AUXILIARY

TRANSFORMER

PRECHARGE AND PROTECTION

The input voltage is rectified by the input rectifier. The

resultant DC voltage is applied, through the reconnect

switch, to the power board. The power board contains

precharging circuitry for the safe charging of the input

filter capacitors. Once the capacitors are precharged

and balanced the control board activates the CR1

input relay. This connects full input power to the filter

capacitors. When the filter capacitors are fully

charged they act as power supplies for the IGBT

switching circuit. The Insulated Gate Bipolar Tran-

sistors supply the main transformer primary winding

with DC current flow. See IGBT Operation discussion

and diagrams in this section.

The power board also monitors the filter capacitors for

voltage balance and under or overvoltage. If either

should occur, the appropriate signal is sent to the con-

trol board to deactivate the CR1 input relay. The

machine output will also be disabled.

NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.

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E-4

THEORY OF OPERATION

FIGURE E.4 – MAIN TRANSFORMER

WORK

NOZZLE

ELECTRODE

POWER BOARD

TORCH

CONNECTOR

MAIN

TRANSFORMER

CR 1

RELAY

OUTPUT BOARD

INPUT

LINE

SWITCH

IGBT

INPUT

RECTIFIER

CAPACITOR

CHOKE

PILOT

TRANSISTOR

IGBT

CURRENT

TRANSFORMER

TRIGGER & SAFETY

CAPACITOR

AIR

SOLENOID

IGBT

TRIGGER & SAFETY

AIR

PRESSURE

SWITCH

CR 1

RELAY

DRIVE

SIGNAL

IGBT

"A"

GATE

SIGNALS

ELECTRODE & TRANSFER

CURRENT FEEDBACK

SIGNAL

PILOT ENABLE

CONTROL BOARD

ELECTRODE SOLENOID ENABLE

AIR SOLENOID ENABLE

18/36VAC

THERMOSTATS

FAN

MOTORS

OUTPUT

CONTROL

DISPLAY BOARD

12VAC

24VAC

AUXILIARY

TRANSFORMER

MAIN TRANSFORMER

Each IGBT pair acts as a switch assembly. Each

assembly feeds a separate, oppositely wound primary

winding of the main transformer. The reverse direction

of current flow through the main transformer primaries

and the offset timing of the IGBT pairs induce an AC

square wave output signal at the secondary of the

main transformer.

The firing of both IGBT pairs occurs during halves of

the 50 microsecond intervals, creating a constant

20KHZ output.

The secondary portion of the main transformer is made

up of two separate windings. One secondary winding

supplies the electrode-to-work voltage. This is the

high current winding, which is capable of supplying

maximum output current during the cutting process.

The DC current flow through each primary winding is

redirected or "clamped" back to each respective filter

capacitor when the IGBTs are turned off. This is need-

ed due to the inductance of the transformer primary

winding.

The other secondary winding supplies the electrode-

to-nozzle voltage for the pilot arc current. The con-

ductor in this winding is smaller since the pilot current

is considerably less than the cutting current. While

one winding is conducting the other winding is at a lim-

ited voltage and aids in the arc transfer to and from the

workpiece.

The primary currents also pass through the current

transformer, which sends a signal to the control board.

If the primary currents are not equal, the control board

compensates by adjusting the IGBT gate signals.

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E-5

THEORY OF OPERATION

FIGURE E.5 – PLASMA OUTPUT BOARD AND TORCH

WORK

NOZZLE

ELECTRODE

POWER BOARD

TORCH

CONNECTOR

MAIN

TRANSFORMER

CR 1

RELAY

OUTPUT BOARD

INPUT

LINE

SWITCH

IGBT

INPUT

RECTIFIER

CAPACITOR

CHOKE

PILOT

TRANSISTOR

IGBT

CURRENT

TRANSFORMER

TRIGGER & SAFETY

CAPACITOR

AIR

SOLENOID

IGBT

TRIGGER & SAFETY

AIR

PRESSURE

SWITCH

CR 1

RELAY

DRIVE

SIGNAL

IGBT

"A"

GATE

SIGNALS

ELECTRODE & TRANSFER

CURRENT FEEDBACK

SIGNAL

PILOT ENABLE

CONTROL BOARD

ELECTRODE SOLENOID ENABLE

AIR SOLENOID ENABLE

18/36VAC

THERMOSTATS

FAN

MOTORS

OUTPUT

CONTROL

DISPLAY BOARD

12VAC

24VAC

AUXILIARY

TRANSFORMER

OUTPUT BOARD AND TORCH

The output board contains an Insulated Gate Bipolar

Transistor (IGBT) which, upon receiving a pilot signal from

the control board, either enables or disables the current in

the pilot winding. The cutting and pilot rectifier diodes are

also incorporated in the output board. There are two

diodes for each of the secondary windings.

A copper nozzle with a patented internal swirl is used to

focus the arc. A small, precise hole in the end of the noz-

zle constricts the arc and increases the current density.

As the air enters the torch head, it is directed between

the electrode and nozzle for maximum electrode cooling.

A portion of the cooling air exits the chamber through

vents in the side of the nozzle. A swirl texture located

inside the bottom of the nozzle increases the plenum air

swirl strength, and improves arc start reliability and parts-

in-place verification.

There are two P.C. board mounted current sensors. One

sensor regulates pilot and cutting current. The other sen-

sor indicates to the control board when and how much

current transfers to the workpiece.

Plasma arc initiation occurs as follows: First, in the idle

state, a spring inside the torch head pushes the piston

and electrode forward to make continuity with the nozzle.

When the trigger is pulled, air flow begins and creates

enough back force on the electrode to overcome the

force of the spring. However, the solenoid valve allows

enough forward force on the piston to maintain continu-

ity between the consumables. After this continuity has

been verified by the Pro-Cut’s parts-in-place circuit, out-

put current is established and regulated. Once the cur-

rent stabilizes, the solenoid valve turns off, removing the

forward force on the piston. The back pressure drives

the piston and electrode away from the nozzle, creating

the plasma arc. The air stream forces the arc out the ori-

fice of the nozzle. This appears as a pilot arc, which can

then be transferred for cutting.

The output board also includes the trigger circuitry, the gas

solenoid driver, the electrode solenoid driver and the torch

parts-in-place circuitry.

The output choke, which is in series with both the pilot cir-

cuit and the cutting circuit, provides current filtering to

enhance arc stability.

The PCT 80 torch uses a patented touch start mechanism

that provides superior starting performance over other

touch start systems. The torch head consists of 3 major

parts: torch body, insulator and piston. The insulator pro-

vides an electrical barrier between the piston and torch

body. The piston provides a path for electrical current to

the electrode. The piston also drives the electrode to the

nozzle for arc initiation. The torch body contains the main

torch components: the trigger, pilot arc, cutting arc, and air

flow systems are included.

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E-6

THEORY OF OPERATION

FIGURE E.6 – CONTROL AND DISPLAY BOARDS

WORK

NOZZLE

ELECTRODE

POWER BOARD

TORCH

CONNECTOR

MAIN

TRANSFORMER

CR 1

RELAY

OUTPUT BOARD

INPUT

LINE

SWITCH

IGBT

INPUT

RECTIFIER

CAPACITOR

CHOKE

PILOT

TRANSISTOR

IGBT

CURRENT

TRANSFORMER

TRIGGER & SAFETY

CAPACITOR

AIR

SOLENOID

IGBT

TRIGGER & SAFETY

AIR

PRESSURE

SWITCH

CR 1

RELAY

DRIVE

SIGNAL

IGBT

"A"

GATE

SIGNALS

ELECTRODE & TRANSFER

CURRENT FEEDBACK

SIGNAL

PILOT ENABLE

CONTROL BOARD

ELECTRODE SOLENOID ENABLE

AIR SOLENOID ENABLE

18/36VAC

THERMOSTATS

FAN

MOTORS

OUTPUT

CONTROL

DISPLAY BOARD

12VAC

24VAC

AUXILIARY

TRANSFORMER

CONTROL AND DISPLAY BOARDS

The control board receives status and analog feed-

back signals from the output board, display board,

power board and various sensors. The processor

interprets these signals, makes decisions and changes

machine mode and output to satisfy the requirements

as defined by the internal software. The control board

regulates the output of the machine by controlling the

IGBT switching times through pulse width modulation

circuitry. See Pulse Width Modulation in this section.

The display board receives commands from the con-

trol board and, via indicator lights, communicates Pro-

Cut 55 status and operating conditions to the user.

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E-7

THEORY OF OPERATION

THERMAL PROTECTION

PROTECTION CIRCUITS

Two thermostats protect the machine from excessive

operating temperatures. One thermostat is located on

the output choke and the other on the power board

IGBT heat sink. Excessive temperatures may be

caused by a lack of cooling air or by operating the

machine beyond the duty cycle and output rating. If

excessive operating temperatures should occur, the

thermal status indicator will light and the thermostat

will prevent output voltage or current.

Protection circuits are designed into the Pro-Cut 55

machine to sense trouble and shut down the machine

before the trouble damages internal machine compo-

nents. Both overload and thermal protection circuits

are included.

OVERLOAD PROTECTION

The Pro-Cut 55 is electrically protected from produc-

ing higher than normal output currents. If the output

current exceeds 50-60 amps, an electronic protection

circuit limits the current to within the capabilities of

the machine.

Thermostats are self-resetting once the machine cools

sufficiently. If the thermostat shutdown was caused

by excessive output or duty cycle and the fans are

operating normally, the power switch may be left on

and the reset should occur within a 15 minute period.

If the fan or fans are not turning or the air intake lou-

vers are obstructed, the input power must be removed

and the fan problem or air obstruction must be cor-

rected.

Another protection circuit monitors the voltage across

the input filter capacitors. If the filter capacitor voltage

is too high, too low or not balanced the protection cir-

cuit may prevent machine output.

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E-8

THEORY OF OPERATION

INSULATED GATE BIPOLAR

TRANSISTOR (IGBT) OPERATION

An IGBT is a type of transistor. IGBTs are semicon-

ductors well suited for high frequency switching and

high current applications.

Drawing B shows the IGBT in an active mode. When

the gate signal, a positive DC voltage relative to the

source, is applied to the gate terminal of the IGBT, it

is capable of conducting current. A voltage supply

connected to the drain terminal will allow the IGBT to

conduct and supply current to circuit components

coupled to the source. Current will flow through the

conducting IGBT to downstream components as long

as the positive gate signal is present. This is similar

to turning ON a light switch.

Drawing A shows an IGBT in a passive mode. There

is no gate signal, zero volts relative to the source, and

therefore, no current flow. The drain terminal of the

IGBT may be connected to a voltage supply; but since

there is no conduction the circuit will not supply cur-

rent to components connected to the source. The cir-

cuit is turned off like a light switch in the OFF position.

FIGURE E.7 – IGBT OPERATION

POSITIVE

VOLTAGE

APPLIED

GATE

SOURCE

n +

BODY REGION

DRAIN DRIFT REGION

n -

n +

p +

BUFFER LAYER

n +

p +

BUFFER LAYER

INJECTING LAYER

DRAIN

B. ACTIVE

A. PASSIVE

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E-9

THEORY OF OPERATION

The positive portion of the signal represents one IGBT

group¹conducting for 1 microsecond. The negative

portion is the other IGBT group¹. The dwell time (off

time) is 48 microseconds (both IGBT groups off).

Since only 2 microseconds of the 50-microsecond

time period is devoted to conducting, the output

power is minimized.

PULSE WIDTH MODULATION

The term PULSE WIDTH MODULATION describes

how much time is devoted to conduction in the posi-

tive and negative portions of the cycle. Changing the

pulse width is known as MODULATION. Pulse Width

Modulation (PWM) is the varying of the pulse width

over the allowed range of a cycle to affect the output

of the machine.

MAXIMUM OUTPUT

By holding the gate signals on for 22 microseconds

each and allowing only 3 microseconds of dwell time

(off time) during the 50-microsecond cycle, the output

is maximized. The darkened area under the top curve

can be compared to the area under the bottom curve.

The more dark area under the curve, the more power

is present.

MINIMUM OUTPUT

By controlling the duration of the gate signal, the IGBT

is turned on and off for different durations during a

cycle. The top drawing below shows the minimum

output signal possible over a 50-microsecond time

period.

An IGBT group consists of two IGBT modules feeding one transformer primary winding.

FIGURE E.8 – TYPICAL IGBT OUTPUTS

sec

MINIMUM OUTPUT

sec

MAXIMUM OUTPUT

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E-10

NOTES

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Section F-1

TABLE OF CONTENTS

TROUBLESHOOTING & REPAIR SECTION

Troubleshooting & Repair Section.................................................................................Section F

How to Use Troubleshooting Guide ......................................................................................F-2

PC Board Troubleshooting Procedures and Replacement ...................................................F-3

Troubleshooting Guide...........................................................................................................F-4

Test Procedures

Troubleshooting Flow Chart ..........................................................................................F-10

Input Filter Capacitor Discharge Procedure..................................................................F-12

Input Rectifier Test ........................................................................................................F-14

Primary Power Board Resistance Test and Capacitor Voltage Test.............................F-18

Output Power Board Resistance Test...........................................................................F-24

Torch Continuity and Solenoid Test ..............................................................................F-28

Air/Gas Solenoid Test....................................................................................................F-32

T2 Auxiliary Transformer Test........................................................................................F-34

Trigger Circuit Test ........................................................................................................F-38

Low Voltage Circuit Test................................................................................................F-44

Replacement Procedures

Control Board Removal and Replacement ...................................................................F-50

Display Board Removal and Replacement ...................................................................F-54

Output Power Board Removal and Replacement.........................................................F-58

Primary Power Board and Filter Capacitor Removal and Replacement ......................F-62

Input Rectifier Bridge Removal and Replacement........................................................F-66

Retest after Repair ........................................................................................................F-69

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F-2

TROUBLESHOOTING & REPAIR

HOW TO USE TROUBLESHOOTING GUIDE

WARNING

Service and repair should be performed by only Lincoln Electric Factory Trained Personnel.

Unauthorized repairs performed on this equipment may result in danger to the technician and machine

operator and will invalidate your factory warranty. For your safety and to avoid Electrical Shock, please

observe all safety notes and precautions detailed throughout this manual.

This Troubleshooting Guide is provided to help

you locate and repair possible machine malfunc-

tions. Simply follow the three-step procedure

listed below.

Step 3. PERFORM COMPONENT TESTS. The

last column, labeled “Recommended Course of

Action” lists the most likely components that may

have failed in your machine. It also specifies the

appropriate test procedure to verify that the sub-

ject component is either good or bad. If there are

a number of possible components, check the

components in the order listed to eliminate one

possibility at a time until you locate the cause of

your problem.

Step 1. LOCATE PROBLEM (SYMPTOM). Look

under the column labeled “PROBLEM (SYMP-

TOMS). This column describes possible symp-

toms that the machine may exhibit. Find the list-

ing that best describes the symptom that the

machine is exhibiting. Symptoms are grouped

into four main categories: Output Problems,

Function Problems, Cutting Problems and LED

Function Problems.

All of the referenced test procedures referred to in

the Troubleshooting Guide are described in detail

at the end of this chapter. Refer to the

Troubleshooting and Repair Table of Contents to

locate each specific Test Procedure. All of the

referred to test points, components, terminal

strips, etc., can be found on the referenced elec-

trical wiring diagrams and schematics. Refer to

the Electrical Diagrams Section Table of Contents

to locate the appropriate diagram.

Step 2. PERFORM EXTERNAL TESTS. The

second column, labeled “POSSIBLE AREAS OF

MISADJUSTMENT(S)”, lists the obvious external

possibilities that may contribute to the machine

symptom. Perform these tests/checks in the

order listed. In general, these tests can be con-

ducted without removing the case wrap-around

cover.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the test/repairs

safely, contact the Lincoln Electric Service Department for electrical troubleshooting assistance before

you proceed. Call 1-888-935-3877.

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F-3

TROUBLESHOOTING & REPAIR

PC BOARD TROUBLESHOOTING PROCEDURES

- Remove the PC board from the static-shielding bag

and place it directly into the equipment. Don’t set the

PC board on or near paper, plastic or cloth which

could have a static charge. If the PC board can’t be

installed immediately, put it back in the static-shield-

ing bag.

WARNING

ELECTRIC SHOCK

can kill.

•

Have an electrician install and

service this equipment. Turn the

input power OFF at the fuse box

before working on equipment. Do

not touch electrically hot parts.

- If the PC board uses protective shorting jumpers,

don’t remove them until installation is complete.

- If you return a PC board to The Lincoln Electric

Company for credit, it must be in the static-shielding

bag. This will prevent further damage and allow prop-

er failure analysis.

CAUTION

Sometimes machine failures appear to be due to PC

board failures. These problems can sometimes be

traced to poor electrical connections. To avoid prob-

lems when troubleshooting and replacing PC boards,

please use the following procedure:

4. Test the machine to determine if the failure

symptom has been corrected by the

replacement PC board.

NOTE: It is desirable to have a spare (known good)

PC board available for PC board troubleshooting.

1. Determine to the best of your technical ability

that the PC board is the most likely component

causing the failure symptom.

NOTE: Allow the machine to heat up so that all

electrical components can reach their operating

temperature.

2. Check for loose connections at the PC board to

assure that the PC board is properly connected.

5. Remove the replacement PC board and

substitute it with the original PC board to

recreate the original problem.

3. If the problem persists, replace the suspect PC

board using standard practices to avoid static

electrical damage and electrical shock. Read

the warning inside the static resistant bag and

perform the following procedures:

a. If the original problem does not reappear by

substituting the original board, then the PC

board was not the problem. Continue to look

for bad connections in the control wiring

harness, junction blocks, and terminal strips.

PC board can be damaged by static electricity.

b. If the original problem is recreated by the

substitution of the original board, then the PC

board was the problem. Reinstall the

replacement PC board and test the machine.

- Remove your body’s static

charge before opening the static-

shielding bag. Wear an anti-static

wrist strap. For safety, use a 1

Meg ohm resistive cord connected

6. Always indicate that this procedure was

followed when warranty reports are to be

submitted.

grounded part of the

equipment frame.

ATTENTION

Static-Sensitive

Devices

Handle only at

Static-Safe

- If you don’t have a wrist strap,

touch an un-painted, grounded,

part of the equipment frame. Keep

touching the frame to prevent

static build-up. Be sure not to

touch any electrically live parts at

the same time.

NOTE: Following this procedure and writing on the

warranty report, “INSTALLED AND SWITCHED PC

BOARDS TO VERIFY PROBLEM,” will help avoid

denial of legitimate PC board warranty claims.

Workstations

- Tools which come in contact with the PC board must

be either conductive, anti-static or static-dissipative.

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F-4

TROUBLESHOOTING & REPAIR

Observe Safety Guidelines

detailed in the beginning of this manual.

TROUBLESHOOTING GUIDE

PROBLEMS

(SYMPTOMS)

POSSIBLE AREAS OF

MISADJUSTMENT(S)

RECOMMENDED

COURSE OF ACTION

OUTPUT PROBLEMS

Major physical or electrical dam- 1. Contact your local authorized 1. Contact the Lincoln Electric

age is evident when the sheet

metal cover(s) are removed.

Lincoln Electric Field Service

Facility for technical assistance.

Service Department, 216-383-

2531 or 1-888-935-3877.

Machine is dead – no output – no 1. Make sure that the input power 1. Check the input power switch

fan – no status indicator lights.

switch is in the “ON” position.

(S1) for proper operation. See

the Wiring Diagram.

2. Check the input voltage at the

machine. Input voltage must 2. Check the leads associated

match the rating plate and the

reconnect panel.

with the power switch (S1) and

the auxiliary transformer (T2) for

loose or faulty connections.

See the Wiring Diagram.

3. Check for blown or missing

fuses in the input lines and the

0.6 amp slow blow reconnect 3. Perform the Auxiliary Trans-

fuse. former Test.

Machine is dead - not output - no 1. Check the input voltage at the 1. Perform

the

Auxiliary

status indicator lights - fans run.

machine. Input voltage must

match the rating plate and the

reconnect panel.

Transformer Test.

2. Perform the Low Voltage

Circuit Test.

3. Perform the Input Rectifier

Test.

4. The control board may be

faulty. Replace.

5. The display board may be

faulty. Replace.

All status indicators remain imme- 1. The microprocessor has experi- 1. The control board may be

diately after power up.

enced a memory fault. Contact

your Local Lincoln Authorized

Field Service Facility.

faulty. Replace.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-

tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call

1-888-935-3877.

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F-5

TROUBLESHOOTING & REPAIR

TROUBLESHOOTING GUIDE

Observe Safety Guidelines

detailed in the beginning of this manual.

PROBLEMS

(SYMPTOMS)

POSSIBLE AREAS OF

MISADJUSTMENT(S)

RECOMMENDED

COURSE OF ACTION

FUNCTION PROBLEMS

All the status lights begin to blink 1. Make sure the Pro-Cut 55 is 1. Perform the Primary Power

within 5 seconds of power up.

reconnected correctly for the

input voltage being applied. Be

sure to remove input power

and wait at least one minute

before changing the position

Board Resistance Test and

Capacitor Voltage Test.

2. Perform the Input Rectifier

Test.

of the input voltage range 3. The control board may be

switch. faulty. Replace.

2. If the machine is connected for 4. The primary power board may

high input voltage, the input

capacitors may need condition-

be faulty. Replace.

ing.

See

Maintenance

Section.

The machine powers up properly, 1. Make sure the torch is connect- 1. Perform the Auxiliary Trans-

but there is no response when the

gun trigger is pulled. Only the

power LED is lit.

ed properly to the Pro-Cut 55

machine.

former Test.

2. Perform the Trigger Circuit

2. Make sure the air supply is con-

nected and operating properly.

Test.

3. Perform the Gas Solenoid

3. Make sure the torch head con-

sumable parts are in place and

in good condition. Replace if

necessary.

Test.

4. Perform the Torch Continuity

and Solenoid Test.

5. The control board may be

faulty. Replace.

6. The output power board may

be faulty. Perform the Output

Board Resistance Test.

When the torch trigger is pulled, air 1. Make sure the torch consum- 1. Perform the Torch Continuity

begins to flow; but no pilot arc is

established.

ables are in place and in good

condition. Replace if neces-

sary.

and Solenoid Test.

2. Perform the Low Voltage

Circuit Test.

2. Make sure the air pressure is

set at 70 psi (448 kPa.) and the

flow rate is at 6 CFM.

3. The output board may be faulty.

Perform the Output Board

Resistance Test.

3. Make sure there are no kinks or

restrictions for air flow in the

torch cable.

4. The control board may be

faulty. Replace.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-

tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call

1-888-935-3877.

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F-6

TROUBLESHOOTING & REPAIR

Observe Safety Guidelines

detailed in the beginning of this manual.

TROUBLESHOOTING GUIDE

PROBLEMS

(SYMPTOMS)

POSSIBLE AREAS OF

MISADJUSTMENT(S)

RECOMMENDED

COURSE OF ACTION

FUNCTION PROBLEMS

The air begins to flow when the 1. Make sure the air pressure is 1. Perform the Torch Continuity

torch trigger is pulled. There is a

very brief pilot arc. (Normal is 3

seconds.) The sequence is repeat-

ed with subsequent trigger pulls.

set at 70 psi (448 kPa.) and the

flow rate is at 6 CFM.

and Solenoid Test.

2. The output board may be faulty.

Replace.

2. Make sure the torch consum-

ables are in place and in good

condition.

3. The control board may be

faulty. Replace.

3. Make sure the air flow is not

restricted.

4. Make sure the air hose and

screen are not clogged.

The cutting arc starts but sputters 1. Make sure the operating proce- 1. Perform the Torch Continuity

badly.

dure is correct for the process.

See the Operation section of

this manual.

and Solenoid Test.

2. The output board may be faulty.

Replace.

2. Make sure the work clamp is

connected tightly to the work-

piece.

3. The control board may be

faulty. Replace.

3. Make sure the torch consum-

ables are in place and in good

condition.

4. Make sure the air supply is not

contaminated with oil or exces-

sive water.

5. Make sure the air pressure is

set at 70 psi (448 kPa.) and the

flow rate is at 6 CFM.

6. Make sure the air hose and

screen are not clogged.

Nuisance safety trips

1. See Safety Status Indicator in 1. The torch may be faulty. Check

the operation section. or replace.

2. Make sure the correct nozzles 2. The control board may be

are being used for the material

faulty. See Torch Continuity

thickness.

See Operation

and Solenoid Test.

Section.

3. Make sure the output control is

set correctly for the process.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-

tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call

1-888-935-3877.

PRO-CUT 55

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F-7

TROUBLESHOOTING & REPAIR

TROUBLESHOOTING GUIDE

Observe Safety Guidelines

detailed in the beginning of this manual.

PROBLEMS

(SYMPTOMS)

POSSIBLE AREAS OF

MISADJUSTMENT(S)

RECOMMENDED

COURSE OF ACTION

CUTTING PROBLEMS

The pilot arc is normal, but the arc 1. Make sure the operating proce- 1. Check the lead connections X2,

will not transfer to the workpiece.

dure is correct for the process.

See the Operation section of

this manual.

X4 and B21 at the output board.

2. Check the output control

potentiometer (R1). Normal

resistance is 10 ohms. Also

check the associated leads for

loose or faulty connections to

the display board. See the

Wiring Diagram.

2. Make sure the work clamp is

connected tightly to the work-

piece.

3. The workpiece must be electri-

cally conductive material.

3. Check leads #216, #218 and

#219 between the display

board and the control board.

Check for loose or faulty con-

nections.

Diagram.

See the Wiring

4. The control board may be

faulty. Replace.

5. The output board may be faulty.

Perform the Output Board

Resistance Test.

6. The display board may be

faulty. Replace.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-

tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call

1-888-935-3877.

PRO-CUT 55

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F-8

TROUBLESHOOTING & REPAIR

Observe Safety Guidelines

detailed in the beginning of this manual.

TROUBLESHOOTING GUIDE

PROBLEMS

POSSIBLE AREAS OF

RECOMMENDED

(SYMPTOMS)

MISADJUSTMENT(S)

COURSE OF ACTION

LED FUNCTION PROBLEMS

The Air Low LED is lit.

1. Make sure there is at least 70 1. The pressure switch (S5) or

psi (448 kPa) of air pressure

connected to the gas connec-

tion at the back of the Pro-Cut

55.

associated leads may be faulty.

See the Wiring Diagram.

2. The control board may be faulty.

Replace.

2. Press the purge button and set

the regulator to 70 psi (448

kPa). Do not reset the air pres-

sure while the air is off (not flow-

ing).

The Safety LED is flashing.

1. Make sure there is a Lincoln 1. Perform the Torch Continuity

PCT 80 torch connected prop-

and Solenoid Test.

erly to the Pro-Cut 55.

2. Check leads “N”, “E”, #364,

and #369 between the torch

receptacle and the output

board. See the Wiring Diagram.

2. Make sure the torch consum-

ables are in place and in good

condition.

3. The output board may be faulty.

Replace.

The Safety LED is lit and ready.

1. Press the reset button. If the 1. The reset button or associated

torch and consumables are

properly installed, the Safety

LED should turn off.

wiring may be faulty. See the

Wiring Diagram.

2. Perform the Torch Continuity

and Solenoid Test.

3. The control board may be faulty.

Replace.

4. If the machine operates normal-

ly with the Safety LED on, the

display board may be faulty.

Replace.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-

tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call

1-888-935-3877.

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F-9

TROUBLESHOOTING & REPAIR

Observe Safety Guidelines

detailed in the beginning of this manual.

TROUBLESHOOTING GUIDE

PROBLEMS

POSSIBLE AREAS OF

RECOMMENDED

(SYMPTOMS)

MISADJUSTMENT(S)

COURSE OF ACTION

LED FUNCTION PROBLEMS

The Thermal LED is lit.

1. One of the machine’s ther- 1. The thermostat may be faulty.

mostats has tripped. Do not

turn the Pro-Cut 55 off. Allow

the machine to cool. The ther-

mostat(s) will reset themselves.

Replace.

2. The control board may be

faulty. Replace.

3. If the machine operates normal-

ly with the Thermal LED lit, the

display board may be faulty.

Replace.

Either the duty cycle has been

exceeded, the fans are not

functioning or the louvers are

blocked.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-

tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call

1-888-935-3877.

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F-10

TROUBLESHOOTING & REPAIR

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F-11

NOTES

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F-12

TROUBLESHOOTING & REPAIR

INPUT FILTER CAPACITOR DISCHARGE PROCEDURE

WARNING

Service and repair should be performed by only Lincoln Electric factory trained person-

nel. Unauthorized repairs performed on this equipment may result in danger to the tech-

nician or machine operator and will invalidate your factory warranty. For your safety and

to avoid electrical shock, please observe all safety notes and precautions detailed

throughout this manual.

If for any reason you do not understand the test procedures or are unable to perform the

test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-

bleshooting assistance before you proceed. Call 1-888-935-3877.

DESCRIPTION

This procedure will drain off any charge stored in the two large capacitors that are part

of the power board assembly. This procedure MUST be performed, as a safety precau-

tion, before conducting any test or repair procedure that requires you to touch internal

components of the machine.

MATERIALS NEEDED

Volt/Ohmmeter (Multimeter)

5/16” Nut driver

Insulated gloves

Insulated pliers

High wattage resistor - 25 to 1000 ohms, 25 watts minimum

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TROUBLESHOOTING & REPAIR

INPUT FILTER CAPACITOR DISCHARGE PROCEDURE (continued)

4. Obtain a high resistance and high wattage

resistor (25-1000 ohms and 25 watts mini-

mum). This resistor is not supplied with

machine. NEVER USE A SHORTING STRAP

FOR THIS PROCEDURE.

WARNING

ELECTRIC SHOCK can kill.

• Have an electrician install and

5. Locate the four capacitor terminals (large

hex head cap screws) shown in Figure F.1.

One pair is at the top and one pair is at the

bottom of the Power Board.

service this equipment.

• Turn the input power off at the

fuse box before working on

equipment.

6. Use electrically insulated gloves and insu-

lated pliers. Hold the body of the resistor

and connect the resistor leads across the

two capacitor terminals. Hold the resistor in

place for 10 seconds. DO NOT TOUCH

CAPACITOR TERMINALS WITH YOUR

BARE HANDS.

• Do not touch electrically hot parts.

• Prior to performing preventative mainte-

nance, perform the following capacitor dis-

charge procedure to avoid electric shock.

DISCHARGE PROCEDURE

7. Repeat the discharge procedure for the

capacitor on the other two terminals.

1. Turn off input power and disconnect input

power lines.

8. Check the voltage across the terminals of

all capacitors with a DC voltmeter. Polarity

of the capacitor terminals is marked on the

PC board above the terminals. Voltage

should be zero. If any voltage remains,

repeat this capacitor discharge procedure.

2. Remove the 5/16" hex head screws from

the wraparound machine cover.

3. Be careful not to make contact with the

capacitor terminals located in the top and

bottom of the Input Power Board.

FIGURE F.1 – LOCATION OF INPUT FILTER CAPACITOR TERMINALS

INPUT

UPPER

POWER

CAPACITOR TERMINALS

BOARD

LOWER

CAPACITOR

TERMINALS

POWER

RESISTOR

INSULATED

PLIERS

RIGHT SIDE OF MACHINE

INSULATED

GLOVES

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F-14

TROUBLESHOOTING & REPAIR

INPUT RECTIFIER TEST

WARNING

Service and repair should be performed by only Lincoln Electric factory trained person-

nel. Unauthorized repairs performed on this equipment may result in danger to the tech-

nician or machine operator and will invalidate your factory warranty. For your safety and

to avoid electrical shock, please observe all safety notes and precautions detailed

throughout this manual.

If for any reason you do not understand the test procedures or are unable to perform the

test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-

bleshooting assistance before you proceed. Call 1-888-935-3877.

DESCRIPTION

This test will help determine if the input rectifier has “shorted” or “open” diodes.

MATERIALS NEEDED

Analog voltmeter/ohmmeter (multimeter)

Phillips head screw driver

Wiring diagram

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TROUBLESHOOTING & REPAIR

INPUT RECTIFIER TEST (continued)

4. With the phillips head screw driver, remove

TEST PROCEDURE

leads #207, 207A and #209 from the rectifi-

er.

1. Remove main input power to the machine.

2. Perform the Input Filter Capacitor

Discharge Procedure detailed earlier in

this section.

5. Use the analog ohmmeter to perform the

tests detailed in Table F.1. See the Wiring

Diagram.

3. Locate the input rectifier (D1) and lead loca-

tions. See Figure F.2.

FIGURE F.2 – INPUT RECTIFIER AND LEADS

#207

#207A

(-)

#209 (+)

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TROUBLESHOOTING & REPAIR

INPUT RECTIFIER TEST (continued)

TABLE F.1 INPUT RECTIFIER TEST POINTS

TEST POINT TERMINALS

ANALOG METER X10 RANGE

+ Probe

- Probe

Acceptable Meter Readings

207

Greater than 1000 ohms

209

Less than 100 ohms

207

Less than 100 ohms

209

Greater than 1000 ohms

6. If the input rectifier does not meet the accept-

able readings outlined in Table F.1, the com-

ponent may be faulty. Replace.

7. If the input rectifier is good, be sure to recon-

nect leads #207, #207A and #209 to the cor-

rect terminals and torque to 31 in.-lbs. Apply

a coating of Essex D-4-8 insulating com-

pound.

NOTE: Before replacing the input rectifier (D1)

check the input power switch (S1) and

perform the Primary Power Board

Resistance Test. Also check for leaky

or faulty filter capacitors.

8. If the input rectifier is faulty, see the Input

Rectifier Bridge Removal & Replacement

procedure. See the Wiring Diagram and

Figure F.2.

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NOTES

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F-18

TROUBLESHOOTING & REPAIR

PRIMARY POWER BOARD RESISTANCE TEST AND

CAPACITOR VOLTAGE TEST

WARNING

Service and repair should be performed by only Lincoln Electric factory trained personnel.

Unauthorized repairs performed on this equipment may result in danger to the technician or

machine operator and will invalidate your factory warranty. For your safety and to avoid elec-

trical shock, please observe all safety notes and precautions detailed throughout this manu-

al.

If for any reason you do not understand the test procedures or are unable to perform the

test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-

bleshooting assistance before you proceed. Call 1-888-935-3877.

DESCRIPTION

This test will determine if the primary power board has any “shorted” or “leaky” power diodes

or Insulated Gate Bipolar Transistors (IGBTs). Also it will help to indicate any “shorted” input

filter capacitors.

MATERIALS NEEDED

Analog voltmeter/ohmmeter (multimeter)

Wiring Diagram

7/16” Wrench

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TROUBLESHOOTING & REPAIR

PRIMARY POWER BOARD RESISTANCE TEST AND

CAPACITOR VOLTAGE TEST (continued)

FIGURE F.3 – PRIMARY POWER BOARD REMOVAL

CAPACITOR (C2)

TERMINALS

207

202

204

201

PRIMARY POWER

BOARD WITH

INPUT FILTER

CAPACITORS

208

203

205

206

CAPACITOR (C1)

TERMINALS

TEST PROCEDURE

1. Remove main input power to the Pro-Cut

55.

4. Carefully remove the main transformer pri-

mary leads #201, #204, #205 and #208

from the power board.

2. Perform the Input Filter Capacitor

Discharge Procedure detailed earlier in

this section.

5. Use the analog ohmmeter to perform the

test outlined in Table F.2.

3. Locate the primary power board and asso-

ciated lead locations. See Figure F.3.

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TROUBLESHOOTING & REPAIR

PRIMARY POWER BOARD RESISTANCE TEST AND

CAPACITOR VOLTAGE TEST (continued)

TABLE F.2

PRIMARY POWER BOARD RESISTANCE TEST POINTS

TEST POINT TERMINALS

ANALOG METER X10 RANGE

+ Probe

- Probe

Acceptable Meter Readings

201

207A

201

Greater than 1000 ohms

Less than 100 ohms

204

207A

204

Greater than 1000 ohms

Less than 100 ohms

202A

204

202A

Greater than 1000 ohms

Less than 100 ohms

202A

201

202A

Greater than 1000 ohms

Less than 100 ohms

205

203A

205

Greater than 1000 ohms

Less than 100 ohms

208

203A

208

Greater than 1000 ohms

Less than 100 ohms

206

208

206

Greater than 1000 ohms

Less than 100 ohms

206

205

206

Greater than 1000 ohms

Less than 100 ohms

6. If the power board does not meet the

acceptable readings outlined in Table F.2,

the board is faulty. Replace. See Power

Board Removal and Replacement

Procedure.

7. If the power board “passes” the resistance

test, the IGBT portion of the board is good.

However, other circuits on the power board

may be faulty. These circuits are NOT readi-

ly tested or serviceable.

NOTE: Complete power board and filter

capacitor replacement is recom-

mended.

8. Reconnect leads #201, #204, #205 and #208

to their appropriate terminals.

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F-21

TROUBLESHOOTING & REPAIR

PRIMARY POWER BOARD RESISTANCE TEST AND

CAPACITOR VOLTAGE TEST (continued)

4. The following tests will be performed with

the input power applied to the Pro-Cut 55.

BE CAREFUL. ALWAYS REMOVE THE

INPUT POWER AND PERFORM THE

INPUT FILTER CAPACITOR DISCHARGE

PROCEDURE BEFORE TOUCHING ANY

MACHINE COMPONENT.

CAPACITOR VOLTAGE TEST

This test will help the technician to determine if

the input filter capacitors are being charged

equally to the correct voltage levels.

NOTE: This test should only be conducted with

the Pro-Cut 55 connected for 400 VAC and

above, and with the appropriate input voltage

applied.

WARNING

ELECTRIC SHOCK can kill.

TEST PROCEDURE

• Have an electrician install and

service this equipment.

1. Remove main input power to the Pro-Cut

55.

• Turn the input power off at the

fuse box before working on

equipment.

2. Perform the Input Filter Capacitor

Discharge Procedure detailed earlier in

this section.

• Do not touch electrically hot parts.

3. Locate and familiarize yourself with the

capacitor test locations on the primary

power board. See Figure F.3.

†

5. Apply the correct input power and turn ON

the Pro-Cut 55.

†

NOTE: This test should only be conducted

with the Pro-Cut 55 reconnect switch

and “A” jumper configured for 400

VAC and above.

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F-22

TROUBLESHOOTING & REPAIR

PRIMARY POWER BOARD RESISTANCE TEST AND

CAPACITOR VOLTAGE TEST (continued)

6. Check for the appropriate voltages outlined

in Table F.3.

7. If the test voltages do not meet the expect-

ed values as listed in Table F.3, the capaci-

tors or other components on the power

board may be faulty. Replace.

NOTE: Voltages may vary with the input line

voltage.

NOTE: If the capacitor voltages are NOT bal-

anced within 20 VDC, the capacitors may need

“conditioning.” See the Maintenance section.

NOTE: If the capacitor voltage is too high

(over 400 VDC) or too low (less than 220

VDC) the control board will deactivate relay

CR1. This will prevent output.

TABLE F.3 - CAPACITOR VOLTAGES

EXPECTED VOLTS

DC AT CAPACITOR

TERMINALS

INPUT APPLIED

460VAC

440VAC

415VAC

380VAC

325VDC

311VDC

293VDC

269VDC

NOTE: If Capacitor C1 is found to be defective, both Capacitors C1 and C2 must be replaced

at the same time. The capacitors must be replaced in matched sets.

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F-23

NOTES

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F-24

TROUBLESHOOTING & REPAIR

OUTPUT POWER BOARD RESISTANCE TEST

WARNING

Service and repair should be performed by only Lincoln Electric factory trained personnel.

Unauthorized repairs performed on this equipment may result in danger to the technician or

machine operator and will invalidate your factory warranty. For your safety and to avoid elec-

trical shock, please observe all safety notes and precautions detailed throughout this manu-

al.

If for any reason you do not understand the test procedures or are unable to perform the

test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-

bleshooting assistance before you proceed. Call 1-888-935-3877.

DESCRIPTION

This test will help the technician determine if the output power board is faulty.

MATERIALS NEEDED

5/16” Nut driver

Analog Volt/ohmmeter

7/16” Wrench

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F-25

TROUBLESHOOTING & REPAIR

OUTPUT POWER BOARD RESISTANCE TEST (continued)

FIGURE F.4 – OUTPUT POWER BOARD LEAD LOCATIONS

B21

(B11)

Test Point

D30

(G3326-2,3)

G3326 - [

]

PRO-CUT 55 OUTPIUT

J33

x40

(B12)

x20

J31

Test

Point

(G3326-1)

(only)

J32

TEST PROCEDURE

1. Remove input power to the Pro-Cut 55

machine.

4. Remove leads X4, X2, B21, X20, X40 and

plugs J33 and J32 from the output power

board. See Figure F.4.

2. Perform the Input Filter Capacitor

Discharge Procedure detailed earlier in this

section.

5. Using the analog ohmmeter, perform the

resistance checks per Table F.4.

3. Remove the torch assembly from the

machine.

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TROUBLESHOOTING & REPAIR

OUTPUT POWER BOARD RESISTANCE TEST (continued)

TABLE F.4 - OUTPUT POWER BOARD RESISTANCE

CIRCUIT OR

COMPONENT(S)

BEING TESTED

TEST POINTS

EXPECTED RESISTANCE

+Probe J33-Pin4

–Probe Terminal B11

Diode A1

and

associated trace

Less than

100 ohms

+Probe Terminal B11

–Probe J33-Pin4

Diode A1

and

associated trace

Greater than

1000 ohms

+Probe J33-Pin4

–Probe Terminal B12

Diode A1

and

associated trace

Less than

100 ohms

+Probe Terminal B12

–Probe J33-Pin4

Diode A1

and

associated trace

Greater than

1000 ohms

or D30

+Probe R5 Test Point

Diode A2

and

associated trace

Less than

100 ohms

–Probe Terminal B1

+Probe Terminal B1

Diode A2

and

Greater than

1000 ohms

–Probe R5 Test Point

associated trace

–Probe D30 Test Point

or D30

+Probe R5 Test Point

Diode A2

and

associated trace

Less than

100 ohms

-Probe Terminal B2

+Probe Terminal B2

Diode A2

and

Greater than

1000 ohms

–Probe R5 Test Point

associated trace

–Probe D30 Test Point

+Probe R5 Test Point

–Probe J32-Pin14

Transistor A2

and

associated trace

Less than

100 ohms

+Probe J32-Pin14

Transistor A2

and

associated trace

Greater than

1000 ohms

–Probe R5 Test Point

–Probe D30 Test Point

6. If any of the resistance checks are not correct, the

output power board is faulty. Replace. See the

Output Power Board Removal and Replacement

Procedure. Note: Use D30 test point for boards

G3326-2,3.

test, the power diode and transistor portion of the

board is good. However, other circuits on the

power board may be faulty. These circuits are NOT

readily tested or serviceable.

8. Reconnect the leads and plugs previously

removed.

7. If the output power board “passes” the resistance

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F-27

NOTES

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F-28

TROUBLESHOOTING & REPAIR

TORCH CONTINUITY AND SOLENOID TEST

WARNING

Service and repair should be performed by only Lincoln Electric factory trained personnel.

Unauthorized repairs performed on this equipment may result in danger to the technician or

machine operator and will invalidate your factory warranty. For your safety and to avoid elec-

trical shock, please observe all safety notes and precautions detailed throughout this manu-

al.

If for any reason you do not understand the test procedures or are unable to perform the

test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-

bleshooting assistance before you proceed. Call 1-888-935-3877.

DESCRIPTION

This procedure will help the technician determine if the torch cable, consumables and elec-

trode solenoid are functioning properly.

MATERIALS NEEDED

5/16” Nut driver

Volt/ohmmeter

12 VDC @ 1 Amp Power Supply

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F-29

TROUBLESHOOTING & REPAIR

TORCH CONTINUITY AND SOLENOID TEST (continued)

FIGURE F.5 - TORCH CONNECTOR - MACHINE END

Electrode is

White Pair

insulated from

Brass Body

Black Pair

Electrode Lead

Connector

Blue Leads

outside

center

Not used

inside

flex tubes

Torch Solenoid

Vent Tube

White & Black Pairs

power

crimp

source

Air Hose

Red Leads

N.O.

Torch Trigger

3. Using the ohmmeter, check the torch resis-

tances per Table F.5.

TEST PROCEDURE

1. Remove input power to the Pro-Cut 55

machine.

NOTE: Take the “Pin” test point measurements

at the machine end of the torch assem-

bly. See Figure F.5.

2. Remove the torch assembly from the

machine.

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TROUBLESHOOTING & REPAIR

TORCH CONTINUITY AND SOLENOID TEST (continued)

TABLE F.5 - TORCH ASSEMBLY RESISTANCES

TEST

POINTS

CIRCUIT(S) BEING

TESTED

EXPECTED

RESISTANCE

TEST

CONDITIONS

Pin 7 to Pin 8

Parallel pilot arc

leads

1.5 ohms maximum

1.0 ohm maximum

100K ohms minimum

1.0 ohm maximum

None

Pin 7 to Torch

Nozzle

One pilot arc lead to

nozzle

Torch consumables

in place

Pin 8 to Torch

Nozzle

One pilot arc lead to

nozzle

Torch consumables

in place

Pin 1 to Pin 9

Pin 2 to Pin 3

Torch trigger circuit

Electrode Solenoid

Torch trigger NOT

pulled (not activated)

Torch trigger pulled

(activated)

45 to 55 ohms

None

Pin 7 to Torch

Electrode at machine

end of torch

Pilot and Electrode

circuit

1.0 ohm maximum

Torch consumables

in place

Pin 8 to Torch

Electrode at machine

end of torch

Pilot and Electrode

circuit

1.0 ohm maximum

Torch consumables

in place

Pin 7 To

Pin 1

Pin 2

Electrical Isolation

of Circuits

Open

(very high)

Torch

Consumables

Removed

Pin 3

Pin 9

Pin 8 To

Pin 1

Pin 2

Electrical Isolation

of Circuits

Open

(very high)

Torch

Consumables

Removed

Pin 3

Pin 9

Pins 1 & 9 to

all other pins

Electrical Isolation

of Torch Trigger

Circuit

Open

(very high)

None

Pins 2 & 3 to

all other pins

Electrical Isolation

of Torch Solenoid

Circuit

Open

(very high)

4. If any of the resistance checks are not cor-

rect, the torch assembly may be faulty.

Repair or replace.

5. Carefully apply the 12 VDC supply to the

electrode solenoid. (positive to Pin 2 and

negative to Pin 3). The electrode solenoid

should activate. Listen for the solenoid

action in the torch handle. If the solenoid

does not activate, it may be faulty. Replace.

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F-31

NOTES

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F-32

TROUBLESHOOTING & REPAIR

AIR/GAS SOLENOID TEST

WARNING

Service and repair should be performed by only Lincoln Electric factory trained personnel.

Unauthorized repairs performed on this equipment may result in danger to the technician or

machine operator and will invalidate your factory warranty. For your safety and to avoid elec-

trical shock, please observe all safety notes and precautions detailed throughout this manu-

al.

If for any reason you do not understand the test procedures or are unable to perform the

test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-

bleshooting assistance before you proceed. Call 1-888-935-3877.

DESCRIPTION

This procedure will help the technician determine if the solenoid is functioning properly.

MATERIALS NEEDED

5/16” Nut driver

12 VDC @ 3 amp supply

Volt/ohmmeter

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F-33

TROUBLESHOOTING & REPAIR

AIR/GAS SOLENOID TEST (continued)

FIGURE F.6 – AIR SOLENOID

AIR SOLENOID

TEST PROCEDURE

1. Remove input power to the machine.

See the Wiring Diagram. If the leads are

good, the solenoid coil may be faulty.

2. Perform the Input Capacitor Discharge

Procedure detailed earlier in this section.

6. Carefully apply the 12 VDC supply to the

solenoid leads at plug J31 (positive to J31

pin-6 lead #366 and negative to J31 pin-5

lead #361).

3. Locate the air solenoid and leads. See Figure

F.6.

4. Carefully remove plug J31 from the output

power board. See Figure F.7.

With proper air pressure applied, the sole-

noid should activate and air should flow.

5. Check the coil resistance of the solenoid at

plug J31 pin-6 to J31 pin-5. Normal resis-

tance is approximately 20 ohms. If the resis-

tance is abnormal, check the continuity (zero

or very low resistance) of leads #366 and

#361 between the solenoid and plug J31.

If the solenoid activates but air does not

flow, check for a restriction in the air line.

7. Install plug J31 back into the output power

board.

FIGURE F.7 – PLUG J31 LOCATION

B21

(B11)

G3326 - [

]

PRO-CUT 55 OUTPIUT

J33

x40

(B12)

x20

J31

Test

Point

J32

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F-34

TROUBLESHOOTING & REPAIR

(T2) AUXILIARY TRANSFORMER TEST

WARNING

Service and repair should be performed by only Lincoln Electric factory trained personnel.

Unauthorized repairs performed on this equipment may result in danger to the technician or

machine operator and will invalidate your factory warranty. For your safety and to avoid elec-

trical shock, please observe all safety notes and precautions detailed throughout this manu-

al.

If for any reason you do not understand the test procedures or are unable to perform the

test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-

bleshooting assistance before you proceed. Call 1-888-935-3877.

DESCRIPTION

The test will determine if the auxiliary transformer is functional when the correct primary volt-

age is applied to the primary winding.

MATERIALS NEEDED

Volt/ohmmeter

Machine wiring diagram

5/16” Nut driver

230 VAC isolated power supply

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F-35

TROUBLESHOOTING & REPAIR

(T2) AUXILIARY TRANSFORMER TEST (continued)

FIGURE F.8 – T2 AUXILIARY TRANSFORMER

PLUG J21

(H5) 6

(H4)

(H3)

(H2)

PLUG J22

1 (H1)

PLUG J22 (6 Cavity)

T2 AUXILIARY

TRANSFORMER

(H5) 8

(H4)

(H3)

(H1)

(H2) 5

PLUG J22 (8 Cavity)

PROCEDURE

1. Remove main input power to the Pro-Cut 55

machine.

5. Carefully apply the 230 VAC isolated supply

to leads H1 (1J22) and H3 (2J22) of the aux-

iliary transformer. These leads are located in

plug J22.

2. Perform the Input Filter Capacitor

Discharge Procedure detailed earlier in this

section.

6. Carefully check for the presence of the fol-

lowing primary and secondary voltages at the

appropriate leads at plugs J21 and J22. See

Figure F.8 and Table F.6..

3. Locate the auxiliary transformer just behind

the input line switch on the lower right side of

the machine.

4. Locate and disconnect plugs J21 and J22

from the wiring harness. Cut any necessary

cable ties. See Figure F.8.

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F-36

TROUBLESHOOTING & REPAIR

(T2) AUXILIARY TRANSFORMER TEST (continued)

TABLE F.6 - J21 AND J22 (6 Pin) VOLTAGES

TEST POINT

H1 (1J22)

TEST POINT

H2 (4J22)

H4 (3J22)

EXPECTED VOLTAGE

200 - 208VAC

380 - 415VAC

440 - 460VAC

12VAC

H1 (1J22)

H5 (6J22)

Brown (8J21)

Red (2J21)

Blue (9J21)

Blue (4J21)

Brown (3J21)

Red (6J21)

White (5J21)

24VAC

18VAC

J21 AND J22 (8 Pin) VOLTAGES

TEST POINT

H1 (1J22)

Brown (8J21)

Red (2J21)

Blue (9J21)

Blue (4J21)

TEST POINT

H2 (5J22)

H4 (7J22)

H5 (8J22)

H6 (4J22)

Brown (3J21)

Red (6J21)

White (5J21)

EXPECTED VOLTAGE

200 - 208VAC

380 - 415VAC

440 - 460VAC

560 - 600VAC

12VAC

24VAC

18VAC

7. If the correct test voltages are present, the

auxiliary transformer is good.

10. When finished with the test, replace plugs

21 and 22 and the case wraparound.

8. If any of the voltages are missing or very low

with the proper primary voltage applied, the

auxiliary transformer may be faulty.

NOTE: There should not be continuity between

the isolated windings. With the input

power removed from the transformer,

check the windings using the table

below.

9. If the auxiliary transformer tests good but it

does not function when connected to the

Pro-Cut 55, check the harness wiring to the

auxiliary transformer.

Diagram.

See the Wiring

TEST POINT

Brown Lead

Red Lead

EXPECTED RESISTANCE

Greater than 100 K ohms

Blue/White Leads

Red Leads

Blue/White Leads

Brown Leads

Red Leads

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NOTES

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F-38

TROUBLESHOOTING & REPAIR

TRIGGER CIRCUIT TEST

WARNING

Service and repair should be performed by only Lincoln Electric factory trained personnel.

Unauthorized repairs performed on this equipment may result in danger to the technician or

machine operator and will invalidate your factory warranty. For your safety and to avoid elec-

trical shock, please observe all safety notes and precautions detailed throughout this manu-

al.

If for any reason you do not understand the test procedures or are unable to perform the

test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-

bleshooting assistance before you proceed. Call 1-888-935-3877.

DESCRIPTION

The procedure will help the technician determine if there is a problem or “fault” in the inter-

nal trigger circuit.

MATERIALS NEEDED

Ohmmeter/voltmeter (multimeter)

5/16” Nut driver

Simplified Trigger Circuit Diagram

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TROUBLESHOOTING & REPAIR

TRIGGER CIRCUIT TEST (continued)

FIGURE F.9 – SIMPLIFIED TRIGGER CIRCUIT DIAGRAM (Later Versions)

OUTPUT BOARD

CONTROL BOARD

+17VDC

+15VDC

TORCH

RECEPTACLE

1J31

(1J38)

TRIGGER SWITCH

IN TORCH HANDLE

2J31

(7J38)

11J3

#344

(#354)

3J32

(3J35)

#312

12J3

14J32

(6J35)

D25

AUX

COM

7. If the correct voltage is present in Step 6,

carefully check for the presence of approxi-

mately 15 VDC from plug J32 pin-3

(lead#344) (positive) to plug J32 pin-14

(lead#312) (negative). See Figure F.10. Also

see Control Board LED Definitions and

related figures. If the correct voltage is not

present, perform the Low Voltage Circuit

Test.

PROCEDURE

1. Remove input power to the Pro-Cut 55

machine.

2. Perform the Input Filter Capacitor

Discharge Procedure detailed earlier in this

section.

3. Locate the torch cable receptacle and leads

#2 and #4. See Figure F.9, the Simplified

Trigger Circuit Diagram. These leads are best

accessed at plug J31 on the output board.

See Figure F.10.

8. If the correct voltage is present in the above

test, carefully pull the torch trigger.

4. Using the ohmmeter, check for continuity

(less than one ohm) from lead #2 to lead #4.

The torch trigger must be pulled and all input

power removed from the machine. If conti-

nuity (less than one ohm) is not read, check

the leads from plug J31 to the torch cable

receptacle. Perform the Torch Continuity

and Solenoid Test.

WARNING

PILOT ARC, CUTTING ARC, AND HIGH VOLT-

AGE MAY BE PRESENT AT THE

TORCH HEAD. Perform this test

with the air input removed to avoid

a pilot arc at the torch.

5. If less than one ohm is read (only when the

torch trigger is pulled), proceed to the next

step.

Also see Output Board LED

Definitions and related figures.

6. Apply the correct input power to the Pro-Cut

55. Carefully check for approximately 17

VDC from plug J31 pin-1(lead#4) (positive) to

plug J31 pin-2 (lead#2) (negative). See

Figure F.10. If the correct voltage is not pre-

sent, perform the Low Voltage Circuit Test.

Also see Output Board LED Definitions and

related figures.

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TROUBLESHOOTING & REPAIR

TRIGGER CIRCUIT TEST (continued)

9. With the torch trigger activated check the

voltage at plug J32 pin-3 (lead#344) (posi-

tive) to plug J32 pin-14 (lead#312) (nega-

tive). Normal is less than 1 VDC. If more

than 1 VDC is indicated, the power output

board may be faulty. Release (deactivate)

the torch trigger and remove input power to

the Pro-Cut 55.

10. Perform the Input Filter Capacitor

Discharge Procedure.

11. Check the continuity of leads #344 and

#312 between the output board and the

control board.

See Figure F.9, the

Simplified Trigger Circuit Diagram, and

Figure F.10.

12. If all of the above checks are OK, the con-

trol board may be faulty. Replace.

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TROUBLESHOOTING & REPAIR

TRIGGER CIRCUIT TEST (continued)

FIGURE F.10 - OUTPUT BOARD TRIGGER CIRCUIT TEST POINTS AND LEDS

G3326 PRO-CUT 55 OUTPUT

G3326-2,3

LED3

LED5

J31

J32

LED6

LED5

LEAD#2

LEAD#4

LEAD#312

LEAD#344

LED4

LED1

D25

J30

LED4

LED3

LED2

LED1

C13

LED2

PRO-CUT 55 OUTPUT BOARD

LED DEFINITIONS

LED4: (Green) This light indicates that the trig-

ger circuit on the output board has been activat-

ed. This LED should be lit when the torch or

remote trigger is closed. This trigger circuit, on

the output board, then sends a signal to the

control board.

LED1: (Red) This light indicates that 24 VAC is

being supplied to the output board from the aux-

iliary transformer. It also shows that the 24 VAC

is being rectified to approximately 28 VDC. This

DC voltage is used for the "parts-in-place"

check for the torch circuit.

LED5: (Green) This light indicates that the elec-

trode solenoid driver circuit is functioning. When

this light is lit, the electrode solenoid should be

activated. The electrode solenoid should be

energized during gas (air) pre-flow time. During

pilot and cutting arc periods, the LED should be

off. When the arc goes out, the machine enters

the post-flow state. Two seconds after the start

of post-flow the electrode solenoid is activated a

few times. The LED should blink to indicate this

activity. The electrode solenoid will then be

energized for the duration of post-flow. (The LED

should be on.)

LED2: (Red) This light indicates that 12 VAC is

being supplied to the output board from the aux-

iliary transformer. It also shows that the 12 VAC

is being rectified to approximately 17 VDC. This

DC voltage is used to power the trigger circuit

and solenoid driver circuits incorporated on the

output board.

LED3: (Green) This light indicates that the air

solenoid driver circuit is functioning. When this

LED is lit, the air solenoid should be activated.

LED6: (Green) Indicates gate drive for pilot

transistor.

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TROUBLESHOOTING & REPAIR

TRIGGER CIRCUIT TEST (continued)

FIGURE F.11 - CONTROL BOARD LEDs

PRO-CUT 55 CONTROL G3328

LED2

LED1

LED3

CONTROL BOARD LED DEFINITIONS

LED1: (Red) This light indicates that 18 VAC is

being supplied to the control board from the

auxiliary transformer. It also shows that the 18

VAC is being rectified and should be regulated to

+15 VDC. This +15 VDC supply is used to power

the circuitry on the control board.

LED2: (Red) This light indicates that the +5.5

VDC is present. This voltage is derived from the

+15 VDC supply. The +5.5 VDC supply is used

to power the circuitry on the control board.

LED3: (Red) This light indicates that 18 VAC is

being supplied to the control board from the

auxiliary transformer. It also shows that the 18

VAC is being rectified and should be regulated to

-15 VDC. This -15 VDC supply is used to power

the circuitry on the control board.

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F-43

NOTES

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F-44

TROUBLESHOOTING & REPAIR

LOW VOLTAGE CIRCUIT TEST

WARNING

Service and repair should be performed by only Lincoln Electric factory trained personnel.

Unauthorized repairs performed on this equipment may result in danger to the technician or

machine operator and will invalidate your factory warranty. For your safety and to avoid elec-

trical shock, please observe all safety notes and precautions detailed throughout this manu-

al.

If for any reason you do not understand the test procedures or are unable to perform the

test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-

bleshooting assistance before you proceed. Call 1-888-935-3877.

DESCRIPTION

These voltage checks will help the technician determine if the correct voltages are being

applied and processed by the various P.C. boards. Some of the voltage verification test

points are not easily accessible. The presence of these voltages can also be confirmed by

LEDs on the various P.C. boards.

MATERIALS NEEDED

5/16” Nut driver

Volt/ohmmeter (multimeter)

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TROUBLESHOOTING & REPAIR

LOW VOLTAGE CIRCUIT TEST (continued)

FIGURE F.12 - LOW VOLTAGE CIRCUIT DIAGRAM

T2 AUXILIARY

TRANSFORMER

TO H1

"C" TERMINAL

INPUT

BROWN

#53

#56

3J30

=17VDC

RECTIFIER

12VAC

24VAC

6J30

PLASMA

OUTPUT

BOARD

RED

#51

#54

1J30

=28VDC

4J30

RECONNECT

LEAD "A"

BLUE

WHITE

BLUE

#61

#62

#64

1J1

=+15VDC

#216

#219

6J2

9J2

15J40

10J40

18VAC

2J1

=-15VDC

4J1

+15VDC

CONTROL BOARD

J21

PROCEDURE

1. Remove input power to the Pro-Cut 55

machine.

5. Check for the presence of 17 VDC on the out-

put board.

2. Using the 5/16" nutdriver remove the case

wraparound cover.

a. LED2 should be lit when 17 VDC is present.

See Figure F.13. See Output Board LED

Definitions and Figure F.12, Low Voltage

Circuit Diagram.

WARNING

b. To verify the presence of 17 VDC, check

from plug J31 Pin-6 to diode D25 (anode).

See Figure F.13. Make certain the volt-

meter probes make good contact with pin-

6 and the diode anode lead.

ELECTRIC SHOCK can kill.

• Do not touch electrically hot parts.

6. Check for the presence of +15 VDC on the

control board.

a. LED1 should be lit when +15 VDC is pre-

sent. See Figure F.13. See Control

Board LED Definitions and Figure F.12,

Low Voltage Circuit Diagram.

3. Apply the correct input power to the machine

and carefully check for the following voltages.

4. Check for the presence of approximately 28

VDC on the output board.

7. Check for the presence of -15 VDC on the con-

trol board.

a. LED1 should be lit when 28 VDC is present.

See Figure F.13. See Output Board LED

Definitions and Figure F.12, Low Voltage

Circuit Diagram.

a. LED3 should be lit when -15 VDC is pre-

sent. See Figure F.13. See Control

Board LED Definitions and Figure F.12,

Low Voltage Circuit Diagram.

b. To verify the presence of 28 VDC, check

across capacitor C13. Make certain the

voltmeter probes make good contact with

the capacitor leads. See Figure F.13.

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TROUBLESHOOTING & REPAIR

8. Check for the presence of +5 VDC on the

control board.

a. LED2 should be lit when +5 VDC is pre-

sent. See Figure F.14. See Control Board

LED Definitions and Figure F.12, Low

Voltage Circuit Diagram.

9. Check for the presence of +15 VDC being

applied to the display board from the control

board. You may have to remove the display

board to check it.

a. +15 VDC should be present at leads

#216(+) to #219(-). See Figure F.15 and

Figure F.12, Low Voltage Circuit

Diagram.

10. If any of the DC supply voltages are incorrect

or missing, make certain the correct AC sup-

ply voltages are being applied to the P.C.

boards. See Figure F.12, Low Voltage

Circuit Diagram and (T2) Auxiliary

Transformer Test.

11. When the test is complete, remove input

power and replace the case wraparound cover.

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F-47

TROUBLESHOOTING & REPAIR

LOW VOLTAGE CIRCUIT TEST (continued)

FIGURE F.13 – OUTBOARD LOW VOLTAGE CIRCUIT TEST POINTS AND LEDs

G3326 PRO-CUT 55 OUTPUT

LED3

J31

LED5

PIN-6

J32

LED1

D25

LED4

J30

C13

LED2

PRO-CUT 55 OUTPUT BOARD

LED DEFINITIONS

LED4: (Green) This light indicates that the trig-

ger circuit on the output board has been acti-

vated. This LED should be lit when the torch or

remote trigger is closed. This trigger circuit, on

the output board, then sends a signal to the

control board.

LED1: (Red) This light indicates that 24 VAC is

being supplied to the output board from the aux-

iliary transformer. It also shows that the 24 VAC

is being rectified to approximately 28 VDC. This

DC voltage is used for the "parts-in-place"

check for the torch circuit.

LED5: (Green) This light indicates that the elec-

trode solenoid driver circuit is functioning. When

this light is lit, the electrode solenoid should be

activated. The electrode solenoid should be

energized during gas (air) pre-flow time. During

pilot and cutting arc periods, the LED should be

off. When the arc goes out, the machine enters

the post-flow state. Two seconds after the start

of post-flow the electrode solenoid is activated a

few times. The LED should blink to indicate this

activity. The electrode solenoid will then be

energized for the duration of post-flow. (The LED

should be on).

LED2: (Red) This light indicates that 12 VAC is

being supplied to the output board from the aux-

iliary transformer. It also shows that the 12 VAC

is being rectified to approximately 17 VDC. This

DC voltage is used to power the trigger circuit

and solenoid driver circuits incorporated on the

output board.

LED3: (Green) This light indicates that the air

solenoid driver circuit is functioning. When this

LED is lit, the air solenoid should be activated.

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TROUBLESHOOTING & REPAIR

LOW VOLTAGE CIRCUIT TEST (continued)

FIGURE F.14 – CONTROL BOARD LEDs

PRO-CUT 55 CONTROL G3328

LED2

LED1

LED3

CONTROL BOARD LED DEFINITIONS

LED2: (Red) This light indicates that the +5.5

VDC is present. This voltage is derived from the

+15 VDC supply. The +5.5 VDC supply is used

to power the circuitry on the control board.

LED1: (Red) This light indicates that 18 VAC is

being supplied to the control board from the

auxiliary transformer. It also shows that the 18

VAC is being rectified and should be regulated to

+15 VDC. This +15 VDC supply is used to power

the circuitry on the control board.

LED3: (Red) This light indicates that 18 VAC is

being supplied to the control board from the

auxiliary transformer. It also shows that the 18

VAC is being rectified and should be regulated to

-15 VDC. This 15 VDC supply is used to power

the circuitry on the control board.

FIGURE F.15 – DISPLAY BOARD TEST POINTS

L10721 DISPLAY BOARD

(REAR VIEW)

J 40

#216

#219

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F-49

NOTES

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F-50

TROUBLESHOOTING & REPAIR

CONTROL BOARD REMOVAL AND REPLACEMENT

WARNING

Service and repair should be performed by only Lincoln Electric factory trained personnel.

Unauthorized repairs performed on this equipment may result in danger to the technician or

machine operator and will invalidate your factory warranty. For your safety and to avoid elec-

trical shock, please observe all safety notes and precautions detailed throughout this manu-

al.

If for any reason you do not understand the test procedures or are unable to perform the

test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-

bleshooting assistance before you proceed. Call 1-888-935-3877.

DESCRIPTION

The following procedure will aid the technician in removing the control board for maintenance

or replacement.

MATERIALS NEEDED

5/16” Nut driver

Needle-nose pliers

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TROUBLESHOOTING & REPAIR

CONTROL BOARD REMOVAL AND REPLACEMENT (continued)

FIGURE F.16 - CASE FRONT SCREW REMOVAL

4 SCREWS

PROCEDURE

1. Remove input power to the Pro-Cut 55

machine.

3. Using the 5/16” nut driver, remove the four

screws holding the front assembly to the top

and base of the machine. See Figure F.16.

2. Remove the wraparound cover and perform

the Input Filter Capacitor Discharge

Procedure detailed earlier in this section.

4. Carefully slide (do not force) the front away

from the rest of the machine about one inch.

This will allow more “working” room to

remove the control board.

FIGURE F.17 - CONTROL BOARD MOLEX PLUG REMOVAL

CONTROL

BOARD

MOLEX PLUGS (5)

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TROUBLESHOOTING & REPAIR

CONTROL BOARD REMOVAL AND REPLACEMENT (continued)

5. Locate the control board and the five molex

6. Carefully remove the five molex type plugs by

depressing the locking tabs and gently

extracting the plugs from the P.C. board

receptacles.

type plugs connected to it. See Figure F.17.

FIGURE F.18 - CONTROL BOARD REMOVAL FROM MOUNTING PINS

DEPRESS

LOCKING TAB ON

MOUNTING PIN

MOUNTING

PIN (8)

CONTROL

BOARD

7. Using the needle-nose pliers and screwdriv-

er, gently remove the control board from the

eight mounting pins by depressing the tabs

on the mounting pins and carefully removing

the board from the pins. See Figure F.18.

9. Replace the five molex type plugs in their

respective receptacles. Be certain they are

securely in place.

10. Carefully reposition the front assembly in

place and install the four mounting screws

previously removed.

CAUTION

11. Inspect, clear and secure all leads before

installing the case wrap-around reassembly.

Be sure to follow the recommended static-free

methods for handling printed circuit boards.

Failure to do so can result in permanent damage

to the equipment.

12. Using the 5/16” nut driver, install the case

wraparound.

8. When replacing the control board, align the

mounting holes with the eight mounting pins

and gently slide the P.C. board onto the

mounting pins until the board “snaps” onto

the pins.

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F-53

NOTES

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F-54

TROUBLESHOOTING & REPAIR

DISPLAY BOARD REMOVAL AND REPLACEMENT

WARNING

Service and repair should be performed by only Lincoln Electric factory trained personnel.

Unauthorized repairs performed on this equipment may result in danger to the technician or

machine operator and will invalidate your factory warranty. For your safety and to avoid elec-

trical shock, please observe all safety notes and precautions detailed throughout this manu-

al.

If for any reason you do not understand the test procedures or are unable to perform the

test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-

bleshooting assistance before you proceed. Call 1-888-935-3877.

DESCRIPTION

The following procedure will aid the technician in removing the display board for maintenance

or replacement.

MATERIALS NEEDED

5/16” Nut driver

Screw driver

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TROUBLESHOOTING & REPAIR

DISPLAY BOARD REMOVAL & REPLACEMENT (continued)

FIGURE F.19 - CASE FRONT SCREW REMOVAL

4 SCREWS

PROCEDURE

1. Remove the input power to the Pro-Cut 55

machine.

4. Carefully slide (do not force) the front away

from the rest of the machine about one inch.

This will allow more “working” room to

remove the display board.

2. Remove the wraparound cover and perform

the Input Filter Capacitor Discharge

Procedure detailed earlier in this section.

3. Using the 5/16” nut driver, remove the four

screws holding the front assembly to the top

and base of the machine. See Figure F.19.

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TROUBLESHOOTING & REPAIR

DISPLAY BOARD REMOVAL & REPLACEMENT (continued)

FIGURE F.20 – DISPLAY BOARD REMOVAL

DISPLAY BOARD

CASE FRONT

5. Locate the display P.C. board and the one

plug connected to it. See Figure F.20.

8. When replacing the display board, carefully

connect the plug into the board. Make cer-

tain the plug is secure and the locking tab is

in place.

6. Gently remove the display P.C. board from

the three mounting pins.

9. Align the display board with the three

mounting pins and slide the display board

into place.

CAUTION

Be sure to follow the recommended static-free

methods for handling printed circuit boards.

Failure to do so can result in permanent damage

to the equipment.

10. Carefully reposition the front assembly in

place and install the four mounting screws

previously removed.

11. Inspect, clear and secure all leads in prepa-

ration for the case wraparound reassembly.

7. Depress the locking tab and remove the plug

connector from the display board.

12. Using the 5/16” nut driver, install the case

wraparound.

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F-57

NOTES

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F-58

TROUBLESHOOTING & REPAIR

OUTPUT POWER BOARD REMOVAL AND REPLACEMENT

WARNING

Service and repair should be performed by only Lincoln Electric factory trained personnel.

Unauthorized repairs performed on this equipment may result in danger to the technician or

machine operator and will invalidate your factory warranty. For your safety and to avoid elec-

trical shock, please observe all safety notes and precautions detailed throughout this manu-

al.

If for any reason you do not understand the test procedures or are unable to perform the

test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-

bleshooting assistance before you proceed. Call 1-888-935-3877.

DESCRIPTION

The following procedure will aid the technician in removing the output power board for main-

tenance or replacement.

MATERIALS NEEDED

5/16” Nut driver

3/16” Allen type wrench

7/16” Wrench

Penetrox A-13 (Lincoln E2529) Electrical Joint Compound

Phillips head screw driver

Torque wrench

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TROUBLESHOOTING & REPAIR

OUTPUT POWER BOARD REMOVAL & REPLACEMENT (continued)

FIGURE F.21 – OUTPUT POWER BOARD REMOVAL

OUTPUT POWER BOARD

PROCEDURE

1. Remove input power to the Pro-Cut 55

machine.

3. Locate the output power P.C. board and

associated lead and plug connections. See

Figures F.21 and F.22.

2. Remove the case wraparound and perform

the Input Capacitor Filter Discharge

Procedure detailed earlier in this section.

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TROUBLESHOOTING & REPAIR

OUTPUT POWER BOARD REMOVAL & REPLACEMENT (continued)

FIGURE F.22 – OUTPUT BOARD LEAD LOCATIONS

G3326 - [1] PRO-CUT 55 OUTPIUT

J33

x40

x20

B21

J31

J32

J30

4. Using the 7/16” wrench, remove leads X4, X2

and B21 from the output power board.

9. Carefully remove the output power board

from the heat sink.

5. Remove all plugs from the output power

board.

CAUTION

6. Remove leads X20 and X40 from the output

power board.

Be sure to follow the recommended static-free

methods for handling printed circuit boards.

Failure to do so can result in permanent damage

to the equipment.

7. Using the phillips head screw driver, remove

the two screws from the lower left and right

corners of the output power board.

8. Using the 3/16” allen head wrench, remove

the four socket screws mounting the output

power board to the heat sink.

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TROUBLESHOOTING & REPAIR

OUTPUT POWER BOARD REMOVAL & REPLACEMENT (continued)

REPLACEMENT PROCEDURE

1. Apply a thin coating of Penetrox A-13

Electrical Joint Compound to the mating sur-

faces of the output power board and the heat

sink. Make sure the surfaces are clean. Do

not allow the compound to get into the

threaded holes or on the screw threads.

CAUTION

Be sure to follow the recommended static-free

methods for handling printed circuit boards.

Failure to do so can result in permanent damage

to the equipment.

2. Mount the output power board to the heat

sink and pre-torque the four socket head

screws to 25 inch-pounds.

3. Finish tightening the four screws to 40-48

inch-pounds.

4. Replace the two phillips head screws previ-

ously removed.

5. Replace leads X20 and X40.

6. Replace all plugs previously removed.

7. Replace leads X4 and X2.

8. Replace lead B21 and torque it to 70 inch-

pounds.

9. Clear and secure all leads and replace the

wraparound cover.

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F-62

TROUBLESHOOTING & REPAIR

PRIMARY POWER BOARD AND FILTER CAPACITOR

REMOVAL AND REPLACEMENT

WARNING

Service and repair should be performed by only Lincoln Electric factory trained personnel.

Unauthorized repairs performed on this equipment may result in danger to the technician or

machine operator and will invalidate your factory warranty. For your safety and to avoid elec-

trical shock, please observe all safety notes and precautions detailed throughout this manu-

al.

If for any reason you do not understand the test procedures or are unable to perform the

test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-

bleshooting assistance before you proceed. Call 1-888-935-3877.

DESCRIPTION

The following procedure will aid the technician in removing the primary power board and fil-

ter capacitors for maintenance or replacement.

MATERIALS NEEDED

5/16” Nut driver

3/16” Allen type wrench

7/16” Wrench

Slot-Head screw driver

Torque wrench

3/8” Wrench

Penetrox A-13 (Lincoln E2529) Electrical Joint Compound

PRO-CUT 55

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F-63

TROUBLESHOOTING & REPAIR

PRIMARY POWER BOARD AND FILTER CAPACITOR

REMOVAL AND REPLACEMENT (continued)

FIGURE F.23 – PRIMARY POWER BOARD REMOVAL

PRIMARY POWER

BOARD WITH

INPUT FILTER

CAPACITORS

REMOVAL PROCEDURE

1. Remove input power from the Pro-Cut 55

machine.

4. Label the leads for reassembly.

5. Remove Plug J10.

2. Remove the case wraparound and perform

the Input Filter Capacitor Discharge

Procedure detailed earlier in this section.

6. Using the 7/16” wrench, remove leads 201,

202A, 203A, 204, 205, 206, 207A, 208 and

209.

3. Locate the primary power board and associ-

ated lead and plug connections. See Figure

F.23.

PRO-CUT 55

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F-64

TROUBLESHOOTING & REPAIR

PRIMARY POWER BOARD AND FILTER CAPACITOR

REMOVAL AND REPLACEMENT (continued)

FIGURE F.24 – POWER BOARD HEATSINK AND CAPACITOR REMOVAL

CAPACITOR

CLAMP

PRIMARY

POWER

P.C. BOARD

7/16"

CAPACITOR

BOLT (4)

3/8" MOUNTING

INSULATOR (2)

SOCKET

HEAD

SCREW (4)

MOUNTING

SCREW (2)

7. Using the slot-head screw driver, remove the

two mounting screws from the left side of the

primary power board. See Figure F.24. Take

note of insulator placement for reassembly.

9. Carefully remove the primary power board

from the heat sink.

CAUTION

8. Using the 3/16” allen type wrench, remove

the four socket head screws and lock wash-

ers mounting the primary power board to the

heat sink.

Be sure to follow the recommended static-free

methods for handling printed circuit boards.

Failure to do so can result in permanent damage

to the equipment.

PRO-CUT 55

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F-65

TROUBLESHOOTING & REPAIR

PRIMARY POWER BOARD AND FILTER CAPACITOR

REMOVAL AND REPLACEMENT (continued)

CAPACITOR REMOVAL

1. Using the 3/8” wrench, remove the four

screws holding the heat sink assembly to the

upper and bottom sections of the machine.

See Figure F.24.

4. Assemble the four socket head screws and

pre-torque them to 25 inch-pounds.

5. Make certain the capacitors are lined up

correctly so that when the capacitor bolts

are assembled through the P.C. board, there

will NOT be any distortion to the P.C. board.

2. Remove the gas hose restraints from the bot-

tom of the heat sink assembly.

3. Remove the two thermostat leads from the

thermostat, which is located next to the

upper capacitor.

6. Finish tightening the four screws to 40-48

inch-pounds.

7. Assemble the two slot head screws with

their appropriate insulators.

4. Carefully remove the heat sink and capacitor

assembly. Clear any necessary leads.

8. Tighten the capacitor clamps.

5. Remove the faulty capacitors by using the

slot head screw driver to loosen the clamps.

Take note of capacitor position in the clamp.

Observe polarity markings and terminal

position.

9. Place the assembly into the machine and

connect the two thermostat leads previous-

ly removed.

10. Secure the assembly to the upper and bot-

tom sections of the unit using the 3/8”

wrench and the four screws previously

removed.

CAPACITOR REPLACEMENT AND

P.C. BOARD REPLACEMENT

11. Connect the J10 plug.

1. Replace the capacitors by positioning them

in the clamps. Do not tighten the clamps.

They must be loose when the P.C. board is

assembled to the capacitors.

12. Connect leads 201, 204, 205, 208 and 209

previously removed.

13. Connect leads 202A, 207A, 206, and 203A

to the capacitor terminals. Torque to 50-60

inch-pounds.

2. Apply a thin coating of Penetrox A-13

Electrical Joint Compound to the mating sur-

faces of the P.C. board and the heat sink and

capacitor terminals.

14. Replace the gas hose restraints previously

removed.

15. Clear and reposition any leads that may be

disturbed.

3. Mount the P.C. board to the heat sink and

capacitor assembly. Make sure the capacitor

terminals line up with the holes in the P.C.

board and with the correct capacitor polari-

ties.

16. Replace the case wraparound cover.

PRO-CUT 55

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F-66

TROUBLESHOOTING & REPAIR

INPUT RECTIFIER BRIDGE REMOVAL AND REPLACEMENT

WARNING

Service and repair should be performed by only Lincoln Electric factory trained personnel.

Unauthorized repairs performed on this equipment may result in danger to the technician or

machine operator and will invalidate your factory warranty. For your safety and to avoid elec-

trical shock, please observe all safety notes and precautions detailed throughout this manu-

al.

If for any reason you do not understand the test procedures or are unable to perform the

test/repairs safely, contact the Lincoln Electric Service Department for electrical trou-

bleshooting assistance before you proceed. Call 1-888-935-3877.

DESCRIPTION

The following procedure will aid the technician in removing the input rectifier bridge for main-

tenance or replacement.

MATERIALS NEEDED

3/16” Allen type wrench

Phillips head screw driver

Torque wrench

Penetrox A13 (Lincoln E2529) Electrical Joint Compound

Essex DC-4-8 (Lincoln E3539) Electrical Insulating Compound

PRO-CUT 55

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F-67

TROUBLESHOOTING & REPAIR

INPUT RECTIFIER BRIDGE REMOVAL AND REPLACEMENT (continued)

5. With the phillips head screw driver, remove

PROCEDURE

the lead terminals connected to the rectifier

1. Remove input power to the Pro-Cut 55.

terminals.

2. Perform the Input Filter Capacitor

6. Using the 3/16” allen wrench, remove the two

Discharge Procedure detailed earlier in this

section.

cap head screws and washers mounting the

input rectifier bridge to the center panel

assembly.

3. Locate the input rectifier and the leads con-

nected to it. See Figure F.25.

4. Identify and mark the leads connected to the

rectifier terminals.

CAP HEAD

MOUNTING

SCREW

#207

#207A

#209

FIGURE F.25 – INPUT RECTIFIER LEAD LOCATIONS

PRO-CUT 55

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F-68

TROUBLESHOOTING & REPAIR

INPUT RECTIFIER BRIDGE REMOVAL AND REPLACEMENT (continued)

7. Carefully remove the input rectifier bridge.

8. When installing a new input rectifier apply a

thin coating of Penetrox A-13 Heat Sink

Compound (Lincoln E2529) to the mating

surfaces. Torque the mounting cap screws

and nuts to 44 in-lbs.

9. Reconnect the 10 leads to the correct ter-

minals and torque the phillips head

screws to 31 in-lbs.

10. Apply Essex DC-4-8 Insulating Com-

pound to all six screw heads and termi-

nals. The heavy input lead terminals

should be against the rectifier terminals.

PRO-CUT 55

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F-69

TROUBLESHOOTING & REPAIR

RETEST AFTER REPAIR

Should a machine under test be rejected for any reason requiring the removal of any mechanical part that could

affect the machine’s electrical characteristics, or if any electrical components are repaired or replaced, the

machine must be retested.

INPUT IDLE AMPS AND WATTS

Input Volts/Hertz

Idle Amps

Idle Watts

230/60

0.42

Output Current Range

25 - 55 Amps

335 Volts

Maximum Open Circuit Voltage

PRO-CUT 55

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F-70

NOTES

PRO-CUT 55

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G-1

ELECTRICAL DIAGRAMS

TABLE OF CONTENTS

ELECTRICAL DIAGRAMS SECTION

Electrical Diagrams Section ..........................................................................................Section G

Wiring Diagram (208V, 230V, 460V) (L10634) ............................................................................G-2

Plasma Output Board Schematic (L10722).................................................................................G-3

Power P.C. Board Schematic (L10616).......................................................................................G-4

Display P.C. Board Assembly (L10721-1)....................................................................................G-5

Display Board (M18920)..............................................................................................................G-6

Control Schematic (G3327) .........................................................................................................G-7

Control P.C. Board Assembly (G3328-1).....................................................................................G-8

Control P.C. Board Assembly (G3328-2).....................................................................................G-9

Output P.C. Board Assembly (G3326-1)....................................................................................G-10

Output P.C. Board Assembly (G3326-2) ....................................................................................G-11

Power P.C. Board Assembly (G3172-1) ....................................................................................G-12

Power P.C. Board Assembly (G3172-2) ....................................................................................G-13

PRO CUT 55

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G-2

ELECTRICAL DIAGRAMS

WIRING DIAGRAM - ENTIRE MACHINE

WIRING DIAGRAM PRO-CUT 55

RIGHT SIDE OF MACHINE

}

INPUT

PER

N.A.

12V

24V

207

207A

1200/450

TP1

POWER

TP3

206

203A

208

209

INPUT

BRIDGE

18V

TP2

J21

205

209

RESET

PSI_SET

RELAY

501

502

503

J22

505

506

507

++VOLT

P_XFMR

AUXILIARY

TRANSFORMER

277B

POWER

277A

223

J10

221

201

204

MAIN

XFMR

404

+15V

216

201

CURRENT

TRANSFORMER

READY LED

LOW_PSI LED

POT WIPER

RESET

205

18V 18V

217

212

218

213

219

214

210

215

207A

202A

507

P_XFMR

503

502

501

506

505

GND

++VOLT

RELAY

1200/450

THERMAL LED

RESET LED

216

217

218

219

212

X20

PSI SET

213

214

215

204

X30

J33

FAN

ELEC

275

276

223

277

221

208

404

401

XFER

TSTAT

X10

210

XFER

365

306

303

302

X40

X20

7,8 ELEC SHUNT (TWIST PR)

360

FAN

MOTORS

J40

B21

275

X40

10K

4,5 XFER SHUNT (TWIST PR)

276

12 GND

366

369

364

365

J31

11 TRIGGER

3 IGBT

312

344

310

309

1,2 TRIGGER

3 NOZZLE

277

277A

CONTROL

360

4 ELECTRODE

5,6 AIR SOL

7,8 ELEC SOL

2,6 PSI SWITCH

10 ELEC SOL

9 AIR SOL

POT

DISPLAY

CW (MAX)

10 WORK

361

J20

CONTROL

302

J32

309

310

344

8 AIR SOL

2 ELEC SOL

3 TRIGGER

PRESSURE

N.C.

306

361

366

WORK

13 IGBT

14 GND

AIR

SOLENOID

0.6A

SLOW BLOW

303

312

S4 PRIMARY

RECONNECT

J30

H3 H3

1,4=24V

200-

208V

400-

220-

230V

369

460VAC

364

12V

OUTPUT

440-

460V

380-

415V

207

206

202A

202

CHOKE

_{x x x}S_{x x}

203

401

202

203A

200-

230VAC

LEFT SIDE OF MACHINE

NOTES:

N.A.

1. FOR MACHINES SUPPLIED WITH INPUT CABLE

FOR SINGLE PHASE INPUT: CONNECT GREEN LEAD TO GROUND PER NATIONAL ELECTRIC CODE.

CONNECT BLACK & WHITE LEADS TO SUPPLY CIRCUIT.

COLOR CODE:

B = BLACK

G = GREEN

R = RED

W = WHITE

U = BLUE

WRAP RED LEAD WITH TAPE TO PROVIDE 600V. INSULATION.

OUTPUT

PC BOARD

BASE

CASE FRONT

FOR THREE PHASE INPUT: CONNECT GREEN LEAD TO GROUND PER NATIONAL ELECTRIC CODE.

CONNECT BLACK, RED & WHITE LEADS TO SUPPLY CIRCUIT.

2. FOR MACHINES NOT SUPPLIED WITH INPUT CABLE

FOR SINGLE PHASE INPUT: GROUND MACHINE PER NATIONAL AND LOCAL ELECTRICAL CODES.

CONNECT TERMINALS U & W TO SUPPLY CIRCUIT.

FOR THREE PHASE INPUT: GROUND MACHINE PER NATIONAL AND LOCAL ELECTRICAL CODES.

CONNECT TERMINALS U, V & W TO SUPPLY CIRCUIT.

J40

PROTECTIVE BONDING CIRCUIT

N = BROWN

Y = YELLOW

J4,J6,

J7,J30

J1,J20

J2,J8,J31

J32

N.B. SINCE COMPONENTS OR CIRCUITRY OF A PRINTED CIRCUIT BOARD MAY CHANGE WITHOUT AFFECTING

THE INTERCHANGEABILITY OF A COMPLETE BOARD, THIS DIAGRAM MAY NOT SHOW THE EXACT

COMPONENTS OR CIRCUITRY HAVING A COMMON CODE NUMBER.

N.C. PLACE "A" LEAD ON APPROPRIATE CONNECTION FOR INPUT VOLTAGE.

CONNECTION SHOWN IS FOR 440-460V OPERATION.

CONNECTOR CAVITY NUMBERING SEQUENCE

(VIEWED FROM COMPONENT SIDE OF BOARD)

ELECTRICAL SYMBOLS PER E1537

L10634 8-7-98A

NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual. The wiring diagram specific to your code is pasted inside one of the enclosure panels of your machine.

PROCUT 55

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G-3

ELECTRICAL DIAGRAMS

SCHEMATIC - PLASMA OUTPUT BOARD

NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.

PROCUT 55

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G-4

ELECTRICAL DIAGRAMS

SCHEMATIC-POWER PC BOARD

NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.

PROCUT 55

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G-5

ELECTRICAL DIAGRAMS

PC BOARD ASSEMBLY-DISPLAY

ITEM

QTY. PART No.

IDENTIFICATION

C1,C2,C3,C4

S16668-4

S13490-25

T12702-27

2700pF/50

4.7/35

OPPOSITE COMPONENT SIDE

CIRCUITRY MULTIPLE

COMPONENT SIDE

CIRCUITRY MULTIPLE

DZ1

1N4740

LED1

M18875-1

LIGHT BAR,LED,YELLOW

LIGHT BAR,LED,RED

LIGHT BAR,LED,YELLOW

LIGHT BAR,LED,GREEN

2N4401

N.B.

LED2,LED7

LED3,LED6

LED4

M18875-5

M18875-2

M18875-6

LED5

M18875-3

LED8

M18875-7

C C C C C C C

LED9

C C C C C C C

LED6

C C C C C C C

LED5

C C C C C C C

^LEDC ³C c

C C C C C C C c C C C C C C C c C C C C C C C c C C C C C C C c

LED9

M18875-4

C C

C C c

C C

C C C

C C c

C C C

Q1,Q2,Q3,Q4

R1,R5,R9,R13

R2,R6,R10,R14

R3,R4,R7,R8,R11,R12

R15,R16

R17

T12704-68

S19400-3321

S19400-6811

S19400-1000

S19400-75R0

S19400-8250

S19400-2671

S19400-2430

C C C C

LED8

C C C C

LED4

C C C C

LED2

C C C C

C C C

C C C C

C C C

LED1

^LED7C

3.32K 1/4W

ARA

J40

6.81K 1/4W

DISPLAY

100 1/4W

L10721-1

75 1/4W

825 1/4W

R18,R19

R20

2.67K 1/4W

243 1/4W

BLANK PART NO. L10721-A

MAKE FROM S19399

(MAKES 24 BOARDS)

NOTE: BLANK SHEARING TOLERANCE SEE P.C. BOARD ASSEMBLY

REQ'D

ITEM

PART NO.

IDENTIFICATION

SEE BLANK

S19365-15

E2861

P.C. BOARD BLANK

RIGHT ANGLE HEADER

SEALANT

3 oz

CAPACITORS = MFD/VOLTS

INDUCTANCE = HENRYS

N.A.

(3 PLACES)

N.C.

4.00

1.10

1.65~.04

MANUFACTURED AS:

L10721-1A0

1.40

LED9

LED8

LED6

LED7

LED5

LED4

LED3

LED2

R20

IDENTIFICATION CODE

1.00

LED1

R14

DZ1

MAKE PER E1911

ENCAPSULATE WITH E1844

TEST PER E3733-D

J40

.20

L10721-1

4.50~.04

4.30

N.C.

N.D.

N.C.

NOTES:

N.A. DO NOT COAT.

N.B. DO NOT COAT VIEWING LENS WITH

ENCAPSULATION MATERIAL.

N.C. COAT WITH ITEM 3 COMPONENT SIDE AFTER ENCAPSULATION.

N.D. HEIGHT OF RTV AND COMPONENTS NOT TO EXCEED .36".

N.F. COAT WITH ITEM 3 ALL TRACES AND SOLDER CONNECTIONS ON

NON-COMPONENT SIDE OF BOARD PRIOR TO ENCAPSUATION.

C A

NOTE: Lincoln Electric assumes no responsibility for liablilities resulting from board level troubleshooting. PC Board repairs will invalidate your factory warranty. Individual Printed Circuit Board Components are not available from Lincoln Electric. This information is pro-

vided for reference only. Lincoln Electric discourages board level troubleshooting and repair since it may compromise the quality of the design and may result in danger to the Machine Operator or Technician. Improper PC board repairs could result in damage to the

machine.

PROCUT 55

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G-6

ELECTRICAL DIAGRAMS

SCHEMATIC - DISPLAY PC BOARD

NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.

PROCUT 55

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G-7

ELECTRICAL DIAGRAMS

SCHEMATIC - CONTROL PC BOARD

NOTE: This diagram is for reference only. It may not be accurate for all machines covered by this manual.

PROCUT 55

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G-8

ELECTRICAL DIAGRAMS

PC BOARD ASSEMBLY-CONTROL (G3328-1)

ITEM

PART NO.

S13490-92

DESCRIPTION

REQ'D

3300/50

.022/50

C2,C8,C10,C13,C14,C17,C20

C23,C24,C29,C31,C34,C35

C36,C37,C39,C40,C41,C47

C53,C55,C58,C63,C64,C65

C66,C68,C69,C73,C74,C75

S16668-5

S13490-121

S13490-63

S13490-71

T11577-52

S13490-93

S16668-11

S13490-25

S13490-42

1000/35

.47/50

C4,C18

100/50

.0047 or .005/1400

27/35

C7,C9

C15,C16,C32,C33,C42

C19,C25,C50

.1/50

4.7/35

C21,C26,C28,C30,C54,C57

C62,C71

1.0/35

C22,C43,C44

S16668-9

150pF/100

C45

S16668-4

2700pF/50

10pF/100

330pF/100

.15/100

C46,C52

S16668-13

S16668-8

C48

C56

S13490-108

S16668-3

C59

100pF/100

.018/50V

1.8/20

C60

S13490-126

S13490-19

S16668-10

T12199-1

C61

C72

4700pF/50

1N4004

D1,D2,D3,D4,D5,D6,D7,D8,D9

PRO-CUT 50 CONTROL

G3328-1

D14,D20,D22,D23,D25

D26,D27

D10,D11,D12,D13

T12705-37

1N5822 SCHOTTKY BARRIER DIODE

C52

C73

D15,D16,D17,D18,D21

T12705-34

T12702-19

S18248-4

1N4936

1N4742A

HEADER

LED2

X11

DZ1,DZ2

X18

X15

S18248-10

S18248-16

S18248-6

C46

R136

R61

S18248-8

X10

C54

LED1,LED2,LED3

T13657-2

RED LED

R184

R183

Q1,Q2,Q3

T12704-68

T12704-80

T12704-69

T13165-16

S19400-2671

S19400-2430

2N4401

C19

HEXFET TRANS. (SS)

C55

C20

R133

R132

1.0 OHM, 5W RESISTOR

2.67K 1/4W

X16

R2,R46,R132

X12

R3,R30,R32,R33,R34,R36,R37

R38,R39

243 1/4W

C44

C45

LED1

LED3

S19400-30R1

S19400-6190

S19400-8251

S19400-3921

S19400-2001

S19400-1001

511 1/4W

30.1 1/4W

619 1/4W

8.25K 1/4W

3.92K 1/4W

2.0K 1/4W

1K 1/4W

R48

C31

R24

C17

R9,R88,R103

R35

DZ2

C33

R10,R42,R95,R96

R11,R12,R13,R14

R17,R26,R27,R49,R51,R59

R61,R62,R63,R68,R69,R81

R84,R93,R94,R104,R106,R108

R134,R138,R139,R152

R153,R154,R156,R158,R160

R164,R165,R166,R178

R179,R180,R181,R182

R18

S19400-5110

S19400-3320

R73

C18

D14

332 1/4W

R119

R51

R18

S19400-1002

10K 1/4W

R166

R165

R167

R19

C50

DZ1

S24073-1

10K,1/2W,TRIMMER

5.11K 1/4W

R17

C42

R19,R47,R53,R55,R57,R85

R149,R157

S19400-5111

R20,R22,R110,R111,R124,R125

R126,R127,R128,R142,R143

R144,R145,R146,R147.R901

R21,R23

S19400-10R0

10 1/4W

R111

S19400-1822

S19400-2210

S19400-3321

18.2K 1/4W

221 1/4W

D20

R110

C32

R24,R35

R28,R112,R115,R116,R117

R118,R119

3.32K 1/4W

R29,R91,R102

S19400-8250

S19400-1004

S19400-7681

S19400-4751

825 1/4W

1M 1/4W

7.68K 1/4W

4.75K

R31

R40,R73,R107

R43,R44,R45,R136,R137,R170

R171,R172

R48,R67,R70,R87,R101

R52,R54,R56

S19400-4752

S19400-1000

3.74K 1/4W

47.5K 1/4W

100 1/4W

R58,R76,R99,R100

R72, R900

S19400-3741

S19400-1501

S19400-2211

S19400-1301

S19400-1211

221K 1/4W

1.5K 1/4W

2.21K 1/4W

1.3K 1/4W

1.21K 1/4W

R77

R82,R175,R177

R78,R113,R114,R159

R79,R83,R155,R167

R80,R89

S19400-2213

S19400-1003

S19400-2431

S19400-8252

S19400-6811

S19400-26R7

S19400-2212

S19400-6812

S19400-2672

100K 1/4W

2.43K 1/4W

82.5K 1/4W

6.81K 1/4W

26.7 1/4W

R98

R97

R109

R120,R121,R122,R123

R130

22.1K 1/4W

68.1K 1/4W

26.7K 1/4W

R131,R174

R133,R173

R140,R141

R135,R183

R176

R129,R184

TP1,TP2

X1,X2

S19400-2670

S19400-1502

S19400-4750

S19400-5621

T13640-15

S15128-16

S15128-4

267 1/4W

15K 1/4W

475 1/4W

5.62K 1/4W

15J

LINEAR INTEGRATED CIRCUIT

LM224 OP-AMP

X4,X6

S15128-13

S24085-1

PRECISION OP AMP IC

ROM ASSEMBLY

S18647

REGULATOR ASBLY

5V REG. ASBLY

S18395-13

S15128-12

S15018-18

M15102-3

M15458-2

S15018-19

M15105-8

M13552-2

S16665-5

VOLTAGE REGULATOR

IC,ARRAY,CLAMPING

RESET I.C. UNDERVOLT. SENSING CIR. (SS)

PWM CONTROLLER I.C. (SS)

IC, DRIVER, FET, 6A

CMOS,CONVERTER,D/A,SERIAL,10-BIT (SS)

FREQ. TO VOLTAGE CONVERTER

8.0 MHZ

X10,X16

X11

X12

X13,X14

X15

X18

machine.

PROCUT 55

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G-9

ELECTRICAL DIAGRAMS

PC BOARD ASSEMBLY-CONTROL (G3328-2)

machine.

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G-10

ELECTRICAL DIAGRAMS

PC BOARD ASSEMBLY-OUTPUT (G3326-1)

machine.

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G-11

ELECTRICAL DIAGRAMS

PC BOARD ASSEMBLY-OUTPUT (G3326-2)

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G-12

ELECTRICAL DIAGRAMS

PC BOARD ASSEMBLY-POWER (G3172-1)

REQ'D

IDENTIFICATION

PART NO

ITEM

C1,C5,C8,C11

C2,C6,C9,C12

C3,C4,C14

S16668-6

4700pF/50

.0047/1000V

.022/50

S20500-4

S16668-5

S13490-93

S16668-9

S13490-130

S14293-18

27/35

C10

150pF/100

.27/50

C13

CR1

DPST RELAY

D1,D2,D3,D4,D5,D6,D7,D12

D13,D14

T12199-1

1N4004

J10

D8,D9,D10,D11

T12705-44

DIODE 1000V/1A

C R 1

T 1

DZ1,DZ5,DZ9,DZ12

DZ2,DZ3,DZ6,DZ7,DZ8,DZ10

DZ11,DZ13,DZ14

DZ4

T12702-40

1N4735

T12702-29

T12702-19

S20351-6

1N4744A

OCI2

B209

1N4742A

R60

D12

R57

J10

HEADER

R10

R69

OCI1,OCI2

S15000-22

OPTO ISOLATOR

R40

R31

R51

R50

R30

R29

R52

R55

R53

R56

R36

R35

R39

T12704-75

T12704-73

FET (SS)

B201

IC PKG MOSFET (SS)

R37

R1,R6,R20,R25,R41,R46,R62

S19400-10R0

10 1/4W

R67,R79,R80,R81,R82

B205

R2,R3,R4,R5,R21,R22,R23

S19400-1001

1K 1/4W

R25

R34

R24,R42,R43,R44,R45,R60

DZ12

R62

R81

R64

R65

R66

R63

C11

R63, R64,R65,R66

R75

R76

R7,R8,R26,R27,R47,R48,R68

T14648-21

2.7 OHM 5W

R69

R80

DZ2

DZ3

R10,R11,R12

T14649-4

100 10W

R13,R14,R15,R16,R34,R35

S19400-1503

150K 1/4W

R46

R50,R51,R83,R86

DZ13

DZ14

R17

S19400-1000

S19400-1821

S19400-2673

T10812-41

100 1/4W

DZ7

R18,R77

1.82K 1/4W

R19

267K 1/4W

R28

10K 1/2W TRIMMER

1500 OHM 5 WATT RESISTOR

R29,R30,R31,R32,R71,R72

T14648-12

R54

R98

D13

R73,R74

R33,R38,R58

R36,R52,R89,R90

R37,R55,R91,R92

R39,R53

R40,R56,R84,R87

R54

R86

C14

R28

S19400-3321

3.32K 1/4W

D14

B208

R79

S19400-6191

S19400-1502

6.19K 1/4W

15K 1/4W

R93

R83

R87

R78

R90

R85

R84

R88

R92

R91

R21

R22

R23

R24

R94

R38

R33

DZ10

R67

S19400-1652

16.5K 1/4W

S19400-3323

332K 1/4W

R45

R44

R43

R42

R95

R89

R26

S19400-1372

13.7K 1/4W

B204

R57,R59,R85,R88

R61

S19400-1002

10K 1/4W

PRO-CUT POWER

G3172-1

R97

C13

S19400-2213

221K 1/4W

R27

R82

R75

S19400-5620

S19400-2801

S19400-2001

S19400-4751

S19400-4752

S19400-2211

T12300-79

562 1/4W

R76,R98

R78

2.8K 1/4W

2.0K 1/4W

R93

4.75K

R94

47.5K 1/4W

2.21K 1/4W

1 WATT 1 OHM 1% RESISTOR

R95,R96

R97

S13000-46

TRANSFORMER

S15128-10

S15128-4

S15128-18

VOLTAGE REF.

LM224 OP-AMP

QUAD-OP AMP

machine.

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G-13

ELECTRICAL DIAGRAMS

PC BOARD ASSEMBLY-POWER (G3172-2)

machine.

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SVM ERROR REPORTING FORM

We need to know if there are errors in our manuals. We also value any suggestions as to

additional tests or procedures that would make this SVM a better tool for you.

If you discover new or different “Problems or Symptoms” that are not covered in the three col-

umn troubleshooting chart, please share this information with us. Please include the

machine’s code number and how the problem was resolved.

Thank You,

Technical Services Group

Lincoln Electric Co.

22801 ST. Clair Ave.

Cleveland, Ohio 44117-1199

FAX 216-481-2309

SVM Number ___________________________

Page Number if necessary__________________

Your Company__________________________

Your Name_____________________________

Please give detailed description below:

___________________________________________________________________________

SD287 01/99

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