RETURN TO MAIN MENU
IM908
October, 2006
PRECISION TIG 275
For use with machines having Code Numbers:
11370
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
READING THIS MANUAL AND
THE SAFETY PRECAUTIONS
CONTAINED
THROUGHOUT.
And, most importantly, think before
you act and be careful.
Precision TIG 275 shown with
optional Advanced Control
Panel and Under Cooler Cart
IP21S
OPERATOR’S MANUAL
Copyright © 2006 Lincoln Global Inc.
• 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
Download from Www.Somanuals.com. All Manuals Search And Download.
ii
ii
SAFETY
ARC RAYS can burn.
ELECTRIC SHOCK can kill.
3.a. The electrode and work (or ground) circuits
are electrically “hot” when the welder is on.
Do not touch these “hot” parts with your bare
skin or wet clothing. Wear dry, hole-free
gloves to insulate hands.
4.a. Use a shield with the proper filter and cover
plates to protect your eyes from sparks and
the rays of the arc when welding or observing
open arc welding. Headshield and filter lens
should conform to ANSI Z87. I standards.
4.b. Use suitable clothing made from durable flame-resistant
material to protect your skin and that of your helpers from
the arc rays.
3.b. Insulate yourself from work and ground using dry insulation.
Make certain the insulation is large enough to cover your full
area of physical contact with work and ground.
4.c. Protect other nearby personnel with suitable, non-flammable
screening and/or warn them not to watch the arc nor expose
themselves to the arc rays or to hot spatter or metal.
In addition to the normal safety precautions, if welding
must be performed under electrically hazardous
conditions (in damp locations or while wearing wet
clothing; on metal structures such as floors, gratings or
scaffolds; when in cramped positions such as sitting,
kneeling or lying, if there is a high risk of unavoidable or
accidental contact with the workpiece or ground) use
the following equipment:
FUMES AND GASES
can be dangerous.
• Semiautomatic DC Constant Voltage (Wire) Welder.
• DC Manual (Stick) Welder.
• AC Welder with Reduced Voltage Control.
5.a. Welding may produce fumes and gases
hazardous to health. Avoid breathing these
fumes and gases. When welding, keep
your head out of the fume. Use enough
ventilation and/or exhaust at the arc to keep
3.c. In semiautomatic or automatic wire welding, the electrode,
electrode reel, welding head, nozzle or semiautomatic
welding gun are also electrically “hot”.
fumes and gases away from the breathing zone. When
welding with electrodes which require special
ventilation such as stainless or hard facing (see
instructions on container or MSDS) or on lead or
cadmium plated steel and other metals or coatings
which produce highly toxic fumes, keep exposure as
low as possible and below Threshold Limit Values (TLV)
using local exhaust or mechanical ventilation. In
confined spaces or in some circumstances, outdoors, a
respirator may be required. Additional precautions are
also required when welding on galvanized steel.
3.d. Always be sure the work cable makes a good electrical
connection with the metal being welded. The connection
should be as close as possible to the area being welded.
3.e. Ground the work or metal to be welded to a good electrical
(earth) ground.
3.f. Maintain the electrode holder, work clamp, welding cable and
welding machine in good, safe operating condition. Replace
damaged insulation.
5. b. The operation of welding fume control equipment is affected
by various factors including proper use and positioning of the
equipment, maintenance of the equipment and the specific
welding procedure and application involved. Worker expo-
sure level should be checked upon installation and periodi-
cally thereafter to be certain it is within applicable OSHA PEL
and ACGIH TLV limits.
3.g. Never dip the electrode in water for cooling.
3.h. Never simultaneously touch electrically “hot” parts of
electrode holders connected to two welders because voltage
between the two can be the total of the open circuit voltage
of both welders.
5.c. Do not weld in locations near chlorinated hydrocarbon vapors
coming from degreasing, cleaning or spraying operations.
The heat and rays of the arc can react with solvent vapors to
form phosgene, a highly toxic gas, and other irritating prod-
ucts.
3.i. When working above floor level, use a safety belt to protect
yourself from a fall should you get a shock.
3.j. Also see Items 6.c. and 8.
5.d. Shielding gases used for arc welding can displace air and
cause injury or death. Always use enough ventilation,
especially in confined areas, to insure breathing air is safe.
5.e. Read and understand the manufacturer’s instructions for this
equipment and the consumables to be used, including the
material safety data sheet (MSDS) and follow your
employer’s safety practices. MSDS forms are available from
your welding distributor or from the manufacturer.
5.f. Also see item 1.b.
AUG 06
Download from Www.Somanuals.com. All Manuals Search And Download.
iii
iii
SAFETY
WELDING SPARKS can
cause fire or explosion.
CYLINDER may explode
if damaged.
6.a. Remove fire hazards from the welding area.
If this is not possible, cover them to prevent
7.a. Use only compressed gas cylinders
containing the correct shielding gas for the
the welding sparks from starting a fire.
Remember that welding sparks and hot
materials from welding can easily go through small cracks
and openings to adjacent areas. Avoid welding near
hydraulic lines. Have a fire extinguisher readily available.
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.
7.b. Always keep cylinders in an upright position securely
chained to an undercarriage or fixed support.
6.b. Where compressed gases are to be used at the job site,
special precautions should be used to prevent hazardous
situations. Refer to “Safety in Welding and Cutting” (ANSI
Standard Z49.1) and the operating information for the
equipment being used.
7.c. Cylinders should be located:
•Away from areas where they may be struck or subjected to
physical damage.
6.c. When not welding, make certain no part of the electrode
circuit is touching the work or ground. Accidental contact can
cause overheating and create a fire hazard.
•A safe distance from arc welding or cutting operations and
any other source of heat, sparks, or flame.
7.d. Never allow the electrode, electrode holder or any other
electrically “hot” parts to touch a cylinder.
6.d. Do not heat, cut or weld tanks, drums or containers until the
proper steps have been taken to insure that such procedures
will not cause flammable or toxic vapors from substances
inside. They can cause an explosion even though they have
been “cleaned”. For information, purchase “Recommended
Safe Practices for the Preparation for Welding and Cutting of
Containers and Piping That Have Held Hazardous
Substances”, AWS F4.1 from the American Welding Society
(see address above).
7.e. Keep your head and face away from the cylinder valve outlet
when opening the cylinder valve.
7.f. Valve protection caps should always be in place and hand
tight except when the cylinder is in use or connected for
use.
7.g. Read and follow the instructions on compressed gas
cylinders, 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.
6.e. Vent hollow castings or containers before heating, cutting or
welding. They may explode.
6.f. Sparks and spatter are thrown from the welding arc. Wear oil
free protective garments such as leather gloves, heavy shirt,
cuffless trousers, high shoes and a cap over your hair. Wear
ear plugs when welding out of position or in confined places.
Always wear safety glasses with side shields when in a
welding area.
FOR ELECTRICALLY
powered equipment.
6.g. Connect the work cable to the work as close to the welding
area as practical. Work cables connected to the building
framework or other locations away from the welding area
increase the possibility of the welding 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.
8.a. Turn off input power using the disconnect
switch at the fuse box before working on
the equipment.
8.b. Install equipment in accordance with the U.S. National
Electrical Code, all local codes and the manufacturer’s
recommendations.
6.h. Also see item 1.c.
8.c. Ground the equipment in accordance with the U.S. National
Electrical Code and the manufacturer’s recommendations.
Mar ‘95
Download from Www.Somanuals.com. All Manuals Search And Download.
iv
iv
SAFETY
PRÉCAUTIONS DE SÛRETÉ
Pour votre propre protection lire et observer toutes les instructions
et les précautions de sûreté specifiques qui parraissent dans ce
manuel aussi bien que les précautions de sûreté générales suiv-
antes:
6. Eloigner les matériaux inflammables ou les recouvrir afin de
prévenir tout risque d’incendie dû aux étincelles.
7. Quand on ne soude pas, poser la pince à une endroit isolé de
la masse. Un court-circuit accidental peut provoquer un
échauffement et un risque d’incendie.
Sûreté Pour Soudage A L’Arc
1. Protegez-vous contre la secousse électrique:
8. S’assurer que la masse est connectée le plus prés possible de
la zone de travail qu’il est pratique de le faire. Si on place la
masse sur la charpente de la construction ou d’autres endroits
éloignés de la zone de travail, on augmente le risque de voir
passer le courant de soudage par les chaines de levage,
câbles de grue, ou autres circuits. Cela peut provoquer des
risques d’incendie ou d’echauffement des chaines et des
câbles jusqu’à ce qu’ils se rompent.
a. Les circuits à l’électrode et à la piéce sont sous tension
quand la machine à souder est en marche. Eviter toujours
tout contact entre les parties sous tension et la peau nue
ou les vétements mouillés. Porter des gants secs et sans
trous pour isoler les mains.
b. Faire trés attention de bien s’isoler de la masse quand on
soude dans des endroits humides, ou sur un plancher met-
allique ou des grilles metalliques, principalement dans
les positions assis ou couché pour lesquelles une grande
partie du corps peut être en contact avec la masse.
c. Maintenir le porte-électrode, la pince de masse, le câble de
soudage et la machine à souder en bon et sûr état defonc-
tionnement.
d.Ne jamais plonger le porte-électrode dans l’eau pour le
refroidir.
e. Ne jamais toucher simultanément les parties sous tension
des porte-électrodes connectés à deux machines à souder
parce que la tension entre les deux pinces peut être le total
de la tension à vide des deux machines.
9. Assurer une ventilation suffisante dans la zone de soudage.
Ceci est particuliérement important pour le soudage de tôles
galvanisées plombées, ou cadmiées ou tout autre métal qui
produit des fumeés toxiques.
10. Ne pas souder en présence de vapeurs de chlore provenant
d’opérations de dégraissage, nettoyage ou pistolage. La
chaleur ou les rayons de l’arc peuvent réagir avec les vapeurs
du solvant pour produire du phosgéne (gas fortement toxique)
ou autres produits irritants.
11. Pour obtenir de plus amples renseignements sur la sûreté, voir
le code “Code for safety in welding and cutting” CSA Standard
W 117.2-1974.
f. Si on utilise la machine à souder comme une source de
courant pour soudage semi-automatique, ces precautions
pour le porte-électrode s’applicuent aussi au pistolet de
soudage.
2. Dans le cas de travail au dessus du niveau du sol, se protéger
contre les chutes dans le cas ou on recoit un choc. Ne jamais
enrouler le câble-électrode autour de n’importe quelle partie du
corps.
PRÉCAUTIONS DE SÛRETÉ POUR
LES MACHINES À SOUDER À
TRANSFORMATEUR ET À
REDRESSEUR
3. Un coup d’arc peut être plus sévère qu’un coup de soliel, donc:
a. Utiliser un bon masque avec un verre filtrant approprié ainsi
qu’un verre blanc afin de se protéger les yeux du rayon-
nement de l’arc et des projections quand on soude ou
quand on regarde l’arc.
b. Porter des vêtements convenables afin de protéger la peau
de soudeur et des aides contre le rayonnement de l‘arc.
c. Protéger l’autre personnel travaillant à proximité au
soudage à l’aide d’écrans appropriés et non-inflammables.
1. Relier à la terre le chassis du poste conformement au code de
l’électricité et aux recommendations du fabricant. Le dispositif
de montage ou la piece à souder doit être branché à une
bonne mise à la terre.
2. Autant que possible, I’installation et l’entretien du poste seront
effectués par un électricien qualifié.
4. Des gouttes de laitier en fusion sont émises de l’arc de
soudage. Se protéger avec des vêtements de protection libres
de l’huile, tels que les gants en cuir, chemise épaisse, pan-
talons sans revers, et chaussures montantes.
3. Avant de faires des travaux à l’interieur de poste, la debranch-
er à l’interrupteur à la boite de fusibles.
4. Garder tous les couvercles et dispositifs de sûreté à leur place.
5. Toujours porter des lunettes de sécurité dans la zone de
soudage. Utiliser des lunettes avec écrans lateraux dans les
zones où l’on pique le laitier.
Mar. ‘93
Download from Www.Somanuals.com. All Manuals Search And Download.
v
v
SAFETY
Download from Www.Somanuals.com. All Manuals Search And Download.
vi
vi
SAFETY
Download from Www.Somanuals.com. All Manuals Search And Download.
vii
vii
for selecting a QUALITY product by Lincoln Electric. We want you
to take pride in operating this Lincoln Electric Company product •••
as much pride as we have in bringing this product to you!
Thank You
Please Examine Carton and Equipment For Damage Immediately
When this equipment is shipped, title passes to the purchaser upon receipt by the carrier. Consequently, Claims
for material damaged in shipment must be made by the purchaser against the transportation company at the time
the shipment is received.
Please record your equipment identification information below for future reference. This information can be found
on your machine nameplate.
Product _________________________________________________________________________________
Model Number ___________________________________________________________________________
Code Number or Date Code_________________________________________________________________
Serial Number____________________________________________________________________________
Date Purchased___________________________________________________________________________
Where Purchased_________________________________________________________________________
Whenever you request replacement parts or information on this equipment, always supply the information you
have recorded above. The code number is especially important when identifying the correct replacement parts.
On-Line Product Registration
- Register your machine with Lincoln Electric either via fax or over the Internet.
• For faxing: Complete the form on the back of the warranty statement included in the literature packet
accompanying this machine and fax the form per the instructions printed on it.
• For On-Line Registration: Go to our WEB SITE at www.lincolnelectric.com. Choose “Quick Links” and then
“Product Registration”. Please complete the form and submit your registration.
Read this Operators Manual completely before attempting to use this equipment. Save this manual and keep it
handy for quick reference. Pay particular attention to the safety instructions we have provided for your protection.
The level of seriousness to be applied to each is explained below:
WARNING
This statement appears where the information must be followed exactly to avoid serious personal injury or
loss of life.
CAUTION
This statement appears where the information must be followed to avoid minor personal injury or damage to
this equipment.
Download from Www.Somanuals.com. All Manuals Search And Download.
viii
viii
TABLE OF CONTENTS
Page.
Installation ..........................................................................................................Section A
Technical Specifications ........................................................................................A-1,A-2
Safety Precautions.. ............................................................................................................................................... .A-3
Select Suitable Location........................................................................................A-3
Grinding .................................................................................................................A-3
Stacking.................................................................................................................A-3
Undercarriage Lifting and Moving .........................................................................A-3
Tilting .....................................................................................................................A-3
Environmental Rating ............................................................................................A-3
Machine Grounding and High FREQUENCY INTERFERENCE PROTECTION ...................A-3,A-4
Input and Grounding Connections..............................................................................A-4
Output Cable, Connections and Limitations ................................................................A-5
Work Cable Connection ..................................................................................A-5
Stick Electrode Cable Connection ..................................................................A-5
TIG Torch Connection .....................................................................................A-6
Auxiliary Power Connections ..........................................................................A-7
Remote Control (If Used)................................................................................A-7
Robotic Interface Connection ..................................................................A-7, A-8
________________________________________________________________________
OPERATION .........................................................................................................................................................Section B-1
Safety Precautions.......................................................................................................B-1
Product Description......................................................................................................B-1
Pipe Thawing.........................................................................................................B-1
Duty Cycle: ............................................................................................................B-1
Recommended Processes and Equipment...........................................................B-2
Controls and Settings ..........................................................................B-3 THRU B-6
Internal Set Up Controls........................................................................................B-7
Sick Welding Features...........................................................................................B-7
TIG Welding Features ...........................................................................................B-7
2 Step Trigger Modes......................................................................................B-8
4 Step Trigger Modes ....................................................................................B-9
TIG Welding Cycle Chart ....................................................................................B-10
Setup Guidelines for TIG Welding with an Amptrol.....................................B-10, B11
Making a TIG Weld with an Amptrol....................................................................B-12
________________________________________________________________________
Accessories ............................................................................................................................................... .......Section C
Optional Equipment .....................................................................................................C-1
________________________________________________________________________
Maintenance......................................................................................................................................................Section D
Safety Precautions.......................................................................................................D-1
Routine and Periodic Maintenance..............................................................................D-1
Overload Protection.....................................................................................................D-1
Service Procedures, Component Access,Spark Gap Adjustment...............................D-2
Under-Cooler Service ..................................................................................................D-2
________________________________________________________________________
Troubleshooting.............................................................................................................................................Section E
Safety Precautions.......................................................................................................E-1
How To Use TroubleShooting Guide............................................................................E-1
Troubleshooting.................................................................................................E-2 to E-7
________________________________________________________________________
Diagrams..............................................................................................................................................................Section F
Wiring Diagrams..............................................................................................................................................F-1, F-2
Dimension Prints.............................................................................................................................................F-3, F-4
________________________________________________________________________
Parts List......................................................................................................................................................................P-543
Download from Www.Somanuals.com. All Manuals Search And Download.
A-1
A-1
INSTALLATION
TECHNICAL SPECIFICATIONS-PRECISION TIG 275 (K1827-2 Export-50/60Hz)
RATED INPUT - SINGLE PHASE ONLY
Duty Cycle-Applications
Voltage + 10%
Max. Amps With Out
Max. Amps With
K
Power Factor Capacitor Power Factor Capacitor
Number
40%
AC/DC Stick / Balance TIG
Unbalance (70% Penetration#) AC TIG
60%
AC/DC Stick / Balance TIG
Unbalance (70% Penetration#) AC TIG
100%
80/46/43
86/50/46
95/55/50
109/63/58
K1827-2
220-230/
380-400/415
64/37/34
67/39/36
80/46/42
85/49/45
N80
AC/DC Stick / Balance TIG
Unbalance (70% Penetration#) AC TIG
Idle Amps
52/30/28
46/27/25
23/13/12
500W
70/41/37
65/38/35
10/6/5
IEC 60974-1
Idle Power
400W
RATED POWER FACTOR (STICK)
K1827-2
.65 min.
.77 min.
*Shown on Front of this IM manual with Advanced Control Panel (Refer to Optional Equipment)
#Exceeds NEMA Unbalanced Load Specification comparable for Auto-Balance.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
A-2
A-2
INSTALLATION
RATED OUTPUT - IEC 60974-1 (K1827-2)
Duty Cycle-Applications
Volts at Rated Amperes
Amps
40%
AC/DC Stick / Balance TIG
Unbalance (70% Penetration ) AC TIG
60%
31.0
20.2
275
255
#
AC/DC Stick / Balance TIG
Unbalance (70% Penetration ) AC TIG
29.0
18.0
225
200
#
100%
AC/DC Stick / Balance TIG
Unbalance (70% Penetration ) AC TIG
28.0
16.0
200
150
#
ADDITIONAL OUTPUT CAPACITY
Output Current
Range
Maximum Open
Type of Output
Auxiliary Power
Circuit Voltage
15Amp Circuit Breaker and NEMA 5-15R Duplex
Receptacle for up to:
2Amps DC
to
340Amps AC-DC*
115VAC 8Amp Auxiliary Power Receptacle
115VAC weld Switched Cooler Receptacle load
(STICK AND TIG)
AC/DC OCV: 75/68
CC (Constant Current)
AC/DC (GTAW)
Stick (SMAW)
5 Amp Circuit Breaker
and grounded 220VAC
Euro(Schuko) receptacle
RECOMMENDED INPUT WIRE AND FUSE SIZES
For all Stick, DC TIG, and Balanced AC TIG Welding
For Unbalanced AC TIG Welding Above 275 Amps:
255A/40% Duty Cycle, Auto-Balance Penetration with
out Standard Power Factor Correction Capacitors
Based on the 1999 U.S. National Electrical Code
at 275A/40% Duty Cycle with out Standard Power
Factor Correction Capacitors
Based on the 1999 U.S. National Electrical Code
Input
Ampere
(Super Lag) Rating
or Breaker Rating on
Type 75°C
Copper
Ground Wire in (Super Lag) Ampere
Conduit AWG or Breaker
(IEC) Sizes
Type 75°C
Copper Wire in
Conduit AWG
(IEC) Sizes
40°C (104°F)
Ambient
Type 75°C
Copper Wire in
Conduit AWG
(IEC) Sizes
40°C (104°F)
Ambient
Type 75°C
Copper
Ground Wire in
Conduit AWG
(IEC) Sizes
Input
Voltage /
phase/
Input
Fuse
Fuse
Rating
Size1
125
80
Nameplate
Size1
150
90
Frequency
2
2
2
2
220-230/1/50/60
380-400/1/50/60
415/1/50/60
95
55
50
6 (13.3 mm )
109
63
4 (21.2 mm )
4 (21.2 mm )
6 (13.3 mm )
2)
2)
2)
2)
8 (8.4mm
6 (13.3 mm
8 (8.4mm
8 (8.4 mm
2)
2)
2)
2)
90
58
80
8 (8.4mm
6 (13.3 mm
8 (8.4mm
8 (8.4 mm
PHYSICAL DIMENSIONS
Height
Width
Depth
26.0 in.
660 mm
Weight
Approx. 397 lbs.
180 kgs.
31.0 in.
22.0 in.
559 mm
K1827-2
787 mm
TEMPERATURE RANGES
OPERATING TEMPERATURE RANGE
STORAGE TEMPERATURE RANGE
-40°C to +85°C (-40° to +185°F)
-20°C to +40°C (-04° to +104°F)
TRANSFORMER INSULATION CLASS 180°C (H)
1 ALSO CALLED ‘INVERSE TIME" OR "THERMAL/MAGNETIC " CIRCUIT BREAKERS; CIRCUIT BREAKERS WHICH HAVE A DELAY IN TRIPPING ACTION THAT DECREASES AS
THE MAGNITUDE OF CURRENT INCREASES.
*
50/60HZ IEC Max. range exceeds 310A.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
A-3
A-3
INSTALLATION
ENVIRONMENTAL RATING
SAFETY PRECAUTIONS
Read entire installation section before starting
installation.
Precision TIG 275 power sources carry an IP21S
Environmental rating. They are rated for use in damp,
dirty rain-sheltered environments.
WARNING
MACHINE GROUNDING AND HIGH FRE-
QUENCY INTERFERENCE PROTECTION
ELECTRIC SHOCK can kill.
• Only qualified personnel should
perform this installation.
• Turn the input power OFF at the
disconnect switch or fuse box
before working on this
equipment.
The frame of the welder must be grounded. A ground screw
marked with the symbol is located on the input connection
panel (Figure A.1) for this purpose. See your local and nation-
al electrical codes for proper grounding methods.
• Do not touch electrically hot
parts.
The spark gap oscillator in the high frequency genera-
tor, being similar to a radio transmitter, can be blamed
for many radio, TV and electronic equipment interfer-
ence problems. These problems may be the result of
radiated interference. Proper grounding methods can
reduce or eliminate radiated interference.
• Always connect the Precision TIG 275 grounding screw (behind
the reconnect panel cover located near the back of the left case
side) to a good electrical earth ground.
• Always connect the Precision TIG 275 to a power supply
grounded in accordance with the National Electrical Code and
all local codes.
SELECT SUITABLE LOCATION
The Precision TIG 275 has been field tested under rec-
ommended installation conditions and has been found
to comply with F.C.C. allowable radiation limits. This
welder has also been found to comply with NEMA stan-
dards for high frequency stabilized power sources.
Place the welder where clean cooling air can freely cir-
culate in through the top rear vents and out through the
bottom rear vents. Dirt, dust or any foreign material
that can be drawn into the welder should be kept at a
minimum. Failure to observe these precautions can
result in excessive operating temperatures and nui-
sance trips.
Radiated interference can develop in the following four
ways:
• Direct interference radiated from the welder.
• Direct interference radiated from the welding leads.
• Direct interference radiated from feedback into the
power lines.
• Interference from re-radiation of "pickup" by
ungrounded metallic objects.
GRINDING
Do not direct grinding particles towards the welder. An
abundance of conductive material can cause mainte-
nance problems.
STACKING
The Precision TIG 275's cannot be stacked .
Keeping these contributing factors in mind, installing
the equipment per the following instructions should
minimize problems.
UNDERCARRIAGE LIFTING AND MOVING
1. Keep the welder power supply lines as short as
possible. Input leads within 50 feet (15.2 m) of the
welder should be enclosed in rigid metallic conduit
or equivalent shielding. There must be good electri-
cal contact between this conduit and the welder.
Both ends of the conduit must be connected to a
driven ground and the entire length must be contin-
uous.
When the Precision TIG 275 is purchased as a weld-
ing package, or used with any of the available
Undercarriage optional accessories, proper installation
makes the Precision TIG 275 lift bale nonfunctional.
Do not attempt to lift the power source with an under-
carriage attached. The undercarriage is designed for
hand moving only; mechanized movement can lead to
personal injury and/or damage to the Precision TIG
275.
2. Keep the work and electrode leads as short as pos-
sible and as close together as possible. Lengths
should not exceed 25 feet (7.6 m). Tape the leads
together when practical.
TILTING
Each machine must be placed on a secure, level sur-
face, either directly or on a recommended undercar-
riage. The machine may topple over if this precaution
is not followed.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
A-4
A-4
INPUT and GROUNDING CONNECTIONS
INSTALLATION
3. Be sure the torch and work cable rubber coverings
are free of cuts and cracks that allow high frequen-
cy leakage. Cables with high natural rubber content,
such as Lincoln Stable-Arc® better resist high fre-
quency leakage than neoprene and other synthetic
rubber insulated cables.
WARNING
ELECTRIC SHOCK can kill.
• Turn the input power OFF at the
disconnect switch or fuse box
before working on this
equipment.
4. Keep the torch in good repair and all connections
tight to reduce high frequency leakage.
Be sure the voltage, phase, and frequency of the input
power is as specified on the rating plate, located on the
rear of the machine.
5. The work terminal must be connected to a ground
within ten feet of the welder, using one of the fol-
lowing methods:
Fuse the input circuit with the recommended super lag
fuses or delay type1 circuit breakers. Choose an input
and grounding wire size according to local or national
codes or use Section A-2. Using fuses or circuit break-
ers smaller than recommended may result in "nui-
sance" tripping from welder inrush currents even if not
welding at high currents.
• A metal underground water pipe in direct contact
with the earth for ten feet or more.
• A 3/4" (19 mm) galvanized pipe or a 5/8" (16 mm)
solid galvanized iron, steel or copper rod driven at
least eight feet into the ground.
The ground should be securely made and the ground-
ing cable should be as short as possible using cable of
the same size as the work cable, or larger. Grounding
to the building frame electrical conduit or a long pipe
system can result in re-radiation, effectively making
these members radiating antennas. (This is not rec-
ommended).
Unbalanced AC TIG welding draws higher input cur-
rents than those for Stick, DC TIG, or Balanced AC TIG
welding. The welder is designed for these higher input
currents. However, where unbalanced AC TIG welding
above 185 amps is planned, the higher input currents
require larger input wire sizes and fuses per Section A-2:
Remove the reconnect panel cover located near the
back of the left case side to reveal the reconnect panel.
Welder supply line entry provision is in the case rear
panel. Entry is through a 1.75 inch (44 mm) diameter
hole in the case back. Appropriate supply line strain
relief clamp is provided by installer. (See Figure A.1)
6. Keep all access panels and covers securely in
place.
7. All electrical conductors within 50 feet (15.2 m) of
the welder should be enclosed in grounded rigid
metallic conduit or equivalent shielding. Flexible
helically-wrapped metallic conduit is generally not
suitable.
FIGURE A.1
8. When the welder is enclosed in a metal building,
several good earth driven electrical grounds (as in 5
above) around the periphery of the building are rec-
ommended.
CONNECT INPUT
POWER LEADS
CONNECT INPUT
CONNECT INPUT
GROUND LEAD
VOLTAGE LEVEL
Failure to observe these recommended installation
procedures can cause radio or TV interference prob-
lems and result in unsatisfactory welding performance
resulting from lost high frequency power.
All connections should be made in accordance
with all local codes and national electrical codes.
Installation by a qualified electrician is recom-
mended.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
A-5
A-5
INSTALLATION
1. Connect the terminal marked
nect panel) to an earth ground.
(below the recon-
Recommended Cable Sizes for Combined Lengths of
Copper Work and Electrode Cables using 75 C Wire:
o
Machine Rating
0 to 100 Ft.
101 to 200 Ft
201 to 250 Ft
2. Connect the input leads to terminals marked L1 (U)
and L2 (V) on the reconnect panel. Use a single
phase line or one phase of a two or three phase line.
2
2
2
275A/40%
#1 (42.4 mm ) 1/0 (53.5 mm ) 2/0 (67.4 mm )
WORK CABLE CONNECTION
3. On multiple input voltage welders, be sure the
reconnect panel is connected for the voltage being
supplied to the welder.
A 15’ (2/0) weld cable with clamp is available (K2150-1), or
included with the Precision TIG Welding Package model.
Otherwise, it is user provided.
CAUTION
Failure to follow these instructions can cause
immediate failure of components within the welder.
------------------------------------------------------------------------
With power source off, connect a separate work cable
to the 1/2-13 threaded "WORK" stud of the welder, and
secure a tight connection with the flange nut provided.
The work cable should be routed through the cable
strain relief hole provided in the base directly below the
welding output terminal.
Note: If the Precision TIG is equipped with an Under-
Cooler or Under-Storage unit, the coiled work cable
and clamp, or excess work cable length, may be con-
veniently stored in the drawer while remaining con-
nected.
Welders are shipped connected for the highest input
voltage as listed on the rating plate. To change this
connection, designations on the reconnect panel LOW,
MID, and HIGH correspond to the name plated input
voltages of a triple voltage welder. Dual voltage
welders use only LOW and HIGH.
STICK ELECTRODE CABLE CONNECTION
EXAMPLE: On a 208/230/460 volt welder, LOW is
208V, MID is 230V, and HIGH is 460V.
Note: Export model has a voltage range for LOW and
MID connections: LOW is 220-230V, MID is
380-400V and High is 415V.
If manual stick welding is desired, with power source
off, connect a stick electrode cable to the 1/2-13
threaded "STICK Electrode" stud of the welder, and
secure a tight connection with the flange nut provided.
The electrode cable should be routed through the
cable strain relief hole provided in the base directly
below the welding output terminal.
Reconnect the jumper strap to the terminal stud corre-
sponding to the input voltage level used. Make sure all
connections are tight.
OUTPUT CABLES, CONNECTIONS AND
LIMITATIONS
WARNING
DISCONNECT STICK ELECTRODE WELDING
CABLE WHEN TIG WELDING.
WARNING
EVEN THOUGH HI-FREQ IS NOT APPLIED TO THE
PRECISION TIG STICK TERMINAL, IT WILL BE
ELECTRICALLY "HOT" TO WORK WHEN TIG
WELDING.
• To avoid being startled by a high frequency
shock, keep the TIG torch and cables in good
condition
• Turn the power switch of the power source OFF
before installing adapters on cable or when con-
necting or disconnecting adapter plugs to power
source.
------------------------------------------------------------------------
-----------------------------------------------------------------------
Refer to Figure A.2 for the location of the WORK and
STICK terminals, as well as the TIG Torch connection
panel.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
A-6
A-6
INSTALLATION
FIGURE A.2
TIG TORCH
CONNECTION
PANEL
REMOTE
CONTROL
RECEPTACLE
STICK
WORK
WORK
STICK
ELECTRODE
STUD
STUD
(Shown without hinged stud cover)
FIGURE A
CABLE
STRAIN
RELIEF HOLES
TIG TORCH CONNECTION
CYLINDER could explode
if damaged.
The Precision TIG torch connection box, located on the
right side of the machine, provides all the input and
output connections for the installation of both air-
cooled and water-cooled TIG torches with fittings con-
forming to Compressed Gas Association (CGA) stan-
dards:
Note: The Precision TIG provides an insulated Torch
Reel and Holster for handy and safe storage of con-
nected torch when not welding, and excess torch cable
length while welding.
• Keep cylinder upright and
chained to a support.
• Keep cylinder away from areas
where it could be damaged.
• Never allow the torch to touch the cylinder.
• Keep cylinder away from live electrical cir-
cuits.
• Maximum inlet pressure 150 psi.
-----------------------------------------------------------------
The Precision TIG machines do not have Hi-Freq.
available at the Stick electrode stud, therefore stud
connection adapters (such as LECO. S19257-series)
cannot be used for torch connection.
WARNING
Combination connectors (Power/Water and
Power/Gas) are electrically "hot" while welding in
STICK or TIG modes.
Single-piece cable air-cooled torches with a 3/8-24 RH
connector fitting (such as the Magnum PTA-9/-17, or LA-
9/-17) require the provided S20403-4 Torch Connector,
while those with a 7/8-14 RH connector fitting (such as
the Magnum PTA-26, or LA-26) require the available
K2166-1 Torch Connector. (See Figure A.3)
If using an Air-Cooled Torch be sure coolant is
shut off and/or Cooler is unplugged from the
Precision TIG Water Cooler Receptacle on the
torch side of the upper case back.
Two-piece cable air-cooled torches (such as PTA-, or LA-
torches) can be used with the available 1/2” Stud
Connector (S20403-3) with with a 7/8-14 LH male fitting.
Observe the safety precautions necessary for han-
dling and using compressed gas containers.
Contact your supplier for specifics.
Magnum PTW-18/-20 (or LW-) water-cooled Torches
require no adapter for Precision TIG connection.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
A-7
A-7
INSTALLATION
FIGURE A.3
For Gas Supply hose
with 5/8-18RH male
(Provided with Weld
Package model)
For Coolant Supply
Hoses
with 5/8-18LH male
(Provided with Weld
Package model
or
Under-Cooler Cart)
The Precision TIG Export models also provide a
grounded 220vac Euro type Schuko receptacle and a
5 amp circuit breaker, located on the upper case back
on the reconnect side of the machine, intended for use
with a 220vac water cooler.
AUXILIARY POWER CONNECTIONS
The Precision TIG machines provide a standard NEMA
5-15R duplex receptacle, located on the upper case
back on the torch side of the machine:
• The bottom outlet of this duplex receptacle provides
switched 115VAC power for the Under-Cooler, or
Water Solenoid accessory. This Cooler receptacle
turns on when the arc starts and remains on for about
8 minutes after the arc goes out (with the Fan-As-
Needed machine cooling fan, see Maintenance
Section), so the Cooler’s fan and water pump will not
run continuously in idle, but will run while welding.
REMOTE CONTROL (If Used)
The Foot Amptrol (included with the Precision TIG
Welding Package), or other Remote accessory, is
installed by routing the plug of its control cable up
through the left cable strain relief hole provided in the
base (see Figure A.2), then connecting the 6-pin plug
to the mating Remote receptacle behind the stud panel
cover. (See Operation Section B-2 for mating plug
wiring.)
Note: If the Precision TIG is equipped with an Under-
Cooler or Under-Storage unit, the Foot Pedal (or other
remote control accessory) and coiled control cable, or
excess cable length, may be conveniently stored in the
drawer while remaining connected.
• The top outlet of this duplex receptacle provides at
least 8 amps at 115VAC, whenever the Precision TIG
Power switch is ON. This auxiliary circuit is intended
for running 115VAC accessories or small power tools.
Note: Some types of equipment, especially pumps
and large motors, have starting currents which are
significantly higher than their running current. These
higher starting currents may cause the circuit breaker
to open. (See next paragraph)
• Both the receptacle circuits are protected from shorts
and overloads by a 15 amp circuit breaker, located
above the receptacle. if the breaker trips its button
pops out exposing a red ring. When the circuit break-
er cools the button can be reset by pressing it back
in.
Note: When the breaker trips not only will the auxil-
iary and cooler power be interrupted, but so will the
power to the shielding gas solenoid and machine
cooling fan.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
A-8
A-8
INSTALLATION
ROBOTIC INTERFACE CONNECTION
Robotic interface can be made at the Remote
Receptacle (See Operation Section B-2). The machine
is shipped with the remote receptacle circuit internally
connected to receptacle J5 of the Control board for
standard Amptrol operation. In order to enable the
remote receptacle for robotic interface its connection
plug must be moved from J5 to J5A on the Control
board. (Refer to the machine Wiring Diagram.)
The robotic interface functions with the Precision TIG
set to either TIG or STICK mode, but must be in
REMOTE switch position for the Preset Control inter-
face to function. When in the REMOTE position with
robotic interface neither the MAXIMUM OUTPUT nor
the MINIMUM OUTPUT panel controls limit the inter-
face control setting over the rated output range of the
machine.
The diagram in Figure A.4 below shows the remote
receptacle plug connections and signals for robotic
interface:
REMOTE RECEPTACLE
FIGURE A.4
(Front View)
For 18-12P Plug
(LECO S12020-27)
PRESET CONTROL
INPUT FROM ROBOT
(0 -10Vdc = Rated Output Range)
C
Note: The Interface connection
cable may pick up noise
+VCC = 70Vdc max.
B
A
D
E
ARC START
INPUT FROM ROBOT
(18Vac,10ma switch)
*
interference. Additional
bypass/filtering circuits may be
needed for the external circuits.
R = VCC / 5ma
5ma
F
ARC ESTABLISHED
OUTPUT TO ROBOT
(High = Not Welding)
(Low = Welding)
Robotic
Common
*
Precision TIG Control Common.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
B-1
B-1
OPERATION
SAFETY PRECAUTIONS
PRODUCT DESCRIPTION
Read and understand this entire section before operat-
ing the machine.
The Precision TIG 275 is part of a new family of indus-
trial arc welding power sources providing constant cur-
rent, single range square wave AC/DC TIG (GTAW)
TM
with new patented (pending) Micro-Start Technology,
WARNING
Presettable Min. and Max. Output controls, and built-in
high frequency stabilization for continuous AC TIG and
DC TIG starting. It also has AC/DC Stick (SMAW)
capability, with adjustable Arc Force availability. A TIG
Pulse Panel, Power Factor Capacitors and a Water
Solenoid are available as field installed optional kits.
Also, a new Undercarriage (with double gas bottle
rack) is available for field installation, as well as a new
Under-Cooler Cart, which is also included in an avail-
able efficiently integrated entire TIG Welding Package
with convenient built-in storage provisions for welding
equipment and components.
ELECTRIC SHOCK can kill.
• Only qualified personnel should
perform this installation.
• Turn the input power OFF at the
disconnect switch or fuse box.
• Do not touch electrically live parts
or electrode with skin or wet cloth-
ing.
•
Insulate yourself from work and
ground.
• Always wear dry insulating gloves.
•
Read and follow “Electric Shock
Warnings” in the Safety section if weld-
ing must be performed under electrical-
ly hazardous conditions such as weld-
ing in wet areas or on or in the work-
piece.
The Precision TIG 275 includes advanced features
such as a Digital Meter, Presettable control, Auto
TM
Balance , Fan As Needed (F.A.N.) fixed Preflow, vari-
able Postflow shielding gas and Timers. In addition, 2-
Step/4-Step and Pulse TIG operation with adjustable
Downslope Time control are included with an available
field installed kit. It also features a Stick stud panel and
a universal TIG torch connection box for simultaneous,
but separated, electrode outputs.
FUMES AND GASES
can be dangerous.
• Keep your head out of fumes.
• Use ventilation or exhaust to
remove fumes from breathing
zone.
PIPE THAWING
The Precision TIG 275 is not recommended for pipe
thawing.
WELDING SPARKS
can cause fire or
explosion
Duty Cycle
• Keep flammable material away.
• Do not weld on containers that
have held combustibles.
The duty cycle is based upon a 10-minute time period;
i.e., for 40% duty cycle, it is 4 minutes welding and 6
minutes idling. If the rated duty cycle is significantly
exceeded, the thermostatic protection will shut off the
output until the machine cools to a normal operating
temperature. (Refer to Specification Section A-1)
ARC RAYS
can burn.
• Wear eye, ear and body
protection.
Observe additional Safety Guidelines detailed in
the beginning of this manual.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
B-2
B-2
OPERATION
EQUIPMENT LIMITATIONS
RECOMMENDED PROCESSES AND
EQUIPMENT
The Precision TIG machines are protected from over-
loads beyond the electrical ratings and duty cycles, per
the Specifications Section A-1, A-2, with Thermostat
protection of the primary and secondary transformer
coils.
RECOMMENDED PROCESSES
The Precision TIG 275 is recommended for the TIG
(GTAW) and Stick (SMAW) welding processes within
its output capacity range of 2 amps DC, or 5 amps AC,
to 340 amps AC/DC. It is compatible with most
Magnum TIG accessories (refer Equipment
Limitations), as well as many industry standard items,
such as TIG torches, hoses, and water coolers.
The Precision TIG machines do not have Hi-Freq.
available at the Stick electrode stud, therefore stud
connection adapters (such as LECO. S19257-series)
cannot be used for torch connection.
PROCESS LIMITATIONS
Precision TIG machines are not recommended for arc
gouging due to it's limited output capacity, and are also
not recommended for pipe thawing.
RECOMMENDED EQUIPMENT/INTERFACE
TIG (air cooled)
Machine:
PT275 K1827-2)
User provided
LE/Harris 3100211
PTA9 or PTA17
KP507 or KP508
K2150-1 Work Lead Assembly
K870 or K870-1
Input Cable/Clamp:
Gas Reg./Hose:
Magnum Torch:
Magnum Parts:
Work Clamp/Lead:
Foot Amptrol:
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
B-3
B-3
OPERATION
CONTROLS AND SETTINGS
The Front Control Panel contains the knobs and switches necessary for adjusting the operation of the Precision
TIG 275, with function indicator lights and an electronic display for volts and amps. The components are
described below:
FIGURE B.1 - CONTROL PANEL
1. POWER SWITCH
2. POLARITY SWITCH
3. MODE SWITCH
4. AC BALANCE CONTROL
5. LOCAL/REMOTE CURRENT CONTROL
SWITCH
6. MAXIMUM OUTPUT CONTROL
7. MINIMUM OUTPUT CONTROL AND
DISPLAY SWITCH
8. DIGITAL METER AND DISPLAY
SWITCH
9. POSTFLOW TIME
10. THERMAL SHUTDOWN LIGHT
11. REMOTE RECEPTACLE
12. TRIGGER SWITCH
13. PULSE MODE SWITCH
14. PULSE FREQUENCY CONTROL
15. PULSE % ON TIME CONTROL
16. PULSE BACKGROUND CURRENT
CONTROL
17. DOWNSLOPE TIME
1. POWER SWITCH - Input line switch turns input
power ON or OFF, as indicated by the on or off sta-
tus of the front panel displays.
• The CC Stick mode may be used for general pur-
pose stick welding (SMAW ) within the capacity of
the machine. The capacity is too limited for arc air
carbon (AAC) gouging.
2. POLARITY SWITCH – The 3-position rotary power
switch has detente positions for DC-, AC and DC+
selections for the Electrode output welding polarity.
• In this mode; the output terminals are activated
electrically HOT, gas flow is not activated and HOT
START and ARC FORCE levels are fixed, or
Advanced Panel selectable (See Section B-7 ), with
no front panel adjustment.
3. MODE SWITCH – The mode switch allows vertical-
ly positioned selection of the two machine welding
modes. The selected mode is indicated by a lit col-
ored panel light which permits viewing the machine
setting from a distance:
3.b TIG mode (Bottom position) – No panel light.
• When the Polarity Switch is set to AC, the TIG
mode provides continuous high frequency to stabi-
lize the arc for AC TIG welding.
3.a STICK mode (Top position) –Red panel light
WARNING
Hi-Freq. turns on after preflow time with the arc
start switch closure, and turns off when the arc
goes out* after the arc start switch opens.
ELECTRIC SHOCK can kill.
• When the Power Source is ON in
STICK mode the Electrode circuits of
both the Stick and TIG torch cables
* Arc voltage and current are sensed to determine if
the arc is established or out.
are electrically HOT to Work.
------------------------------------------------------------------------
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
B-4
B-4
OPERATION
• When the Polarity Switch is set to DC (- or +), the
TIG mode provides high frequency only for starting.
• With the Current Control switch to REMOTE posi-
tion, this knob sets the maximum welding level that
the Peak output can be set with the remote Amptrol.
Hi-Freq. turns on after pre-flow time with the arc
start switch closure, and turns off when the arc is
established*
TM
• The new MicroStart Technology minimum current
circuit provides for low end welding (down to 2
amps) previously unobtainable on an SCR platform
TIG machine.
• Also functions for DC+ polarity to permit "balling" of
tungsten for AC TIG welding.
7. MINIMUM OUTPUT CONTROL AND DISPLAY SWITCH
–
4. AC BALANCE CONTROL – The potentiometer
control permits AC wave balance adjustment from
Max. Penetration (~85% negative wave) with the
control at Max. full CW position, to Max. Cleaning
(~65% positive wave) with the control set near min-
imum CCW position.
A smaller knob is used to preset the minimum cur-
rent level only for TIG mode. Pressing the Display
(momentary) switch toggle left to Minimum Set posi-
tion displays the Minimum control level setting on the
Digital meter. (See Item 8)
• This knob sets the Start output level. When the arc
lights (using a new built-in TIG start pulse) this level
upslopes quickly (0.5 sec.w/ Advanced Panel, zero
w/o) and smoothly to the weld output level. The set-
ting range for this Start control is the 2 amp mini-
mum range of the machine up to about 50 amps, but
no more than the level set by the Maximum Output
control knob (See Item 6), but otherwise is indepen-
dent of the Maximum setting.
• Full minimum CCW position is the Auto Balance
position which is indicated by the Green panel light
turning on. This feature automatically provides the
proper amount of cleaning and penetration for nor-
mal AC TIG welding
• The mid position is the Balanced position (~50%
positive and negative waves).
• The Balance control is only functional if the machine
is set to AC polarity and TIG mode.
• This setting also serves as the Crater-fill level, but
with a Precision TIG Advanced Panel it can be
selected (see Section B-7) to be either the Minimum
Output control setting (same as Start setting) as
shipped, or the minimum rating of the machine (2
amps).
5. LOCAL/REMOTE CURRENT CONTROL SWITCH – A
2-position switch selects how the welding output is
controlled for both Stick and TIG Modes:
• LOCAL (Top position) selects output control only by
the machine panel Output Control. (See Item 6)
• The Remote Amptrol range of control is between
this Minimum setting and the Maximum Output con-
trol knob setting, so these knobs can set the resolu-
tion of the Amptrol. Also, the Minimum setting
serves as both the minimum Amptrol start level
when the arc start switch is closed, as well as the
minimum Amptrol crater-fill level before the arc start
switch is opened to help prevent premature arc out
and Hi-Freq re-initiation.
• REMOTE (Bottom position) selects output control to
also be by an Amptrol (See Item 6), or other remote
(10K pot) control connected to the Remote recepta-
cle (See Item 11) This switch selection is indicted by
the Green panel light turning on.
In either position the arc start switch functions when
connected to the Remote receptacle (See Item 11).
.
• In STICK mode the Start control is not functional
since Hot Start level is fixed, or internal Advanced
Panel adjustable (see Section B-7). Pressing the
Display (momentary) switch toggle left to Minimum
Output position displays minimum amps rating of
the machine.
6. MAXIMUM OUTPUT CONTROL – The large knob
is used to set the output welding current over the
rated output range of the machine.
• With the Current Control switch to LOCAL position,
this knob sets the welding output level.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
B-5
B-5
OPERATION
8. DIGITAL METER AND DISPLAY SWITCH– A 3-
digit LED meter is used to monitor the preset and
actual welding procedure based on the Display
(momentary) switch position:
• When the Current Control Switch is in either LOCAL
or REMOTE positions the arc start switch functions
when connected to the Remote receptacle.
FIGURE B.2
• Before welding with Display switch in center (nor-
mal) position, the digital meter displays the preset
welding amps set by Maximum Output control knob
(See Item 6). If in Stick mode using REMOTE (See
Item 5.), the digital meter displays the preset weld-
ing amps set by the Remote control. (See Item 11)
• While welding with Display switch in center (normal)
position, the digital meter displays the actual weld-
ing amps with one amp resolution (XXX) and accu-
racy within 4%+/-2A of reading.
• Any time in TIG mode and while pressing the
Display switch to left, the digital meter displays the
amps preset by the Minimum Output control knob
(See Item 7).
• Any time in Stick mode and while pressing the
Display switch to left, the digital meter displays the
minimum amps rating of the machine (See Item 7).
• Any time, in either mode, while pressing the Display
switch right to Volts position, the digital meter dis-
plays actual output volts. Volts is displayed with 0.1
volt resolution (XX.X) and accuracy within 3%+/-1V
of reading.
REMOTE RECEPTACLE*
(Front View)
ARC START
SWITCH
REMOTE OUTPUT
CONTROL
C
F
Max
B
A
D
E
10K ohm
Min
*For 18-12P Plug
(LECO S12020-27)
ADVANCED PANEL CONTROLS
The following controls are included only if the Precision
TIG 275 has the Advanced Control Panel (K1829-1)
option installed: (Refer to Section B-10 Tig Weld Cycle
Chart for graphic illustration of these TIG welding func-
tions.)
12. TRIGGER SWITCH – This 2-position switch
selects how the arc start switch ( connected to the
above Remote receptacle) functions; in 2-Step or 4-
Step mode:
CAUTION
• DO NOT USE 4-STEP IF USING AN AMPTROL
REMOTE.
• Neither the arc start switch nor the output con-
trol in the amptrol will function normally to shut
off or control the out put. ONLY USE 2-STEP.
------------------------------------------------------------------------
• In 2-Step position the arc start switch functions the
same as without the Advanced Panel:
9. POSTFLOW TIME – This knob is used to set the
TIG mode shielding gas postflow time over the
range of about 2 to 60 seconds after the arc is shut
off. The postflow on time status is indicated by the
Green panel light.
• Gas preflow time for TIG mode is fixed at 0.5 sec-
ond, with no panel control.
• Both time ranges are x2 extendable, if needed, by
internal control box selection. (See Section B-7)
1. Closing switch starts preflow, then a fixed
(0.5 sec.) ramp time from Minimum (Start)
setting level (See Item 7) to Weld setting.
10. THERMAL SHUTDOWN LIGHT – This yellow LED
panel light turns on if the machine output is shut-
down because internal overheating has occurred,
and turns off when the thermostat resets.
2. Opening switch initiates Downslope ramp
time setting (See Item 17), from Weld set-
ting to Crater-fill level (See Item 7), which
then stops the arc and initiates Postflow
time (See Item 9).
11. REMOTE RECEPTACLE – A 6-socket receptacle
is provided for the connection of an Amptrol, or
other, remote control: (See Figure B.2)
Note: See Section B-7 for 2-Step operation during
Downslope with Restart feature selected to be dis-
abled, instead of enabled (as shipped).
• When the Current Control Switch, (See Item 5), is
in the REMOTE position the Amptrol, or other
remote (10K pot), connected to the Remote recep-
tacle controls the TIG or Stick mode output within
the range preset by the Maximum and Minimum
Output controls. (See Item 6 and Item 7, also 8 for
meter display)
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
B-6
B-6
OPERATION
• In 4-Step position allows welding without continu-
ously holding the start switch trigger. The arc start
switch functions in the following manner:
16. PULSE BACKGROUND CURRENT CONTROL –
This knob controls the level of the Background Current
as a percentage (MIN.-100%) of the Peak (REMOTE
and/or LOCAL) output level (See Item 6) down to the
Minimum Output setting (See Item 7).
1. Closing switch starts preflow, then arc starts
at Minimum (Start) setting level (See Item
7). If the trigger is maintained closed after
preflow time the output remains at the Start
level until it is released.
17. DOWNSLOPE TIME– This knob is used to set the
time, over the range of zero to about 10 seconds, to
ramp down from weld setting to Crater-fill level (See
Item 7).
2. Opening switch initiates fixed (0.5 sec.)
ramp time from Start setting level to Weld
setting.
• If the arc goes out after the Downslope time is initi-
ated, the Downslope time is interrupted and the
Postflow time is initiated. This prevents Hi-Freq re-
initiation during ramp down crater fill
3. Reclosing switch initiates Downslope ramp
time setting (See item 17) from Weld setting
down to the Crater-fill level (See Item 7) of
the machine.
• When using an Amptrol remote control, where the
downslope is controlled by the operator down to the
crater-fill level, the Downslope time should be set to
zero so as not to have the Downslope time delay
when the arc start switch is opened.
4. Reopening switch after Downslope time
holds Crater-fill level until switch opens,
then stops the arc and initiates the Postflow
Time (See Item 9). Or, reopening switch
during Downslope time immediately stops
the arc and initiates the Postflow.
Note: See Section B-7 for 4-Step operation during
Downslope with Restart feature selected to be
enabled, instead of disabled (as shipped).
13. PULSE MODE SWITCH – Turns on the Pulse
Mode as indicated by the Green panel light turning on.
• Pulsing provides a Peak current level set by
REMOTE and/or LOCAL control of the output cur-
rent (See Item5), for a time determined by the Pulse
Frequency Control setting (See Item 14) and the %
ON Time (See Item 15). The balance of the cycle
time is at the Background Current level (See Item
16).
• Pulsing begins after upslope when the output cur-
rent rises above the Background Current level and
ends when the output current drops below this level.
14. PULSE FREQUENCY CONTROL – This knob is
used to set the Pulse Frequency over the peak pulse
range of about 0.1 pps to 20 pps. (One pulse cycle
time = 1/pps = 10 to .05 sec. range.)
15. PULSE % ON TIME CONTROL – This knob con-
trols the duration of the peak current as a percentage
(5% to 95%) of one pulse cycle. The balance of the
cycle time will be at the Background Current setting.
(See Item 16)
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
B-7
B-7
OPERATION
• Switch #7 Arc Force Level – Prevents "stubbing"
of the electrode by providing extra output current if
the arc voltage drops below the level required to
sustain the welding arc. High (+65%) and Low
(+12%) factory set levels are selectable which are
good for most stick welding applications.
INTERNAL SET UP CONTROLS
Precision TIG 275 models which have an Advanced
Panel (K1829-1) option installed* have the following
additional control features which are set up using the
DIP Switch (S1) provided on the internal panel of this
option.
ON – Higher for a "crisper" arc, often desired for 6010
type electrodes.
OFF – Lower Arc Force (as shipped) for a "softer" arc
with 7018 or general type electrodes.
Access to this internal panel is obtained by removing
the two screws securing the top corners of the
Precision TIG front control panel and swinging the con-
trol panel down to reveal the panel mounted on the sur-
face of the Precision TIG Control board:
• Switch #8 (NOT CURRENTLY FUNCTIONAL)
TIG WELDING FEATURES
CAUTION
• THE CONTROL BOARDS CONTAIN STATIC SEN-
SITIVE COMPONENTS
The following DIP switch feature selections function
only when the Precision TIG is set to TIG mode (See
Item 3):
• To avoid possible damage to these components
be sure to ground yourself by touching the
machine’s sheet metal while handling or making
settings on the internal control box components.
------------------------------------------------------------------------
PRECISION TIG ADVANCED PANEL
• Switch #1 Preflow/Postflow Time Extension*
(See Item 9)
ON – Doubles the time ranges.
OFF – Standard time ranges (as shipped).
(Internal Panel)
• Switch #2 2-Step Trigger Restart Feature (See
Figure B.3)
^ ON
1 2 3 4 5 6 7
DIP SWITCH (S1)
ON – Restart Enabled (as shipped).
OFF – Restart Disabled.
• Switch #3 4-Step Trigger Restart Feature (See
Figure B.4)
S
F
ON – Restart Enabled.
OFF – Restart Disabled (as shipped)
ON
• Switch #4 (NOT CURRENTLY FUNCTIONAL)
1
2
3
4
5
6
7
8
OFF
• Switch #5 Crater-Fill Level (See Item 7)
DIP SWITCH POSITIONS (FACTORY SETTINGS)
ON - Level is minimum rating of the machine (2A)
OFF – Level (as shipped) is Minimum Output setting
(same as Start level).
STICK WELDING FEATURES
The following DIP switch feature selections function
only when the Precision TIG is set to Stick mode. (See
Item 3):
* The Preflow/Postflow Time doubling feature can also be selected
on Precision TIG 275 models without the Advanced Panel by
accessing the Control board in the control box per above instruc-
tions, then disconnecting the jumper terminals attached to the
jumper plug connected to receptacle J3 of the Control board.
(Refer to Machine Wiring Diagram.)
• Switch #6 Hot Start Level – Provides an extra out-
put "boost" pulse at the arc strike to enhance arc
starting. This is factory set for a level (about 50%
extra) which is usually good for most stick welding
applications
ON – Hot Start level is used (as shipped).
OFF – No Hot Start.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
B-8
B-8
OPERATION
FIGURE B.3
(With DIP Switch #2 OFF)
(With DIP Switch #2 ON, As Shipped)
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
B-9
B-9
OPERATION
FIGURE B.4
(With DIP Switch #3 ON)
(With DIP Switch #3 OFF, As Shipped)
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
B-10
B-10
OPERATION
TIG WELD CYCLE CHART
With PULSE ON
No Pulsing
2 or 4-STEP
Trigger
4-STEP
Trigger
1ST Open
SEE ITEM 12
4-STEP Trigger
Re-closed or
2-STEP Trigger
Opened
4-STEP Trigger
Re-opened
During Upslope Time
or
Closed
after
Downslope Time
SEE ITEM 12
SEE ITEM 12
SEE ITEM 12
When Downslope
Drops Below
Background Setting
MAXIMUM OUTPUT
SETTING
Adjustable 2-Max.A
SEE ITEM 6
CRATER-FILL
LEVEL
Advanced
Panel Select:
Amptrol or Remote
(PEAK) Range
SEE ITEM 6 & 7
Mach. Min.
or
MIN. Setting
(as w/o Panel)
PULSE FREQ.
Adjustable
0.1-20 pps
SEE ITEM 14
% ON TIME
Adjustable
5-95%
MINIMUM OUTPUT
(Start) SETTING
Adjustable 2-50A
SEE ITEM 7
SEE ITEM 7
SEE ITEM 15
BACKGROUND
Adjustable
MIN.Setting -100% Peak
SEE ITEM 16
POSTFLOW
PREFLOW
Fixed 0.5 sec
or x2
UPSLOPE
Fixed<0.5 sec
w/o Amptrol
SEE ITEM 7
DOWNSLOPE
Adjust 0 —10 sec
w/ Advan. Panel
(Fixed 0 sec w/o)
SEE ITEM 17
Adjust 2-60 sec
or x2
SEE ITEM 9
SEE ITEM 9
START TIME
CRATER-FILL TIME
Manual
in 4-Step
Manual in 2/4-Step
w/ Restart Disabled
SEE ITEM 12 & TIG
Welding Features
SEE ITEM 12
USING THE START PEDAL FOOT AMPTROL (K870-1)
SETUP GUIDELINES FOR TIG WELDING
WITH AN AMPTROL
To further enhance reliability of consistently obtaining
this minimum level just after the Amptrol’s start switch
is closed, or just before it opens for crater-fill, the new
K870-1 Start Pedal Foot Amptrol is available. Its
independent start pedal on control pedal provides two-
stage foot action to easily feel start switch closure at
minimum output level for precise arc start and crater
control. Also, an adjustable heel stop helps assure
comfortable foot location.(See Figure B.5)
Both the Hand and Foot Amptrols work in a similar
manner. They are meant to be used for remote current
control for TIG welding using the machine’s 2-Step
trigger mode (See Item 12).
The Amptrol is capable of controlling the output of the
Precision TIG over the range between the level preset
by the Minimum Output control when the Amptrol is at
its inactivated state, and the level preset by the
Maximum Output control when the Amptrol is at fully-
activated state.
Currently available TIG foot pedal controls combine the
arc start switch actuation in the same pedal action with
the output control variable resistance. This technique
provides no independent tactile feel of where the arc
start switch actuates, and at what control level, for con-
sistent TIG starting. Nor does it provide a way for con-
sistent crater-fill control to feel at what decreasing con-
trol pedal position the arc start switch will re-open
causing arc out.
It is important to note that even with the Precision TIG’s
new MicroStartTM Technology, some tungstens may be
difficult to start at the low (2 amps) minimum rating of
the machine. Rather than guessing where to depress
the Amptrol to start the arc reliably, the Minimum
Output control allows presetting the exact level, so
reliable starts, as well as minimum crater-fill levels, can
be consistently obtained at the minimum Amptrol (inac-
tivated ) state. FIGURE B.6 shows Precision TIG setup
for TIG welding with an Amptrol.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
B-11
B-11
OPERATION
The new foot pedal provides such independent action
distinction of precisely where the arc start switch actu-
ates without over-riding minimum control pedal posi-
tion, and precisely where the control pedal has been
returned to minimum position without inadvertently de-
actuating the arc start switch. The result is repeatable
consistency in TIG weld starting and crater-fill for man-
ual process control.
FIGURE B.5
Foot
Rock
Control
Toe
Pressure
Switch
Adjustable
or
Removable
Heel Stop
Using this new foot pedal with the Precision TIG’s new
presettable Minimum Output level, in addition to the
presettable Maximum Output level, further enhances
the starting and crater level consistency as well as the
control resolution of the manually controlled foot pedal.
Maximum Output
Machine Setting
Fully Pressed
Control Pedal
Minimum Output
Machine Setting
At-Rest
Control Pedal
Off
Time
Pressed
Switch Pedal
At-Rest
Switch Pedal
Standard Controls
Setup for TIG Amptrol Welding
FIGURE B.6
Power Switch
ON
Mode Switch
TIG
Polarity Switch
AC Balance
AUTO
or
AC or DC-
Set:
More +
for alum.oxide "Cleaning"
w/o"Spitting" o r"wetting"loss.
+
-
Balanced for equal and current.
More - for higher "Penetration".
Local/Remote
Switch
REMOTE
Maximum Output
Set to desired max.
Amptrol output level.
Minimum Output
Press Display switch
and Set to desired min.
Amptrol (Start/Crater)
output level.
Min. to Max.
Amptrol
Max. to Min.
Amptrol
Postflow
Set as low as required.
Higher for larger
tungsten and current.
Advanced Panel
Controls
Trigger Switch
2-STEP
Pulse Frequency
Pulse Switch
or
4-6 pps is a typical initial setting.
Set for bead shape and travel speed:
Higher for thinner plate and faster travel.
Lower for thicker plate and slower travel.
ON
OFF
% On Time
40-60% is a typical initial setting.
Set for total heat of Peak current:
Lower reduces distortion and burn-thru.
Background Current
40-60% is a typical initial setting.
Downslope
ZERO
For no arc-out delay.
Set as low as will maintain a pulse arc
Min.Output
(Will not drop below
setting.)
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
B-12
B-12
OPERATION
Close the arc start switch. This opens the gas valve
to automatically purge air from the hose and torch,
then shields the arc strike area. After the 0.5 sec-
ond preflow time, the high frequency becomes
available to strike the arc. When the arc strikes the
torch coolant (if used) starts to flow. Also, if welding
DC- TIG, the high frequency shuts off just after the
arc strikes.
MAKING A TIG WELD WITH AN AMPTROL
1. Install welding equipment per Section A-5.
2. Setup controls per Section B-10.
3. Turn on the shielding gas supply, and torch coolant
input supply (if used).
Note: The Precision TIG Under-Cooler (or Water
Solenoid connected to the Cooler receptacle) runs with
the Fan-As-Needed machine cooling fan (See
Maintenance Section D), so the cooler fan and water
pump will also not run continuously in idle, but will run
while welding.
6. Hold the arc start switch closed at minimum Amptrol
Start level (See Section B-10) until an arc is estab-
lished, then increase the output to the desired weld-
ing level and push the torch in the direction of trav-
el.
7. At the end of the weld, decrease the Amptrol output
to the crater-fill level before releasing the arc start
switch to start the Postflow time. Hold the torch gas
shielding over the solidifying weld crater while post-
flow time expires and the gas valve reopens. The
torch coolant (if used) continues to flow for up to 8
minutes after the arc goes out (with the Fan-As-
Needed feature) to assure torch cooling.
4. With the torch held safely away from everything,
close the Arc Start Switch of the Amptrol and set the
gas flow meter. Then open the switch. The welder
is now ready for welding.
5. Position the tungsten electrode at the start of the
weld at a 65° to 75° angle with the horizontal, in the
direction of pushing travel, so that the electrode is
approximately 1/8" (4 mm) above the work piece.
• Repeat steps 5 through 7 to make another weld.
RECOMMENDED ELECTRODE AMPERAGE RANGES - PRECISION TIG 275
SMAW Process
ELECTRODE
Fleetweld 5P, Fleetweld 5P+
Fleetweld 180
Fleetweld 37
Fleetweld 47
Jet-LH MR
Blue Max Stainless
Red Baron Stainless
POLARITY
DC+
3/32"
40 - 70
40 - 80
70 - 95
75 - 95
85 - 110
40 - 80
40 - 70
1/8"
5/32"
75 - 130
55 - 110
100 - 135
100 - 145
110 - 160
75 - 110
60 - 100
90 - 175
105 - 135
145 - 180
135 - 200
130 - 220
95 - 110
90 - 140
DC+
DC+
DC-
DC+
DC+
DC+
Mild steel procedures are based on recommended procedures listed in C2.10 8/94 and the maximum rating of the PRECISION TIG 275
Excaliber 7018 procedures are based on Jet-LH 78 MR
Blue Max procedures are based on C6.1 6/95
Red Baron Procedure are based on ES-503 10/93
GTAW Process
Electrode Polarity
Electrode Tip Preparation
DC-
Sharpened
AC*
Balled
Approximate Argon
Gas Flow Rate
C.F.H. (l/min.)
EWZr
Electrode Type
EWTh-1, EWCe-2
EWTh-2, EWLa-1
EWG
Up to 15 A.
Up to 15 A.
Up to 80 A.
Up to 150 A.
Up to MAX. A.
X
EWTh-1, EWTh-2
EWCe-2, EWLa-1
EWG
EWP
Stainless
Steel
(2-4) 3-8 (2-4)
Electrode Size (in.)
Aluminum
3-8
.010
.020
.040
1/16
3/32
1/8
Up to 15 A.
10 to 15 A.
20 to 30 A.
30 to 80 A.
60 to 130 A.
100 to 180 A.
Up to 15 A.
5 to 20 A.
20 to 60 A.
60 to 120 A.
100 to 180 A.
160 to 250 A.
5-10
5-10
5-10
(3-5) 5-10 (3-5)
(3-5) 5-10 (3-5)
(3-5) 9-13 (4-6)
13-17 (6-8) 11-15 (5-7)
15-23 (7-11) 11-15 (5-7)
Tungsten electrodes are classified as follows by the American Welding Society (AWS):
Pure.........................................EWP...........green
+1% Thoria..............................EWTh-1......yellow
+2% Thoria..............................EWTh-2......red
+2% Ceria................................EWCe-2 .....orange
+1.5% Lanthana ......................EWLa-1......black
+0.15 to 0.40% Zirconia ..........EWZr..........brown
Ceriated Tungsten is now widely accepted as a substitute for 2% Thoriated Tungsten in AC and DC applications.
Balanced Wave, Unbalanced Wave requires derating of the electrode.
*
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
C-1
C-1
ACCESSORIES
• K814 Arc Start Switch
OPTIONAL EQUIPMENT
Needed for TIG welding without an Amptrol. Includes
25’ plug cable, and attaches to torch for convenient
finger control.
FACTORY INSTALLED OPTIONS
The basic Precision TIG 275 machine is factory
equipped with:
• K1831-1 Power Factor Capacitor Kit
Used when welding at higher output currents to
reduce input current and help keep electricity costs
to a minimum.
• A 3/8" Adapter (S20403-4) for air cooled torch con-
nection of a PTA-9 or PTA-17.
• Magnum® PTA and PTW Series Torches
FIELD INSTALLED OPTIONS
All Air Cooled or Water-Cooled Magnum® TIG
Torches may be used with the PRECISION TIG 275.
Connection adapters are only required for Air-Cooled
Torches (Refer to Diagrams on A-7):
The following Options/Accessories are available for the
Precision TIG 275 and are installed per instructions in
this manual and / or provided in the package:
K2166-1 7/8” Torch Connector for PTA-26 (one
piece)
• K1829-1 Precision TIG Advanced Control Panel
Provides 2/4-step trigger with adjustable Pulser con-
trols and Down slope timer for TIG welding. Also
includes adjustable Hot Start and Arc Force internal
panel controls for Stick welding, and other user
selectable features.
K2166-2 1/2” stud Connector for PTA Torch (two-
piece).
K2166-3 3/8” TIG Torch Connector for PTA-9,-17
(one piece). (Included as S20403-4 with Precision
TIG models.)
• K1828-1 Under-Cooler Cart
Includes a "cooler-in-a-drawer" with hoses and a
lockable storage drawer on a dual bottle undercar-
riage (see below).
• 3100211 Harris Argon Flow Regulator (Includes 10’
hose.)
• K1869-1 Undercarriage
• K2150-1 Work Lead Assembly
15ft. 2/0 cable with 1/2" stud lug and work clamp.
Includes a dual bottle rack with chain and an under-
carriage with 5" front casters,10" rear wheels and a
handle.
• K1830-1 Water Solenoid Kit
Provides for stopping flow of external water supply.
Connects to coolant inlet and cooler receptacle of
Precision TIG.
(Can not be used with a water cooler.)
• K870 Foot Amptrol
Single pedal foot activation of arc start switch and
output control, with 25’ plug cable.
• K870-1 Start Pedal Foot Amptrol
Independent start pedal on control pedal provides
two-stage foot action to easily feel start switch clo-
sure at minimum output level for enhanced arc start
and crater-fill control. Provided with adjustable, or
removable, heel stop and 25’ plug cable.(Refer to
Figure B.5)
• K963-3 Hand Amptrol
Fastens to torch for convenient thumb activation of
arc start switch and output control, with 25’ plug
cable:
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
D-1
D-1
MAINTENANCE
SAFETY PRECAUTIONS
OVERLOAD PROTECTION
FAN-AS-NEEDED (F.A.N.)
WARNING
The Precision TIG 275 has the F.A.N. circuit feature,
which means the cooling fan will operate only while
welding; then for about 8 minutes after welding has
stopped to assure proper machine cooling. This helps
reduce the amount of dust and dirt drawn into the
machine with the cooling air. The cooling fan will oper-
ate briefly when the machine power is initially turned
on, and continuously while the yellow Thermal
Shutdown Light is lit (see Thermostatic Protection).
ELECTRIC SHOCK can kill.
• Only qualified personnel should
perform this maintenance.
• Turn the input power OFF at the
disconnect switch or fuse box
before working on this
equipment.
• Do not touch electrically hot
parts.
THERMOSTATIC PROTECTION
This welder has thermostatic protection from excessive
duty cycles, overloads, loss of cooling, and excessive
ambient temperatures. When the welder is subjected
to an overload, or inadequate cooling, the primary coil
thermostat and/or secondary coil thermostat will open.
This condition will be indicated by the illumination of
the yellow Thermal Shutdown Light on the front panel
(see Item 10 in Section B). The fan will continue to run
to cool the power source. Postflow occurs when TIG
welding is shut down, but no welding is possible until
the machine is allowed to cool and the yellow Thermal
Shutdown Light goes out.
WARNING
To avoid receiving a high frequency shock, keep the
TIG torch and cables in good condition.
ROUTINE AND PERIODIC MAINTENANCE
Very little routine maintenance is necessary to keep
your Precision TIG 275 running in top condition. No
specific schedule can be set for performing the follow-
ing items; factors such as hours of usage and machine
environment should be considered when establishing
a maintenance schedule.
NO ARC PROTECTION
The machine outputs (Background / OCV, gas and HF)
will be shutdown, if the trigger is closed without weld-
ing for 15 seconds to protect the Background resistor
from overheating with F.A.N. cooling off, as well as to
conserve on gas waste.
• Periodically blow out dust and dirt which may accu-
mulate within the welder using an air stream.
• Inspect welder output and control cables for fraying,
cuts, and bare spots.
AUXILIARY POWER CIRCUIT BREAKER
• Inspect the spark gap at regular intervals to maintain
the recommended spacing. See the Service
Procedures (See Service Procedures in this
Section) for complete information on spark gap set-
tings.
The 115vac auxiliary circuits and rear receptacle (see
Section A Auxiliary Power Connections) are protected
from overloads by a 15 amp circuit breaker, located
above the receptacle. If the breaker trips its button
pops out exposing a red ring. When the circuit breaker
cools the button can be reset by pressing it back in.
Note: When the breaker trips not only will the recepta-
cle’s auxiliary and cooler power be interrupted, but so
will the power to the shielding gas solenoid and
machine cooling fan.
• The fan motor has sealed ball bearings which
require no maintenance.
Overload Protection
The Export models also include a 5 amp circuit break-
er, located on the opposite side of the upper case back,
for protection of the 220vac Schuko type cooler recep-
tacle.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
D-2
D-2
MAINTENANCE
FIGURE C.1 SPARK GAP
SERVICE PROCEDURES
Operation of the Precision TIG should be trouble-free
for the life of the machine. Should a malfunction occur,
however, the following procedures will be useful to
trained service personnel with experience in repairing
arc welding equipment:
.015 Spark Gap
COMPONENT ACCESS
Note: In highly dirty environments where there is an
abundance of conductive contaminants, use a low
pressure air stream or a firm piece of paper to clean
out the spark gap. Do not disturb the factory gap set-
ting.
The following components are accessible for routine
set up and periodic service without requiring removal
of the case sides or roof:
• Input Reconnect Panel (refer Section A) is located
behind a removable panel on the rear of the left case
side. Remove the two screws (with a screwdriver or
a 3/8"/ 9.5mm hex driver) on the bottom corners of
this panel to remove it.
To check the spark gap:
1. Turn the input power off per above.
2. Remove the access panel on the right case side
(See Component Access).
3. Check the spark gap spacing with a feeler gauge.
• Control Box components and PC Boards (refer
Section B-6) are located behind the front control
panel. Remove the two screws (with a screwdriver or
a 3/8"/ 9.5mm hex driver) on the top corners of this
panel to swing it down.
If adjustment is required:
1. Adjust the gap by loosening the Allen head screw
on one of the aluminum blocks, reset the gap and
tighten the screw in the new position.
• Hi-Freq. Spark Gap assembly (refer Spark Gap
Adjustment) is located behind a removable panel on
the rear of the right case side, under the torch box.
Remove the screw (with a screwdriver or a 3/8"/
9.5mm hex driver) on the bottom center of this panel
to remove it.
If spark gap is correct:
1. Reinstall the access panel on the right case side.
UNDER-COOLER SERVICE
The required maintenance and service instructions for
the Under-Cooler are provided in the operator’s manu-
al (IM723) provided with the Under-Cooler Cart.
SPARK GAP ADJUSTMENT
The spark gap is set at the factory to a gap of 0.015
inches (0.4 mm) See Figure C.1. This setting is ade-
quate for most applications. Where less high frequen-
cy is desired, the setting can be reduced to 0.008 inch-
es (0.2 mm).
WARNING
Use extreme caution when working with circuit of
the high frequency. The high voltages developed
can be lethal. Turn the input power off using the
disconnect switch or fuse box before working
inside the machine. This is particularly important
when working on the secondary circuit of the high
voltage transformer (T3) because the output volt-
age is dangerously high.
------------------------------------------------------------------------
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
E-1
E-1
TROUBLESHOOTING
HOW TO USE TROUBLESHOOTING GUIDE
WARNING
Service and Repair should only be performed by 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 malfunctions.
Simply follow the three-step procedure listed below.
This column provides a course of action for the
Possible Cause, generally it states to contact your
local Lincoln Authorized Field Service Facility.
Step 1. LOCATE PROBLEM (SYMPTOM).
If you do not understand or are unable to perform the
Recommended Course of Action safely, contact your
local Lincoln Authorized Field Service Facility.
Look under the column labeled “PROBLEM (SYMP-
TOMS)”. This column describes possible symptoms
that the machine may exhibit. Find the listing that best
describes the symptom that the machine is exhibiting.
Step 2. POSSIBLE CAUSE.
The second column labeled “POSSIBLE CAUSE” lists
the obvious external possibilities that may contribute to
the machine symptom.
Step 3. RECOMMENDED COURSE OF ACTION
CAUTION
DO NOT use a volt-ohm meter to measure output voltages in TIG mode. The
High Frequency Arc Starter voltage can damage the meter.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your Local
Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
E-2
E-2
TROUBLESHOOTING
Observe all Safety Guidelines detailed throughout this manual
PROBLEMS
(SYMPTOMS)
POSSIBLE
CAUSE
RECOMMENDED
COURSE OF ACTION
OUTPUT PROBLEMS
Thermal light comes on
1. Thermal shut down. Dirt and dust
may have clogged the cooling
channels inside machine; air
intake and exhaust louvers may
be blocked; welding application
may exceed recommended duty
cycle. Wait until machine cool
down and thermal light goes out.
Blow out machine with clean, dry
low pressure air; check air intake
and louvers; stay within recom-
mended duty cycle.
2. Bad thermostat or its connections
Meter doesn’t light up
1. Losing AC supply to Control PC
board
2. Loosing input to machine
3. Faulty Control PC board
If all recommended possible areas
of misadjustment have been
checked and the problem persists,
Has output in
Stick mode
No gas & no hi-freq 1. Faulty trigger or hand/foot Amptrol
or connections.
Contact
your
local
Lincoln
Authorized Field Service Facility.
but no output
in Tig mode
2. Faulty Protection PC board or
bad connection to Control PC
board
3. Losing trigger supply to Control
PC board
Gas & hi-freq are o.k. 1. Faulty Control PC board
No output in both Stick and Tig
modes
1. Bad connection at P4 of Control
PC board
2. Faulty Control PC board
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your Local
Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
E-3
E-3
TROUBLESHOOTING
Observe all Safety Guidelines detailed throughout this manual
PROBLEMS
(SYMPTOMS)
POSSIBLE
CAUSE
RECOMMENDED
COURSE OF ACTION
METER PROBLEMS
Meter does not light up
1. Bad meter or its connection
2. Bad connection at P8 of Control
PC board
If all recommended possible areas
of misadjustment have been
checked and the problem persists,
3. Faulty Control PC board
Contact
your
local
Lincoln
Authorized Field Service Facility.
Meter does not display V (Volt) or
Min A (Minimum current)
1. Bad Display switch or its connec-
tion
2. Bad connection at P9 of Control
PC board
GAS PROBLEMS
No gas
1. Circuit breaker CB1 open. Press
CB1 in to reset
2. Bad connection at P12 of Control
PC board
3. Faulty gas solenoid valve SV1 or
its connection
4. Faulty Control PC board
No control on post flow time
1. Faulty potentiometer R3 or its
connection
If all recommended possible areas
of misadjustment have been
checked and the problem persists,
2. Bad connection at P9 of Control
PC board
Contact
your
local
Lincoln
Pre flow & Post flow time too long
1. If an Advanced Control PC board
was installed, check setting of
DIP switch on that board
Authorized Field Service Facility.
2. Missing plug P3 on Control board
or bad connection at P3 when an
Advanced Control PC board is not
present
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your Local
Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
E-4
E-4
TROUBLESHOOTING
Observe all Safety Guidelines detailed throughout this manual
PROBLEMS
(SYMPTOMS)
POSSIBLE
CAUSE
RECOMMENDED
COURSE OF ACTION
HI-FREQ PROBLEMS
No hi-freq
1. Circuit breaker CB1 open
2. Bad connection at P12 of Control
PC board
3. Spark gaps shorted
4. Faulty Control PC board
Hi-freq intensity too weak
1. Dirty spark gap or improper gap
setting
2. Faulty Arc Starter assembly
Hi-freq on continuously in DC Tig
1. Bad connection at P11 of Control
PC board
2. Micro-switch S2A is not engaged &
disengaged properly when switch-
ing between DC & AC polarity.
(S2A locates on the Polarity
switch)
If all recommended possible areas
of misadjustment have been
checked and the problem persists,
3. Faulty Control PC board
Contact
your
local
Lincoln
Authorized Field Service Facility.
Hi-freq shuts off after starting in AC 1. Micro-switch S2A is not engaged &
Tig
disengaged properly when switch-
ing between DC & AC polarity.
(S2A locates on the Polarity
switch)
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your Local
Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
E-5
E-5
TROUBLESHOOTING
Observe all Safety Guidelines detailed throughout this manual
PROBLEMS
(SYMPTOMS)
POSSIBLE
CAUSE
RECOMMENDED
COURSE OF ACTION
PRESET & OUTPUT CONTROL PROBLEMS
Meter does not display preset
1. Faulty potentiometer R1 or its con-
nection
2. Bad connection at P9 of Control
PC board
3. Faulty Advanced Control PC board
( if present ) or its connection to
the main Control PC board
4. Missing plug P3 on Control board
or bad connection at P3 when an
Advanced Control PC board is not
present
High output current in both DC & AC 1. Bad connection at P6 of Control
polarities regardless of preset
PC board
2. Bad shunt connection
3. Faulty Control PC board
4. Faulty SCR bridge
If all recommended possible areas
of misadjustment have been
checked and the problem persists,
Contact
your
local
Lincoln
High output current in DC polarity 1. Shorted free wheeling diode D1
Authorized Field Service Facility.
regardless of preset, o.k. in AC polar-
ity
In 2-step Tig, output stays on for 1. Bad 2/4 step switch or its connec-
more than downslope time after trig-
ger open (machine with Advanced
Control panel only)
tion
2. Bad connection at P1 of Advanced
Control PC board
Output stays on after releasing 1. Downslope is not set at min.
hand/foot Amptrol (machine with
Advanced Control panel only)
2. Bad Downslope potentiometer
R12 or its connection
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your Local
Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
E-6
E-6
TROUBLESHOOTING
Observe all Safety Guidelines detailed throughout this manual
PROBLEMS
(SYMPTOMS)
POSSIBLE
CAUSE
RECOMMENDED
COURSE OF ACTION
STICK WELDING PROBLEMS
Stick electrode "blast off" when arc 1. Current may be set too high for
is struck
electrode size
2. (Machine with Advanced Control If all recommended possible areas
PC board only) Hot Start level set of misadjustment have been
too high
checked and the problem persists,
Contact your local Lincoln
Stick electrode "sticks" in the weld
puddle
1. Current may be set too low for Authorized Field Service Facility.
electrode size
2. (Machine with Advanced Control
PC board only) Arc Force level set
too low
TIG WELDING PROBLEMS
Poor starting in DC polarity
1. Input line may be too low
2. Bad connection at P11 of Control
PC board
3. Bad Background rectifier, back-
ground resistor R7, or background
diode D2
Arc "flutters" in DC polarity, o.k. in
AC polarity
1. Tungsten not "sharp"
2. Bad free wheeling diode D1 or its
connection
If all recommended possible areas
of misadjustment have been
Arc "flutters" in both DC & AC polari- 1. Tungsten electrode may be too checked and the problem persists,
ties large in diameter for the current Contact your local Lincoln
Authorized Field Service Facility.
setting
2. Gas shielding may be insufficient.
3. Contaminated gas or leaks in the
gas line, torch, or connections
4. Helium blend is used as a shield-
ing gas
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your Local
Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
E-7
E-7
TROUBLESHOOTING
Observe all Safety Guidelines detailed throughout this manual
PROBLEMS
(SYMPTOMS)
POSSIBLE
CAUSE
RECOMMENDED
COURSE OF ACTION
TIG PROBLEMS
Arc "pulsates" in AC polarity, DC 1.Micro switch S2A on polarity switch
polarity is o.k.
does not open in AC polarity
Black area along weld bead
1. Oily or organic contamination from
work piece
2. Tungsten electrode may be conta-
minated
3. Leaks in gas line, torch, or con-
nections
Output quits momentarily; gas flow 1. May be caused by hi-freq interfer-
and hi-freq are also interrupted
ence. Check that machine is
grounded properly. Surrounding
machines that generate hi-freq
also should be properly grounded.
2. Ground connection of Protection
PC board may has become loose
If all recommended possible areas
of misadjustment have been
checked and the problem persists,
3. Ground
connection
of
Bypass/Stabilizer PC board may
has become loose.
Contact
your
local
Lincoln
Authorized Field Service Facility.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your Local
Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
F-1
F-1
WIRING DIAGRAM
3 A 2 3
2 6 2
6 6 2
5 6 2
A 6 6 2
A 5 6 2
N E G
6 8 2
3 5 2
1 2 2
2 2 2
W
R
2 5 2
G E N
1 A 2 3
2 3 3 A
8
2 3
2 3 9
2 3 1 E
A 0 2 2
6
2 3
O N A L ( ) O P T I
O I N T G I T O P
B C
P
4 B 3 0
4 0 1 D
5 3 3
3 1 3
8 1 3
A 6 1 3
7 0 4
4 3 3
3 3 3
5 1 3
B 6 1 3
C 6 1 3
1 2 3
4 1 0
4 0
4 0
2 1 3
1 1 3
A 1 1 3
9
8
A 6 1 3
B 6 1 3
4 0 4
6 1 3
7 1 3
4 0 6
4 0
1 D 4 0
0 2 3
4 1 3
5
2 3 3
C 3 1 3
B 1 0 4
A 1 0 4
1 0 4
2 2 3
A 1 1 3
4 0 3
4 0 2
3 3 1
C 6 1 3
1 B 4 0
9 1 3
1 1 4
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
F-2
F-2
DIMENSION PRINT
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
NOTES
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
NOTES
PRECISION TIG 275
Download from Www.Somanuals.com. All Manuals Search And Download.
l
l
Do not touch electrically live parts or
electrode with skin or wet clothing.
Insulate yourself from work and
ground.
l
l
Keep flammable materials away.
l
l
Wear eye, ear and body protection.
WARNING
Spanish
l
No toque las partes o los electrodos
bajo carga con la piel o ropa moja-
da.
Mantenga el material combustible
fuera del área de trabajo.
Protéjase los ojos, los oídos y el
cuerpo.
AVISO DE
PRECAUCION
French
l
l
Aislese del trabajo y de la tierra.
Ne laissez ni la peau ni des vête-
ments mouillés entrer en contact
avec des pièces sous tension.
l
l
Gardez à l’écart de tout matériel
inflammable.
l
l
Protégez vos yeux, vos oreilles et
votre corps.
ATTENTION
l
l
Isolez-vous du travail et de la terre.
German
Berühren Sie keine stromführenden
Teile oder Elektroden mit Ihrem
Körper oder feuchter Kleidung!
Isolieren Sie sich von den
Entfernen Sie brennbarres Material!
Tragen Sie Augen-, Ohren- und Kör-
perschutz!
WARNUNG
l
l
Elektroden und dem Erdboden!
Portuguese
Não toque partes elétricas e elec-
trodos com a pele ou roupa molha-
da.
l
Mantenha inflamáveis bem guarda-
dos.
l
Use proteção para a vista, ouvido e
corpo.
ATENÇÃO
l
Isole-se da peça e terra.
Japanese
Chinese
Korean
Arabic
READ AND UNDERSTAND THE MANUFACTURER’S INSTRUCTION FOR THIS EQUIPMENT AND THE CONSUMABLES TO
BE USED AND FOLLOW YOUR EMPLOYER’S SAFETY PRACTICES.
SE RECOMIENDA LEER Y ENTENDER LAS INSTRUCCIONES DEL FABRICANTE PARA EL USO DE ESTE EQUIPO Y LOS
CONSUMIBLES QUE VA A UTILIZAR, SIGA LAS MEDIDAS DE SEGURIDAD DE SU SUPERVISOR.
LISEZ ET COMPRENEZ LES INSTRUCTIONS DU FABRICANT EN CE QUI REGARDE CET EQUIPMENT ET LES PRODUITS A
ETRE EMPLOYES ET SUIVEZ LES PROCEDURES DE SECURITE DE VOTRE EMPLOYEUR.
LESEN SIE UND BEFOLGEN SIE DIE BETRIEBSANLEITUNG DER ANLAGE UND DEN ELEKTRODENEINSATZ DES HER-
STELLERS. DIE UNFALLVERHÜTUNGSVORSCHRIFTEN DES ARBEITGEBERS SIND EBENFALLS ZU BEACHTEN.
Download from Www.Somanuals.com. All Manuals Search And Download.
l
l
Keep your head out of fumes.
Use ventilation or exhaust to
remove fumes from breathing zone.
l
l
Turn power off before servicing.
l
l
Do not operate with panel open or
guards off.
WARNING
Spanish
l
l
Los humos fuera de la zona de res-
piración.
Mantenga la cabeza fuera de los
humos. Utilice ventilación o
aspiración para gases.
Desconectar el cable de ali-
mentación de poder de la máquina
antes de iniciar cualquier servicio.
No operar con panel abierto o
guardas quitadas.
AVISO DE
PRECAUCION
French
l
l
Débranchez le courant avant l’entre-
tien.
l
l
N’opérez pas avec les panneaux
ouverts ou avec les dispositifs de
protection enlevés.
l
l
Gardez la tête à l’écart des fumées.
Utilisez un ventilateur ou un aspira-
teur pour ôter les fumées des zones
de travail.
ATTENTION
German
Strom vor Wartungsarbeiten
abschalten! (Netzstrom völlig öff-
nen; Maschine anhalten!)
Anlage nie ohne Schutzgehäuse
oder Innenschutzverkleidung in
Betrieb setzen!
l
l
Vermeiden Sie das Einatmen von
Schweibrauch!
Sorgen Sie für gute Be- und
Entlüftung des Arbeitsplatzes!
WARNUNG
Portuguese
l
l
Não opere com as tampas removidas.
Desligue a corrente antes de fazer
serviço.
l
l
Mantenha-se afastado das partes
moventes.
Não opere com os paineis abertos
ou guardas removidas.
l
l
Mantenha seu rosto da fumaça.
Use ventilação e exhaustão para
remover fumo da zona respiratória.
ATENÇÃO
l
Não toque as partes elétricas nuas.
Japanese
Chinese
Korean
Arabic
LEIA E COMPREENDA AS INSTRUÇÕES DO FABRICANTE PARA ESTE EQUIPAMENTO E AS PARTES DE USO, E SIGA AS
PRÁTICAS DE SEGURANÇA DO EMPREGADOR.
Download from Www.Somanuals.com. All Manuals Search And Download.
• 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
Download from Www.Somanuals.com. All Manuals Search And Download.
|