90MA/MU
Single-Package Marine Cooling Units
Installation, Operation and Service Instructions
SAFETY CONSIDERATIONS
The 90MA/MU Units are designed to provide safe and
reliable service when operated within design specifications.
However, due to system pressures, electrical components,
and equipment location, some aspects of installation,
operation and servicing of this equipment can be hazardous.
Only trained, qualified installers and service technicians
should install, operate, and service this equipment.
When working on the equipment, observe all precautions
on tags or labels attached to the unit. Safety notes in the
literature, and any other safety precautions that apply.
• Follow all safety codes.
CONTENTS
Page
SAFETY CONSIDERATIONS........................................1
GENERAL .....................................................................1
INSTALLATION.............................................................1
Step 1- Inspect Unit .......................................................1
Step 2 - Protect Unit from Damage................................1
Step 3 - Provide Unit Support ........................................1
Step 4 - Rig and Place Unit............................................8
Step 5 - Install Accessory Plenum (If Supplied) ............8
Step 6 – Check Fan Shaft and Wheel Alignment...........9
Step 7 - Install Ventilation Ductwork (If Required)..........9
Step 8 - Check Return-Air Filters ...................................9
Step 9 - Check Compressor Spring Mounts
• Wear safety glasses and work gloves.
(*08 & *12)................................................................9
Step 10 - Make Condenser Connections .......................9
Step 11 - Install Unit Drain Line ...................................11
Step 12 - Make Electrical Connections ........................12
OPERATION................................................................12
To Start Unit.................................................................12
To Shut Down Unit.......................................................12
Service Valves .............................................................12
SERVICE .....................................................................13
Return-Air Grill Removal ..............................................13
Access Panel Removal ................................................13
Evaporator Fan Adjustment .........................................13
Lubrication ...................................................................13
Return-Air Filters..........................................................13
Condensate Drains ......................................................13
Evaporator Coil ............................................................14
Water Regulating Valve ...............................................14
Condenser ...................................................................14
Charging the System....................................................15
Evaporator Fan Motor Removal...................................15
Pressure Relief Device.................................................15
Crankcase Heater........................................................15
Cycle-LOCTM Protection Device...................................15
Discharge And Suction Pressure Switches ..................16
Oil Charge....................................................................16
WIRING SCHEMATIC - *04/*06...................................17
COMPONENT ARRANGEMENT - *04/*06..................18
WIRING SCHEMATIC - *08/*12...................................19
COMPONENT ARRANGEMENT - *08/*12..................20
UNIT SUPPORT DRAWINGS .....................................21
• Use care in handling, rigging, and placing bulky
equipment.
WARNING
Never reach into unit while fan is running. Lock
open and tag power disconnect before working
on a fan. Remove the fuses and take them with
you after noting this on tag.
Check assembly and component weight to be
sure rigging equipment can handle them safely.
Note also any specific rigging instructions.
When steam cleaning coils, be sure area is
clear of personnel.
GENERAL
The 90MA/MU water cooled single-package cooling units
are designed to provide air conditioning aboard marine
vessels. The 90MA units are fitted with a water cooled
condenser and are factory charged, wired and piped. The
90MU units are similar to the 90MA except they are
configured for use of a remote mounted condenser.
An accessory discharge plenum may be installed to
provide free-blow into the conditioned space. Also, an
optional electric heater may be specified to provide comfort
heating.
INSTALLATION
Step 1 - Inspect Unit - Check unit against shipping order.
Inspect carefully for concealed shipping damage. If shipment
is damaged or incomplete, file claim with transportation
company and advise Carrier Transicold immediately.
Step 2 - Protect Unit from Damage - To maintain warranty,
protect unit against adverse weather, theft, or vandalism on
job site.
Step 3 - Provide Unit Support - Refer to Figure 2 and
Tables 1A/B/C/2A/B/C for unit size and weight. If desired,
construct a frame of I-beams or angle iron that adequately
supports unit. See unit support drawings contained in this
document.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations
Printed in U.S.A. 90MA-3SI SUPERCEDES FORM 62-02971-00 09-2009
Pg 1
TABLE 1B - 90MA/MU PHYSICAL DATA – R-407C , ENGLISH UNITS (See Table 2B for SI units)
BASE UNIT (90MA/MU)
NOMINAL CAPACITY
REFRIGERANT
UNITS
Tons
404
3
406
5
408
7.5
412
10
R-407C
OPERATING WEIGHT
Base unit 90MA
Pounds
Pounds
Pounds
390
330
25
427
360
25
895
835
50
950
890
50
Base Unit 90MU
Discharge Plenum
COMPRESSOR TYPE
Qty Cylinders
Qty Unloading Cylinders
Qty Capacity Steps
DISCHARGE PRESSURE SWITCH
Opens (90MA)
Scroll
N/
N/
Semi-Hermetic, Recip
4
0
1
6
2
2
1
PSIG
PSIG
PSIG
PSIG
395+/-10
295+/-10
426+/-7
Closes (90MA)
Opens (90MU)
Closes (90MU)
320+/-20
SUCTION PRESSURE SWITCH
Opens
PSIG
PSIG
27+/-4
67+/-4
Closes
REFRIGERANT
Typ
R-407C
Qty (90MA ONLY))
CONDENSER (90MA ONLY)
Number...Type
Pounds
Gallons
3.1
5.3
11.2
10.0
1…Tube in Tube
0.86
Water Volume
0.39
2.42
EVAPORATOR AIR FAN
Nominal Flow
Adjustable, Belt Driven Centrifugal: 1750 RPM Motor @ 60hz
CFM
RPM
RPM
Inches
Inches
1200
2000
3000
4000
Standard Speed Range
Maximum Allowable Speed
Belt Qty/Pulley Pitch Diameter
Motor Pulley Pitch Diameter Range
Motor Nominal Rating (@ 60Hz)…Frame Size
Standard
647-914
647-915
487-690
591-838
1250
1 / 6.4
1 / 6.4
1 / 8.5
1 / 7.0
2.4 to 3.4 inches
HP
HP
HP
1/3…56
3/4…56
N/
3/4…56
1…56
N/
1…56
2…56
3…56
2…56
3…56
N/
Alternate (SeeNote 1)
Alternate (See Note 1)
EVAPORATOR COIL
Tube
3/8 OD, Copper Tubes, Aluminum Fin
Prime
Qty Rows…Fin Spacing
Face Area
Fins/Inch
Sq Ft
2…14.4
5
3…14.4
5
3…12.5
7.3
8.5
RETURN AIR FILTERS
Qty…Size
Factory Supplied, Cleanable
2…16 x 25 x 1 4…16 x 20 x 1
Inches
CONDENSER CONNECTIONS (90MA ONLY)
Water Inlet (bottom)
Water Outler (top)
Inches FPT
Inches FPT
1/2
1/2
3/4
3/4
1
1
1
1
Maximum Working Pressure (Refrigerant Side) PSIG
400
3/4
CONDENSATE DRAIN CONNECTIONS
Inches FPT
ACCESSORY ELECTRIC HEAT
Capacity @ 460 volts
Watts
Watts
5.25
4.03
1
17.5
13.4
2
Capacity @ 400 volts
Number of Electric Heat Stages
LEGEND
FPT = Female Pipe Thread MPT = Male Pipe Thread ODF = Outside Diameter Female
NOTES:
1. Motors other than those furnished with unit must be purchased separately. Contact your Carrier Marine representative
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations
Printed in U.S.A. 90MA-3SI SUPERCEDES FORM 62-02971-00 09-2009
Pg 3
TABLE 1C - 90MA/MU PHYSICAL DATA – R-404A , ENGLISH UNITS (See Table 2C for SI units)
BASE UNIT (90MA/MU)
NOMINAL CAPACITY
REFRIGERANT
UNITS
Tons
504
3
506
5
508
7.5
512
10
R-
OPERATING WEIGHT
Base unit 90MA
Pounds
Pounds
Pounds
390
330
25
427
360
25
895
835
50
950
890
50
Base Unit 90MU
Discharge Plenum
COMPRESSOR TYPE
Qty Cylinders
Qty Unloading Cylinders
Qty Capacity Steps
DISCHARGE PRESSURE SWITCH
Opens (90MA)
Scroll
N/
N/
Semi-Hermetic, Recip
4
0
1
6
2
2
1
PSIG
PSIG
PSIG
PSIG
395+/-10
295+/-10
426+/-7
Closes (90MA)
Opens (90MU)
Closes (90MU)
320+/-20
SUCTION PRESSURE SWITCH
Opens
PSIG
PSIG
27+/-4
67+/-4
Closes
REFRIGERANT
Typ
R-
Qty (90MA ONLY))
CONDENSER (90MA ONLY)
Number...Type
Pounds
Gallons
3.1
5.3
11.2
10.0
1…Tube in Tube
0.86
Water Volume
0.39
2.42
EVAPORATOR AIR FAN
Nominal Flow
Adjustable, Belt Driven Centrifugal: 1750 RPM Motor @ 60hz
CFM
RPM
RPM
Inches
Inches
1200
2000
3000
4000
Standard Speed Range
Maximum Allowable Speed
Belt Qty/Pulley Pitch Diameter
Motor Pulley Pitch Diameter Range
Motor Nominal Rating (@ 60Hz)…Frame Size
Standard
647-915
647-915
487-690
591-838
1250
1 / 6.4
1 / 6.4
1 / 8.5
1 / 7.0
2.4 to 3.4 inches
HP
HP
HP
1/3…56
3/4…56
N/
3/4…56
1…56
N/
1…56
2…56
3…56
2…56
3…56
N/
Alternate (SeeNote 1)
Alternate (See Note 1)
EVAPORATOR COIL
Tube
3/8 OD, Copper Tubes, Aluminum Fin
Prime
Qty Rows…Fin Spacing
Face Area
Fins/Inch
Sq Ft
2…14.4
5
3…14.4
5
3…12.5
7.3
8.5
RETURN AIR FILTERS
Qty…Size
Factory Supplied, Cleanable
2…16 x 25 x 1 4…16 x 20 x 1
Inches
CONDENSER CONNECTIONS (90MA ONLY)
Water Inlet (bottom)
Water Outler (top)
Inches FPT
Inches FPT
1/2
1/2
3/4
3/4
1
1
1
1
Maximum Working Pressure (Refrigerant Side) PSIG
400
3/4
CONDENSATE DRAIN CONNECTIONS
Inches FPT
ACCESSORY ELECTRIC HEAT
Capacity @ 460 volts
Watts
Watts
5.25
4.03
1
17.5
13.4
2
Capacity @ 400 volts
Number of Electric Heat Stages
LEGEND
FPT = Female Pipe Thread MPT = Male Pipe Thread ODF = Outside Diameter Female
NOTES:
1. Motors other than those furnished with unit must be purchased separately. Contact your Carrier Marine representative
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations
Printed in U.S.A. 90MA-3SI SUPERCEDES FORM 62-02971-00 09-2009
Pg 4
TABLE 2A - 90MA/MU PHYSICAL DATA – R-134A , SI UNITS
BASE UNIT (90MA/MU)
NOMINAL CAPACITY
REFRIGERANT
UNITS
kW
308
19.3
312
28.1
R-
OPERATING WEIGHT
Base unit 90MA
kg
kg
kg
406
N/
22.7
431
N/
22.7
Base Unit 90MU
Discharge Plenum
COMPRESSOR TYPE
Qty Cylinders
Qty Unloading Cylinders
Qty Capacity Steps
DISCHARGE PRESSURE SWITCH
Opens (90MA)
Semi-Hermetic, Recip
4
0
1
6
2
2
kPa
kPa
kPa
kPa
2310+/-69
1620+/-138
Closes (90MA)
Opens (90MU)
Closes (90MU)
N/
N/
SUCTION PRESSURE SWITCH
Opens
kPa
kPa
48+/-12
152+/-35
Closes
REFRIGERANT
Typ
R-
Qty (90MA ONLY))
kg
5.1
4.5
CONDENSER (90MA ONLY)
Number...Type
1…Tube in Tube
9.2
Water Volume
Liter
EVAPORATOR AIR FAN
Nominal Flow
Adjustable, Belt Driven Centrifugal:1750 RPM Motor @60hz
m3/hr
RPM
RPM
cm
4245
5660
Standard Speed Range
Maximum Allowable Speed
Belt Qty/Pulley Pitch Diameter
Motor Pulley Pitch Diameter Range
Motor Nominal Rating (@ 60Hz)…Frame Size
Standard
402-570
488-692
1250
1 / 21.6
1 / 17.8
cm
6.1 to 8.6 cm
kW
kW
kW
0.75…56
1.5…56
2.2…56
1.5…56
2.2…56
N/
Alternate (SeeNote 1)
Alternate (See Note 1)
EVAPORATOR COIL
Tube
3/8 OD, Copper Tubes, Aluminum Fin
Prime
3…4.9
Qty Rows…Fin Spacing
Face Area
Fins/cm
m2
0.68
0.79
RETURN AIR FILTERS
Qty…Size
Factory Supplied, Cleanable
cm
4…40.6 x 50.8 x 2.5
CONDENSER CONNECTIONS (90MA ONLY)
Water Inlet (bottom)
Water Outler (top)
Maximum Working Pressure (Refrigerant Side)
CONDENSATE DRAIN CONNECTIONS
ACCESSORY ELECTRIC HEAT
Capacity @ 460 volts
Capacity @ 400 volts
Number of Electric Heat Stages
Inches FPT
Inches FPT
kPa
1
1
1
1
2758
3/4
Inches FPT
kW
kW
17.5
13.4
2
LEGEND
FPT = Female Pipe Thread MPT = Male Pipe Thread ODF = Outside Diameter Female
NOTES:
1. Motors other than those furnished with unit must be purchased separately. Contact your Carrier Marine representative
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations
Printed in U.S.A. 90MA-3SI SUPERCEDES FORM 62-02971-00 09-2009
Pg 5
TABLE 2B - 90MA/MU PHYSICAL DATA – R-407C , SI UNITS
BASE UNIT (90MA/MU)
NOMINAL CAPACITY
REFRIGERANT
UNITS
kW
404
10.5
406
17.6
408
26.4
412
35.1
R-407C
OPERATING WEIGHT
Base unit 90MA
kg
kg
kg
177
150
11.3
194
163
11.3
406
379
22.7
431
404
22.7
Base Unit 90MU
Discharge Plenum
COMPRESSOR TYPE
Qty Cylinders
Qty Unloading Cylinders
Qty Capacity Steps
DISCHARGE PRESSURE SWITCH
Opens (90MA)
Scroll
N/
N/
Semi-Hermetic, Recip
4
0
1
6
2
2
1
kPa
kPa
kPa
kPa
2725+/-69
2034+/-138
2937+/-48
2206+/-138
Closes (90MA)
Opens (90MU)
Closes (90MU)
SUCTION PRESSURE SWITCH
Opens
kPa
kPa
186+/-28
462+/-48
Closes
REFRIGERANT
Typ
R-407C
Qty (90MA ONLY))
kg
1.4
2.4
5.1
4.5
CONDENSER (90MA ONLY)
Number...Type
1…Tube in Tube
3.3
Water Volume
Liter
1.48
9.2
EVAPORATOR AIR FAN
Nominal Flow
Adjustable, Belt Driven Centrifugal: 1750 RPM Motor@60hz
m3/hr
RPM
RPM
cm
1698
2830
4245
5660
Standard Speed Range
Maximum Allowable Speed
Belt Qty/Pulley Pitch Diameter
Motor Pulley Pitch Diameter Range
Motor Nominal Rating (@ 60Hz)…Frame Size
Standard
534-757
534-757
402-570
488-692
1250
1 / 16.3
1 / 16.3
1 / 21.6
1 / 17.8
cm
6.1 to 8.6 cm
kW
kW
kW
0.25…56
0.56…56
N/
0.56…56
0.75…56
N/
0.75…56
1.5…56
2.2…56
1.5…56
2.2…56
N/
Alternate (SeeNote 1)
Alternate (See Note 1)
EVAPORATOR COIL
Tube
3/8 OD, Copper Tubes, Aluminum Fin
Prime
Qty Rows…Fin Spacing
Face Area
Fins/cm
m2
2…5.7
0.46
3…5.7
0.46
3…4.9
0.68
0.79
RETURN AIR FILTERS
Qty…Size
Factory Supplied, Cleanable
2…40.6 x 63.5 x 2.5 4…40.6 x 50.8 x 2.5
cm
CONDENSER CONNECTIONS (90MA ONLY)
Water Inlet (bottom)
Water Outler (top)
Maximum Working Pressure (Refrigerant Side)
CONDENSATE DRAIN CONNECTIONS
ACCESSORY ELECTRIC HEAT
Capacity @ 460 volts
Capacity @ 400 volts
Number of Electric Heat Stages
Inches FPT
Inches FPT
kPa
1/2
1/2
3/4
3/4
1
1
1
1
2758
3/4
Inches FPT
kW
kW
5.25
4.03
1
17.5
13.4
2
LEGEND
FPT = Female Pipe Thread MPT = Male Pipe Thread ODF = Outside Diameter Female
NOTES:
1. Motors other than those furnished with unit must be purchased separately. Contact your Carrier Marine representative
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations
Printed in U.S.A. 90MA-3SI SUPERCEDES FORM 62-02971-00 09-2009
Pg 6
TABLE 2C - 90MA/MU PHYSICAL DATA – R-404A , SI UNITS
BASE UNIT (90MA/MU)
NOMINAL CAPACITY
REFRIGERANT
UNITS
kW
504
10.5
506
17.6
508
26.4
512
35.1
R-
OPERATING WEIGHT
Base unit 90MA
kg
kg
kg
177
150
11.3
194
163
11.3
406
379
22.7
431
404
22.7
Base Unit 90MU
Discharge Plenum
COMPRESSOR TYPE
Qty Cylinders
Qty Unloading Cylinders
Qty Capacity Steps
DISCHARGE PRESSURE SWITCH
Opens (90MA)
Scroll
N/
N/
Semi-Hermetic, Recip
4
0
1
6
2
2
1
kPa
kPa
kPa
kPa
2725+/-69
2034+/-138
2937+/-48
2206+/-138
Closes (90MA)
Opens (90MU)
Closes (90MU)
SUCTION PRESSURE SWITCH
Opens
kPa
kPa
186+/-28
462+/-48
Closes
REFRIGERANT
Typ
R-
Qty (90MA ONLY))
kg
1.4
2.4
5.1
4.5
CONDENSER (90MA ONLY)
Number...Type
1…Tube in Tube
3.3
Water Volume
Liter
1.48
9.2
EVAPORATOR AIR FAN
Nominal Flow
Adjustable, Belt Driven Centrifugal: 1750 RPM Motor@60hz
m3/hr
RPM
RPM
cm
1698
2830
4245
5660
Standard Speed Range
Maximum Allowable Speed
Belt Qty/Pulley Pitch Diameter
Motor Pulley Pitch Diameter Range
Motor Nominal Rating (@ 60Hz)…Frame Size
Standard
534-757
534-757
402-570
488-692
1250
1 / 16.3
1 / 16.3
1 / 21.6
1 / 17.8
cm
6.1 to 8.6 cm
kW
kW
kW
0.25…56
0.56…56
N/
0.56…56
0.75…56
N/
0.75…56
1.5…56
2.2…56
1.5…56
2.2…56
N/
Alternate (SeeNote 1)
Alternate (See Note 1)
EVAPORATOR COIL
Tube
3/8 OD, Copper Tubes, Aluminum Fin
Prime
Qty Rows…Fin Spacing
Face Area
Fins/cm
m2
2…5.7
0.46
3…5.7
0.46
3…4.9
0.68
0.79
RETURN AIR FILTERS
Qty…Size
Factory Supplied, Cleanable
2…40.6 x 63.5 x 2.5 4…40.6 x 50.8 x 2.5
cm
CONDENSER CONNECTIONS (90MA ONLY)
Water Inlet (bottom)
Water Outler (top)
Maximum Working Pressure (Refrigerant Side)
CONDENSATE DRAIN CONNECTIONS
ACCESSORY ELECTRIC HEAT
Capacity @ 460 volts
Capacity @ 400 volts
Number of Electric Heat Stages
Inches FPT
Inches FPT
kPa
1/2
1/2
3/4
3/4
1
1
1
1
2758
3/4
Inches FPT
kW
kW
5.25
4.03
1
17.5
13.4
2
LEGEND
FPT = Female Pipe Thread MPT = Male Pipe Thread ODF = Outside Diameter Female
NOTES:
1. Motors other than those furnished with unit must be purchased separately. Contact your Carrier Marine representative
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations
Printed in U.S.A. 90MA-3SI SUPERCEDES FORM 62-02971-00 09-2009
Pg 7
Step 4 - Rig and Place Unit -
NOTE: Install accessories before placing unit.
a. Provide space around unit for service, filter access, and
overhead clearance as indicated in Figure 2.
b. Move and store unit in upright position.
c. Use slings with spacer under base skid to prevent panel
damage when using hoist.
d. Units as shipped are adequately dampened against
vibration. If additional dampening is desired, place
sponge rubber or rubber mat, between deck and base of
unit or install vibration isolators.
e. Unit should be level. Unit leveling tolerance is 1/8 in. per
linear ft in any direction.
Step 5 - Install Accessory Plenum (If Supplied) - Use
plenum as template to mark hole locations in top panel. Drill
0.154-in. holes in top panel at marked locations and attach
plenum with screws supplied.
FIGURE 1 - BASE UNIT INTERIOR DETAILS
(TYPICAL UNIT SHOWN)
UNIT
A
B
*04
*06
*08,*12
36.13(918)
21.63(549)
59.25(1505)
48.26(1226)
29.88(759)
72.00(1828)
C
D
E
SEE NOTE 2
24(51)
F
G
H
11.25(286)
13.00 (330)
0.75(19)
13.50(343)
15.50(394)
0.75(19)
15.63(397)
18.38(466)
1.00 (25)
J
K
L
M
11.59(294)
10.34(263)
11.37(289)
24.20(615)
25.50(646)
17.11(435)
17.13(435)
20.38(519)
17.11(435)
NOTES:
1. Certified dimension drawings available upon request
2. Minimum required clearance at back of unit is zero.
Clearance above and at right (90MA*08,*12 only) and at
left of unit depends on space required for accessory
plenum, ductwork, condenser piping, accessory heater
piping, condensate drain line and power wiring
3. Water connections are located on left side of unit (Refer
to “Make Condenser Connections”, Condensate drain
connections are located on left side of unit for *04 & *06,
and on both sides of unit for *08 & *12.
FIGURE 2 - UNIT DIMENSIONS
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations
Printed in U.S.A. 90MA-3SI SUPERCEDES FORM 62-02971-00 09-2009
Pg 8
Step 7 - Install Ventilation-Air Ductwork (If required)-
Connect ventilation ducts to flanges on outside-air supply
opening (Figure. 2) using a flexible connection. Attach
ductwork to ship structure, insulate and cover with vapor
barrier to reduce sound transmission and prevent vapor
condensation.
Weatherproof external ductwork, joints, and openings
in accordance with applicable codes. Ducts passing
through an unconditioned space must be insulated and
covered with a vapor barrier.
Step 8 - Check Return-Air Filters - Ensure filters shipped
with unit are in place. Never operate unit without return air
filters in place.
Step 9 - Check Compressor Spring Mounts (*08 & *12
size only) - The compressors are held rigid in shipment by
bolts extending through a washer, grommet and
compressor foot into a weld nut.
Loosen each bolt (4 per compressor) until compressor
floats freely on springs. Then re-tighten bolts until there is
slight pressure on the neoprene gasket. This will steady
the compressor and prevent start and stop rocking.
The compressors have reversible oil pumps that
operate in either direction; therefore, the direction of
rotation need not be checked.
DIMENSION “D” MUST BE
EQUAL ALL AROUND
FIGURE 3 - HORIZONTAL WHEEL CENTERING
Step 10 - Make Condenser Connections
UNIT MOUNTED 90MA UNITS- Piping arrangements for
condenser cooling water are shown in Figure. 5.
Condensers have water inlet and outlet connections as
shown in Figure 6.
Connect condenser water supply and return lines as
indicated. When connecting water lines, hold the
condenser inlet and outlet stubs firmly with a wrench at the
female pipe thread hex fitting to prevent twisting. Do not
use water lines smaller than connection sizes shown in
Figure 6. Observe all applicable plumbing and sanitary
codes.
FIGURE 4 - CONCENTRIC WHEEL ALIGNMENT
Step 6 – Check Fan Shaft and Wheel Alignment-
HORIZONTAL WHEEL CENTERING - All wheels must be
horizontally centered between the inside edges of their fan
scroll ventures (Figure. 3).
Adjust as follows:
a. Loosen set screws holding wheel to shaft.
b. Center the wheel by sliding it horizontally.
c. Re-tighten set screws.
CONCENTRIC ALIGNMENT - Shaft and wheels must be
concentrically centered with the venturi (Figure. 4). Shaft
bearings are supported by bearing supports. If shaft and
wheels are concentrically misaligned from shipping shock,
it is possible to re-bend bearing support arms to original
positions. Replace the bearing support if it has been
extensively damaged during shipping.
FIGURE 5 - TYPICAL CONDENSER WATER PIPING
Install water-regulating valve in water supply line
outside cabinet as follows.
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Pg 9
a. Route regulating valve capillary with its flare nut to the
fitting on refrigerant discharge line (Figure. 1), using
any convenient unused opening on side of unit. Use a
grommet in panel to prevent chafing of capillary.
b. Remove cap from discharge line fitting.
c. Remove cotter pin taped to discharge line fitting. Insert
pin, split end first, into regulating valve flare
d. Hold flare tightly against fitting while connecting flare
nut. Round end of cotter pin will depress core of fitting.
The opened fitting allows refrigerant pressure to act on
water regulating valve. Tighten nut to prevent leakage.
Fitting automatically seals when nut is removed.
90MU UNITS-Install remote mounted condenser in
accordance with the installation instructions provided with
condenser. Recommended line sizes are given in Table 3.
Additional instructions can be found in Carrier System
Design Manual, Part 3, for standard refrigeration piping
techniques. On *08 and *12 size units, secure discharge
line to bracket at unit outlet using proper clamp from
supplied fastener package
Condenserless (90MU) units are shipped with a
refrigerant holding charge. After refrigerant connections
are made, leak test, reclaim refrigerant, evacuate, and
charge system as described in “Service, Charging The
System”.
A = Condensate, ¾ inch Female Pipe Thread,
B = Electrical Opening,
C = Condenser In, 1 inch FPT,
D = Condenser Out, 1 Inch FPT
FIGURE 6 - CONNECTION LOCATIONS
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Pg 10
TABLE 3 - RECOMMENDED LINE SIZES (INCHES) REMOTE CONDENSERS
LENGTH OF RUN
UNIT
REFRIGERANT
90MU
TYPE
0-25
LIQUID
26-50
51-75
76-100
DISCH
1/2
5/8
3/4
7/8
5/8
3/4
7/8
7/8
DISCH
LIQUID
3/8
DISCH
LIQUID
3/8
DISCH
LIQUID
3/8
404
406
408
412
504
506
508
512
R-407C
R-407C
R-407C
R-407C
R-404A
R-404A
R-404A
R-404A
3/8
3/8
1/2
1/2
3/8
1/2
1/2
5/8
5/8
3/4
3/4
7/8
5/8
3/4
7/8
1-1/8
5/8
3/4
7/8
7/8
3/4
7/8
1-1/8
1-1/8
5/8
3/4
7/8
3/8
1/2
1/2
3/8
1/2
1/2
5/8
3/8
1/2
1/2
3/8
1/2
1/2
5/8
3/8
1/2
5/8
3/8
1/2
5/8
5/8
1-1/8
3/4
7/8
1-1/8
1-1/8
* Recommended line sizes correspond to 2 degree F drop.
NOTES:
1. Pipe sizes should never be smaller than cooling unit connection size.
2. Table is based on 2 degree F drop over entire length. Excessive (more than a few) elbows
and fittings will significantly affect pressure drop. If this situation exists, line sizing must be re-
calculated.
Step 11 - Install Unit Drain Line - Install a trapped
condensate drain line at unit drain connection The drain
requires standard pipe connected to condensate pan
nipple(s). Figure 7 shows proper trap design.
Determine design negative static pressure. This
pressure is not the same as fan total static pressure, which
includes pressure losses downstream as well as upstream
from the evaporator air fan. Always assume the worst
conditions, such as having return air filters clogged with
debris.
Referring to Figure 7, differential 1 must be equal to or
larger than negative static pressure at design operating
condition. Store enough water in trap to prevent losing
seal. Differential 2 must be equal to or larger than one-half
the maximum negative static pressure. To avoid loss of
seal when the fan starts, differential 3 must be greater
than the maximum negative static pressure.
Do not use drain line smaller than 3/4 inch. Use hole(s)
provided in panel for drain line. Pitch drain line downward
toward scupper. Installation of a plugged tee is
recommended for cleaning. Fill trap with water to make an
air seal. Observe all sanitary requirements.
FIGURE 7 - CONDENSATE DRAIN TRAP
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Pg 11
Step 12 - Make Electrical Connections
OPERATION
GENERAL - Provide an adequate fused disconnect switch
within sight of the unit. Provision for locking switch open
(OFF) is advisable to prevent power from being turned on
when unit is being serviced.
CAUTION
Compressor crankcase heater must be
energized for 24 hours prior to startup to
prevent compressor bearing damage.
POWER WIRING - Conduit opening for all units is on left
side of unit near control box. Connect field power wires at
the compressor contactor.
To start unit:
Supply voltage must be in accordance with nameplate
voltage. Voltage between phases must be balanced within
2% and current within 10% with compressor running.
Correct improper voltage or phase imbalance. Unit failure
as a result of operation on improper line voltage or
excessive phase imbalance constitutes abuse and shall
void the Carrier warranty. Use the following formula to
determine the percent voltage imbalance.
1. Thoroughly inspect exterior of unit. Clean and dust up
debris, then wash with mild soap and water solution.
2. On 90MA*08 &*12 units, ensure compressor
discharge, suction and liquid service valves are open.
(Refer to “Operation - Service Valves.) Check oil level
in compressor sight glass. If level is below glass, add
oil to bring level to approximately 1/4 glass. If level is
above bottom of glass, do not remove any oil until the
crankcase heater has been energized for at least
twenty-four hours.
3. With selector switch in OFF position, turn main power
on. Leave power on for 24 hours so that crankcase
heater can drive off accumulated refrigerant.
4. If desired, the selector switch may be placed in the
FAN position during the crankcase warm-up period. On
first start-up, check fan speed (Tables 1A/B/C/2A/B/C)
and rotation (Figure 1). If fan requires adjustment, refer
to “Service, Evaporator-Fan Adjustment”.
5. Allow crankcase heater to remain energized (unit
power on) for at least 24 hours. Open any valves in
condenser cooling water supply lines and then set
selector switch at COOL position. If room temperature
is above thermostat setting compressor will start. On
first start-up, set water regulating valve. (Refer to
“Service, Water Regulating Valve.)
6. Set thermostat for comfort as desired.
To Shut Down Unit:
1. Turn selector switch to OFF position. Do not shut off
main power except to service unit. The crankcase
heater is operative only when main power is on. (Refer
to “Service, Crankcase Heater”).
2. If unit is to be used for winter heating, set selector
switch at HEAT position and re-set thermostat at
desired setting.
3. If unit may be exposed to freezing temperatures, drain
water from condenser and water piping. Add a non-
corrosive antifreeze to residual water in system.
CONTROL WIRING - On extended voltage (208/230-v)
units, the control transformer is factory wired for 208-v
usage. If unit is to be used on 230-v system, reconnect
primary wiring on transformer. See Figure 12
(90MA*04/*06) or figure 14 (90MA*08/*12).
On all units, the thermostat is factory installed. A
sensing element is provided in the return air. To wire these
units to a remote thermostat, or to a remote control switch
and thermostat, refer to unit Wiring Diagram or contact
your Carrier Transicold representative.
Service Valves - Always ensure that compressor suction,
and discharge service valves and liquid service valve are
open before operating unit.
The valves are accessible from the front of the unit. To
open valve, turn counterclockwise. After opening, replace
and tighten valve cap to prevent leakage.
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Pg 12
SERVICE
WARNING
NEVER reach into unit while
fan is running. LOCK OPEN
AND TAG unit disconnect
before working on fan. Remove
fuses and take them with you
after noting this on tag.
CAUTION
1. Sharp edges of coil fins are exposed. To
prevent injury, cover top of evaporator
with cardboard or a few layers of heavy
tape.
2. To avoid coil damage, cover evaporator
face with plywood or other rigid sheet
material. If any coil fins are mashed or
bent, straighten with a coil fin comb of the
proper tooth spacing (refer to “coil
fins/inch” in Table 1). Check for
refrigerant leaks.
FIGURE 8 - FAN PULLEY ADJUSTMENT
6. Check pulley alignment and belt tension adjustment as
described below.
7. Check fan operation. Repeat above procedure as
required.
Return-Air Grille Removal
1. Pull grille out from top.
2. Pull grille up to release hinge pins from lower panel.
3. To reassemble, reverse procedure.
PULLEY ALIGNMENT - Shut off unit power supply.
Loosen fan motor pulley set screws and slide fan pulley
along fan shaft. Make angular alignment by loosening
motor from mounting bracket (See Figure. 8).
Access Panel Removal - Remove return-air grille as
described above.
BELT TENSION ADJUSTMENT - Shut off unit power
supply. Loosen fan motor from mounting bracket. Do not
loosen motor mounting bracket from unit. Move fan motor
up or down until proper belt tension is achieved (approxi-
mately 3/4-in. deflection with 8-pound tension at midpoint
of belt span).
Remove the panel fastening screws now exposed.
TOP PANEL - Pull out and down.
BOTTOM - Pull out and up.
Evaporator Fan Adjustment - Observe fan compartment
Caution note above. The fan motor pulleys are factory set
at the fan speeds listed in Table 1.
Lubrication - Fan motor and fan shaft bearings are
lubricated for the life of the bearings. No re-lubrication is
required
TO CHANGE FAN SPEED
1. Shut off unit power supply.
Return-Air Filters - Inspect filters twice monthly and clean
as required by operating conditions. Filter size and type
are listed in Tables 1A/B/C/2A/B/C. To clean filters flush
with hot water or steam or soak in a mild water solution of
soap or detergent. Refer to filter manufacturer's
instructions as applicable.
2. Loosen fan belt by loosening fan motor from mounting
bracket. Do not loosen fan motor mounting bracket
from unit.
3. Loosen movable pulley flange set screw (Figure. 8).
4. Screw movable flange toward fixed flange to increase
fan speed and away from fixed flange to decrease
speed. Increasing fan speed increases load on motor.
Do not exceed maximum allowable fan speed (Tables
1A/B/C/2A/B/C) or motor full load amps indicated on
motor nameplate.
Do not operate unit without return-air filters in place.
Condensate Drains - Clean the drain line and unit drain
pan at the start of each cooling season. Check flow by
pouring water into drain. Be sure trap is filled as shown in
Figure. 7 to maintain an air seal.
5. Set movable flange set screw at nearest flat of pulley
hub and tighten set screw.
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Pg 13
Evaporator Coil - Observe fan compartment Caution note
at the beginning of the Service section.
Remove dirt and debris from evaporator coil as
required by condition. Clean coil with a stiff brush, vacuum
cleaner or compressed air. Use a fin comb of the correct
tooth spacing (Refer to Tables 1A/B/C/2A/B/C for coil
fins/inch) when straightening mashed or bent coil fins.
Water Regulating Valve
PREPARATION FOR OPERATION.
1. Open the water regulating valve inlet and outlet
isolation valves.
2. Close the water regulating valve bypass valve.
ADJUSTMENT
NOTE: Adjustments to the water regulating
valve must be made slowly, allowing ample
time for response and stabilization.
FIGURE 9 - GRAVITY FLOW METHOD
1. The compressor discharge pressure is controlled by
the water regulating valve and may be monitored by
observing liquid line pressure.
2. Install a calibrated gauge at the liquid line service port.
FOR 90MA: Operating liquid line range for R-407C
units is 200 to 215 psig, operating range for R-404A
units is 240 to 260 psig, operating range for R-134a
units is 122 to 130 psig.
GRAVITY FLOW METHOD (Figure. 9) -
1. Disconnect condenser piping at unit, including isolation
valves and water regulating valve.
2. Fill condenser as shown in figure 9. Follow acid
manufacturer's instructions. When condenser is full,
allow solution to remain overnight
3. Drain condenser and flush with clean water.
FOR 90MU : Operating liquid line range for R-407C
units is 265 to 285 psig, operating range for R-404A
units is 290 to 315 psig, If pressure reading is below
operating range, rotate the square head adjusting
screw counterclockwise; this will increase spring
tension, decrease water flow and increase pressure.
If pressure reading is above operating range, rotate the
square head adjusting screw clockwise; this will
decrease spring tension, increase water flow and
decrease pressure.
FORCED CIRCULATION METHOD (Figure. 10) -
1. Disconnect condenser piping at unit, including isolation
valves and water regulating valve.
2. Fill system as shown in figure 10. Follow acid
manufacturer's instructions. Fully open vent pipe when
filling system. The vent may be closed when system is
full and pump is operating.
3. Regulate flow to condenser with a supply line valve. If
pump is a non-overloading type, the valve may be fully
closed while pump is running. For average scale
deposit, allow solution to remain in condenser
overnight. For heavy scale deposit, allow 24 hours.
4. Drain condenser and flush with clean water.
3. Only the water regulating valve opening point is
adjustable. The closing point is 3 to 7 psig below the
opening point and is non-adjustable.
Condenser - Condensers may require cleaning of water-
deposited scale.
CAUTION
Follow all Safety codes. Wear safety glasses
and rubber gloves when using inhibited
hydrochloric acid solution.
Clean condensers with an inhibited hydrochloric acid
solution. The acid can stain hands and clothing, attack
concrete and, without inhibitor, can attack steel. Cover
surroundings to guard against splashing. Vapors from vent
pipe are not harmful, but take care to prevent liquid from
being carried over by the gases.
Warm solution acts faster, but cold solution is just as
effective if applied for a longer period.
FIGURE 10 - FORCED CIRCULATION METHOD
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Pg 14
Charging the System (90MA) - These units are shipped
with a full operating charge. If recharging is necessary
(complete charge lost), weigh in amount of refrigerant
indicated on unit nameplate and in Table 1.
If unit has partial charge, it must be recharged by
removing existing charge and recharging by weighing in
the required amount of refrigerant. (Refer to Table
1A/B/C/2A/B/C)
Evaporator-Fan Motor Removal - Motor power wires
need not be disconnected from motor terminals before
motor is removed from unit.
1. Shut off unit main power supply.
WARNING
LOCK OPEN AND TAG unit disconnect
before working on fan motor. Remove fuses
and take them with you after noting this on
tag.
Charging the System (90MU)
UNIT SIZES 90MU Units - These units, used with remote
condensers, are shipped with a holding charge only. To
charge:
CAUTION
Before attempting to remove fan motors or
motor mounts, place a piece of plywood over
evaporator coils to prevent coil damage.
1. Open discharge and liquid service valves.
2. Leak test, reclaim refrigerant and evacuate.
3. Using standard refrigerant charging techniques and
subcooling charts (Figure 11) add refrigerant as required
to maintain proper operating conditions. Subcooling is
determined by subtracting the actual temperature entering
the TXV from the saturated temperature entering the TXV.
2. Loosen motor hold down bolts on mounting bracket so
that fan belt can be removed.
3
Loosen but do not remove the 2 motor mounting
bracket bolts on left side of bracket.
4
Slide motor/bracket assembly to extreme right, remove
bolts and lift out through space between fan scroll and
side Rest motor on a high platform such as a step
ladder. Do not allow motor to hang by its power wires.
IMPORTANT: Charge on both the HIGH and LOW side
simultaneously of idle compressors to prevent axial
loading of the scroll, which may cause a temporary no
start condition for the compressor. If this occurs, leave
the system off for approximately 30 minutes. Attempt
to restart the compressor; internal pressures should
equalize enough to allow compressor to start.
If removing the compressor, evacuate both the HIGH
and LOW side simultaneously.
Pressure Relief Device - All units are equipped with a
fusible-plug type safety relief device an the refrigerant
tubing. The relief setting is 197 °F to 203 °F on all units.
Crankcase Heater - A Crankcase heater is supplied on
90MA,MU*08 and *12 size units. The heater prevents
liquid refrigerant from accumulating in the compressor
crankcase during extended shutdown periods. Heater is
automatically energized whenever unit main power is on
and compressor is stopped. Heater is de-energized when
compressor starts.
Do not shut off main power supply for an extended
period except for servicing unit. Turn on power supply for
at least 24 hours after an extended shutdown before
starting compressor. Refer to “Operation”.
R407C PRESSURE AT LIQUID LINE SERVICE VALVE PSIG
137 149 162 176 205 222 239 256 275 295 315 336 359
Required
Subcooling (ºF)
0
5
10
15
20
25
70
65
60
55
50
45
75
70
65
60
55
50
80
75
70
65
60
55
85
80
75
70
65
60
90
85
80
75
70
65
95 100 105 110 115 120 125 130
90
85
80
75
70
95 100 105 110 115 120 125
90
85
80
75
95 100 105 110 115 120
90
85
80
95 100 105 110 115
90
85
95 100 105 110
90 95 100 105
Required
Subcooling (ºF)
R404A PRESSURE AT LIQUID LINE SERVICE VALVE PSIG
150 163 176 190 205 221 237 255 273 292 313 334 356
0
5
10
15
20
25
70
65
60
55
50
45
75
70
65
60
55
50
80
75
70
65
60
55
85
80
75
70
65
60
90
85
80
75
70
65
95 100 105 110 115 120 125 130
90
85
80
75
70
95 100 105 110 115 120 125
90
85
80
75
95 100 105 110 115 120
90
85
80
95 100 105 110 115
90
85
95 100 105 110
90 95 100 105
Cycle-LocTM- Protection Device - All units are equipped
with Cycle-LOC current-sensing lockout relay. This device
will lock out the compressor after any safety trip (discharge
pressure switch, suction-pressure switch, or internal
overload of the compressor). Check reason for lockout
before resetting the device. Refer to unit label wiring
diagram. To reset, turn the system switch to OFF, then
back to COOL.
Required
Subcooling (ºC)
R407C PRESSURE AT LIQUID LINE SERVICE VALVE kPa
1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300
0
3
5
7
10
13
23
20
18
16
13
10
26
23
21
19
16
13
29
26
24
22
19
16
32
29
27
25
22
19
34
31
29
27
24
21
37
34
32
30
27
24
39
36
34
32
29
26
42
39
37
35
32
29
44
41
39
37
34
31
46
43
41
39
36
33
48
45
43
41
38
35
50
47
45
43
40
37
52
49
47
45
42
39
Required
Subcooling (ºC)
R404A PRESSURE AT LIQUID LINE SERVICE VALVE kPa
1190 1288 1392 1503 1580 1701 1786 1918 2011 2107 2206 2308 2414
0
3
5
7
10
13
23
20
18
16
13
10
26
23
21
19
16
13
29
26
24
22
19
16
32
29
27
25
22
19
34
31
29
27
24
21
37
34
32
30
27
24
39
36
34
32
29
26
42
39
37
35
32
29
44
41
39
37
34
31
46
43
41
39
36
33
48
45
43
41
38
35
50
47
45
43
40
37
52
49
47
45
42
39
Discharge and Suction Pressure Switches - Refer to
Table 1 for opening and closing settings for these safety
devices.
The discharge pressure switch is located on the
compressor on 06DA compressor equipped units and on
the discharge line on all other units. The suction pressure
switch is located on top of the compressor on 06DA
FIGURE 11 - CHARGING CHARTS
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Pg 15
compressor equipped units and on the suction line on all
other units.
Oil Charge - All units are factory charged with oil. On 06D
compressors, observe the oil level in the sight glass at
start-up. If unit oil level is below sight glass, add oil until
level reaches approximately 1/4 sight glass.
If oil charge is above sight glass, do not remove any oil
until the compressor crankcase heater has been energized
for at least 24 hours.
When additional oil or a complete charge is required,
use only the following Carrier approved oil.
R-407C, R-404A, and R-134a units
Castrol - Icematic SW68
ICI - Emkarate RL68HP
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90MA-3SI SUPERCEDES FORM 62-02971-00 09-2009
Pg 16
FOR NOTES AND LEGEND, SEE FIGURE 13
FIGURE 12 WIRING SCHEMATIC - 90MA/MU*04/*06
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Pg 17
FIGURE 13 COMPONENT ARRANGEMENT - 90MA/MU*04/*06
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Pg 18
FOR NOTES AND LEGEND, SEE FIGURE 15
FIGURE 14 - ELECTRICAL SCHEMATIC - 90MA/MU*08/*12
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90MA-3SI SUPERCEDES FORM 62-02971-00 09-2009
Pg 19
FIGURE 15 - COMPONENT ARRANGEMENT - 90MA/MU008/012
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Pg 20
FIGURE 16 – MOUNTING BASE ASSEMBLY – 90MA/MU*04/*06
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Pg 21
FIGURE 17 – MOUNTING BASE ASSEMBLY – 90MA/MU*08/*12
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90MA-3SI SUPERCEDES FORM 62-02971-00 09-2009
Pg 22
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