38AH044-134
Air-Cooled Condensing Units
50/60 Hz
Installation, Start-Up and
Service Instructions
CONTENTS
INSTALLATION
Page
Step 1 — Rig and Place Unit — All units are
designed for overhead rigging, and it is important that this
method be used. Lifting holes are provided in the frame base
rails, which are marked for rigging (see rigging label on the
unit and Tables 1, 2A, and 2B for rigging weights and center
of gravity). It is recommended that field-supplied pipes, of
sufficient length to extend at least 12-in. (305 mm) beyond
the frame, be passed through the holes.
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . .
1
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-37
Step 1 — Rig and Place Unit . . . . . . . . . . . . . . .
• DOMESTIC UNITS
1
• EXPORT UNITS
• PLACING UNITS
Step 2 — Check Compressor Mounting . . . . .
• UNITS 38AH044-084
3
• UNITS 38AH094-134
Step 3 — Make Refrigerant Piping
To maintain unit stability while lifting, use 4 cables,
chains, or straps of equal length. Attach one end of
each cable to one pipe end and the other end of each
cable to the overhead rigging point.
Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
• UNITS 38AH044-084
• UNITS 38AH094-134
Step 4 — Make Electrical Connections . . . . . . 23
• POWER SUPPLY
Use spreader bars or frame to keep the cables, chains,
and straps clear of the unit sides. Leave standard coil pro-
tection packaging in place during rigging to provide protec-
tion to coils. Remove and discard all coil protection after
rigging cables are detached.
• FIELD POWER CONNECTIONS
• MAIN POWER
• CONTROL CIRCUIT WIRING
Step 5 — Install Accessories . . . . . . . . . . . . . . . 37
• LOW-AMBIENT OPERATION
• MISCELLANEOUS ACCESSORIES
DOMESTIC UNITS — For units 38AH044-084, 124, and
134; standard unit packaging consists of coil protection only.
There is no standard packaging provided for units 38AH094
and 104. Skids are not provided. If overhead rigging is not
available at the jobsite, place the unit on a skid or pad before
dragging or rolling. When rolling, use a minimum of
3 rollers. When dragging, pull the pad or skid. Do not apply
force to the unit. When in final position, raise from above to
lift unit off the pad or skid.
PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . 37,38
START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38-45
SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46-49
CONTROL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49-52
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . 53,54
START-UP CHECKLIST . . . . . . . . . . . . . . . CL-1, CL-2
EXPORT UNITS — All export units are mounted on skids
with vertical coil protection. Leave the unit on the skid until
it is in final position. While on the skid, the unit can be rolled
or skidded. Apply force to the skid, not to the unit. Use a
minimum of 3 rollers when rolling. When in final position,
raise from above to remove the skid.
SAFETY CONSIDERATIONS
Installing, starting up, and servicing this equipment can
be hazardous due to system pressures, electrical compo-
nents, and equipment location (roofs, elevated structures, etc.).
Only trained, qualified installers and service mechanics
should install, start up, and service this equipment.
PLACING UNITS
Units 38AH044-084 — Refer to Fig. 1 and 2 for airflow clear-
ances. Recommended minimum clearances are 6 ft (1829 mm)
for unrestricted airflow and service on sides of unit, 5 ft
(1524 mm) on ends, and unrestricted clear air space above
the unit. Provide ample space to connect liquid and suction
lines to indoor unit. For multiple units, allow 8 ft (2440 mm)
separation between units for airflow and service.
Untrained personnel can perform basic maintenance func-
tions, such as cleaning coils. All other operations should be
performed by trained service personnel.
When working on the equipment, observe precautions in
the literature, and on tags, stickers, and labels attached to the
equipment and any other safety precautions that may apply.
• Follow all safety codes.
• Wear safety glasses and work gloves.
• Use care in handling, rigging, and setting bulky
equipment.
Do not forklift these units unless the unit is attached to
a skid designed for forklifting.
ELECTRIC SHOCK HAZARD.
Open all remote disconnects before servicing
this equipment.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1
PC 111
Catalog No. 563-704
Printed in U.S.A.
Form 38AH-15SI
Pg 1
10-98
Replaces: 38AH-14SI
Tab 3a
Remove sheet metal cover panels from return-bend end of
Module 124B or 134B. Place Module 124B or 134B in
position. The exposed return-bend ends of each module are
now opposite each other and facing the service space. The
compressors of each module are on opposite sides of the unit.
Step 2 — Check Compressor Mounting
UNITS 38AH044-084 — Compressors are mounted on pans
and are held down by 4 bolts during shipment. After unit is
installed, loosen each of these bolts until the snubber washer
can be moved with finger pressure. See Fig. 10.
IMPORTANT: Modules must be placed 24 in.
(610 mm) apart and square relative to each other.
UNITS 38AH094-134 — Units 38AH094 and 104 compres-
sors are mounted on rails and held down by rail bolts during
shipment. After unit is installed, loosen the rail bolts to al-
low the rails and compressors to float freely on the springs
located under the rails. See Fig. 10.
Units 38AH124 and 134 compressors are mounted on pans
and are held down by 4 bolts during shipment. After unit is
installed, loosen each of these bolts until snubber washer can
be moved with finger pressure. See Fig. 10.
The modules are now in position for piping installa-
tion and final assembly. See Fig. 8. For mounting units on
vibration isolators, a perimeter support channel is required
between the assembled unit and the support isolators. The
perimeter support channel must be sized to support the fully
assembled unit. Do not support modules on individual iso-
lation supports. Support channel, hardware, and fasteners are
field supplied.
When unit is in proper location, level unit and bolt into
position with field-supplied bolts.
Table 2A — Operational Corner Weights with
Refrigerant Charge (Approximate) — Lb
Table 2B — Operational Corner Weights with
Refrigerant Charge (Approximate) — Kg
OPERATIONAL CORNER WEIGHT
OPERATIONAL CORNER WEIGHT
UNIT
38AH
TOTAL
WEIGHT
UNIT
38AH
TOTAL
WEIGHT
A
B
C
D
A
B
C
D
044
3259
3547
3309
3597
3565
3998
3812
4229
4057
4735
5088
5813
5435
6160
939
893
695
765
697
771
765
874
777
862
827
965
1182
1350
1302
1476
732
802
742
814
771
879
903
1035
961
1159
601
686
755
856
044
1478
1609
1501
1632
1617
1813
1729
1918
1840
2148
2308
2637
2465
2794
426
460
437
469
462
510
520
577
553
646
505
577
562
637
405
438
411
444
459
508
447
481
476
538
994
1136
970
1099
316
347
316
350
347
397
352
391
375
438
536
612
591
670
332
364
337
369
350
399
410
470
436
526
272
311
342
388
044C
054
1013
964
967
044C
054
905
054C
064
1034
1018
1125
1146
1272
1220
1425
1114
1273
1240
1405
978
054C
064
1011
1117
986
064C
074
064C
074
074C
084
1059
1049
1186
2192
2504
2138
2423
074C
084
084C
094
084C
094
094C
104
094C
104
104C
104C
MODULE
38AH
MODULE
38AH
124A
3630
4063
3630
4063
3630
4063
3877
4294
1037
1144
1037
1144
1037
1144
1167
1293
1030
1137
1030
1137
1030
1137
997
779
889
779
889
779
889
789
874
785
894
785
894
785
894
924
1047
124A
1647
1843
1647
1843
1647
1843
1759
1948
470
519
470
519
470
519
529
587
467
516
467
516
467
516
452
490
353
403
353
403
353
403
358
396
356
405
356
405
356
405
419
475
124A-C
124B
124A-C
124B
124B-C
134A
124B-C
134A
134A-C
134B
134A-C
134B
134B-C
1080
134B-C
LEGEND
C — Copper Fin Coils
LEGEND
C — Copper Fin Coils
NOTE: Total weight may differ from summation of corner weights due
to rounding of numerals.
NOTE: Total weight may differ from summation of corner weights due
to rounding of numerals.
TOP VIEW, TYPICAL
3
DUAL CKT
SINGLE CKT
SUCTION
CONNECTION(S)
21⁄8Љ Dia [54 mm]
25⁄8Љ Dia [67 mm]
LIQUID
CONNECTION(S)
7
⁄
8Љ Dia [22 mm]
11⁄8Љ Dia [29 mm]
SUCTION C
LIQUID D
2Ј-11⁄16Љ [627mm] 1Ј-105⁄16Љ [567mm]
1Ј-101⁄16Љ [561mm] 1Ј-105⁄16Љ [567mm]
SUCTION (Ckt A) 1Ј-713⁄16Љ [503mm] 2Ј-5⁄8
SUCTION (Ckt B) 2Ј-5⁄8
[626mm]
Љ
[626mm]
Љ
—
LIQUID (Ckt A)
LIQUID (Ckt B)
2Ј-53⁄4
2Ј-105⁄8
Љ
[756mm] 2Ј-105⁄8
Љ
[879mm]
Љ
[879mm]
—
Chart 1, Field Power Supply Connections
UNIT
044
VOLTAGE
230
Hz DIAMETER — in. [mm] QTY
50
60
35⁄8 [92]
35⁄8 [92]
21⁄2 [63]
21⁄2 [63]
21⁄2 [63]
35⁄8 [92]
1
1
1
1
2
1
208/230
044, 054
346, 380/415 50
044, 054, 064 460,575,380 60
208/230 60
346, 380/415 50
064
LEGEND
C
MTG
SAE
—
—
—
Copper Fin Coils
Mounting
Society of Automotive Engineers
NOTES:
1. The approximate operating weight of the unit is:
38AH-044---
38AH-044--C
38AH-054---
38AH-054--C
38AH-064---
38AH-064--C
3259 lb [1478 kg]
3547 lb [1609 kg]
3309 lb [1501 kg]
3597 lb [1632 kg]
3565 lb [1617 kg]
3998 lb [1813 kg]
2. Unit must have clearances for airflow as follows:
Top — Do not restrict in any way.
Ends — 5 ft [1524 mm]
Sides — 6 ft [1829 mm]
3. Mounting holes may be used to mount unit to concrete pad. They are not recommended for mounting
unit to spring isolators. If spring isolators are used, a perimeter support channel between the unit and
the isolators is recommended.
4. One 35⁄8Љ (92 mm) diameter hole is recommended for single-entry power on size 064 (208/230-v) units.
5. See Table 1 for rigging center of gravity (Dimensions X,Y). See Table 2A and 2B for A-D corner weights.
6. Circled numerals in Top View refer to condenser fans by position.
Fig. 1 — Dimensions — Units 38AH044,054,064
4
DUAL CKT
SINGLE CKT
SUCTION
CONNECTION(S)
21⁄8Љ Dia [54 mm]
25⁄8Љ Dia [67 mm]
LIQUID
CONNECTION(S)
7
⁄
8Љ Dia [22 mm]
11⁄8Љ Dia [29 mm]
SUCTION C
LIQUID D
2Ј-11⁄16Љ [627mm] 1Ј-105⁄16Љ [567mm]
1Ј-101⁄16Љ [561mm] 1Ј-105⁄16Љ [567mm]
SUCTION (Ckt A) 1Ј-713⁄16Љ [503mm] 2Ј-5⁄8
SUCTION (Ckt B) 2Ј-5⁄8
[626mm]
Љ
[626mm]
Љ
—
LIQUID (Ckt A)
LIQUID (Ckt B)
2Ј-53⁄4
2Ј-105⁄8
Љ
[756mm] 2Ј-105⁄8
Љ
[879mm]
Љ
[879mm]
—
Chart 1, Field Power Supply Connections
UNIT
074
VOLTAGE
208/230
460
Hz DIAMETER — in. [mm] QTY
60
60
50
60
60
60
60
21⁄2 [63]
21⁄2 [63]
35⁄8 [92]
35⁄8 [92]
21⁄2 [63]
35⁄8 [92]
35⁄8 [92]
2
1
1
1
1
2
1
346, 380/415
380
074, 084
084
575
208/230
460
LEGEND
C
MTG
SAE
—
—
—
Copper Fin Coils
Mounting
Society of Automotive Engineers
NOTES:
1. The approximate operating weight of the unit is:
38AH-074---
38AH-074--C
38AH-084---
38AH-084--C
3812 lb (1729 kg)
4229 lb (1918 kg)
4057 lb (1840 kg)
4735 lb (2148 kg)
2. Unit must have clearances for airflow as follows:
Top — Do not restrict in any way.
Ends — 5 ft [1524 mm]
Sides — 6 ft [1829 mm]
3. Mounting holes may be used to mount unit to concrete pad. They are not recommended for mounting unit
to spring isolators. If spring isolators are used, a perimeter support channel between the unit and the iso-
lators is recommended.
4. See Table 1 for rigging center of gravity (Dimensions X,Y). See Table 2A and 2B for A-D corner weights.
5. Circled numerals in Top View refer to condenser fans by position.
Fig. 2 — Dimensions — Units 38AH074,084
5
Chart 1, Field Power Supply Connections
LEGEND
UNIT
38AH
VOLTAGE
Hz DIAMETER — in. (mm) QUANTITY
C
—
—
—
Copper Fin Coils
MTG
SAE
Mounting
208/230
60
60
35⁄8 (92)
35⁄8 (92)
35⁄8 (92)
2
1
1
Society of Automotive Engineers
460, 575,
380
094
NOTES:
1. The approximate operating weight of the unit is:
346, 380/415 50
38AH-094---
38AH-094--C
5088 lb (2308 kg)
5813 lb (2637 kg)
2. Unit must have clearances for airflow as follows:
Top — Do not restrict in any way.
Ends — 5 ft [1524 mm]
Sides — 6 ft [1829 mm]
3. Mounting holes may be used to mount unit to concrete pad. They are not
recommended for mounting unit to spring isolators.
4. Two 35⁄8Љ (92-mm) dia holes are recommended for parallel conductors on
208/230 v units.
5. Circled numerals in Top View refer to condenser fans by position.
6. If spring isolators are used, a perimeter support channel between the unit
and the isolators is recommended.
7. See Table 1 for rigging center of gravity (Dimensions X,Y). See Table 2A
and 2B for A-D corner weights.
Fig. 3 — Dimensions — Unit 38AH094
6
LEGEND
Chart 1, Field Power Supply Connections
C
MTG
SAE
—
—
—
Copper Fin Coils
Mounting
UNIT
38AH
VOLTAGE
Hz DIAMETER — in. (mm) QUANTITY
Society of Automotive Engineers
208/230
60
60
35⁄8 (92)
35⁄8 (92)
35⁄8 (92)
2
1
1
NOTES:
1. The approximate operating weight of the unit is:
460, 575,
380
104
38AH-104---
38AH-104--C
5435 lb (2465 kg)
6160 lb (2794 kg)
346, 380/415 50
2. Unit must have clearances for airflow as follows:
Top — Do not restrict in any way.
Ends — 5 ft [1524 mm]
Sides — 6 ft [1829 mm]
3. Mounting holes may be used to mount unit to concrete pad. They are not
recommended for mounting unit to spring isolators.
4. Two 35⁄8Љ (92-mm) dia holes are recommended for parallel conductors on
208/230 v units.
5. Circled numerals in Top View refer to condenser fans by position.
6. If spring isolators are used, a perimeter support channel between the unit
and the isolators is recommended.
7. See Table 1 for rigging center of gravity (Dimensions X,Y). See Table 2A
and 2B for A-D corner weights.
Fig. 4 — Dimensions — Unit 38AH104
7
Chart 1, Field Power Supply Connections
NOTES:
1. The approximate operating weight of the unit is:
UNIT
DIAMETER
(in.)
35⁄8 (92)
21⁄2 (63)
35⁄8 (92)
38AH-124---
38AH-124--C
7260 lb (3293 kg)
8126 lb (3686 kg)
VOLTAGE
Hz
60
60
QUANTITY
38AH
2. Unit must have clearances for airflow as follows:
Top — Do not restrict in any way.
208/230
1
1
1
124A
124B
460, 575,
380
Ends — 5 ft [1524 mm]
Sides — 6 ft [1829 mm]
3. Mounting holes may be used to mount unit to concrete pad. They are not rec-
ommended for mounting unit to spring isolators.
346, 380/415 50
4. One 35⁄8Љ (92-mm) dia hole is recommended for single-entry power into each
module (124A and 124B) of the 208/230-v units.
LEGEND
5. Circled numerals in Top View refer to condenser fans by position.
6. If spring isolators are used, a perimeter support channel between the unit and
the isolators is recommended. Do not support each module separately.
7. Each module of the unit must be rigged into position separately. The unit must
not be rigged after modules have been connected.
C
MTG
SAE
—
—
—
Copper Fin Coils
Mounting
Society of Automotive Engineers
8. Suction and liquid connections can exit on either side of the unit.
9. Field power supply connections are required for each module.
10. See Table 1 for rigging center of gravity (Dimensions K,L,X,Y). See Table 2A
and 2B for A-D corner weights.
Fig. 5 — Dimensions — Unit 38AH124
8
NOTES:
Chart 1, Field Power Supply Connections
DIAMETER —
1. The approximate operating weight of the unit is:
38AH-134---
38AH-134--C
7507 lb (3405 kg)
8357 lb (3791 kg)
UNIT
38AH
VOLTAGE
Hz
QUANTITY
in. (mm)
35⁄8 (92)
21⁄2 (63)
35⁄8 (92)
21⁄2 (63)
21⁄2 (63)
35⁄8 (92)
35⁄8 (92)
2. Unit must have clearances for airflow as follows:
Top — Do not restrict in any way.
208/230
460, 575, 380
346, 380/415
208/230
60
60
50
60
60
60
50
1
1
1
2
1
1
1
Ends — 5 ft [1524 mm]
Sides — 6 ft [1829 mm]
134A
3. Mounting holes may be used to mount unit to concrete pad. They are not
recommended for mounting unit to spring isolators.
4. One 35⁄8Љ (92-mm) dia hole is recommended for single-entry power into
Module 134A and 208/230-v units. Single entry power into Module 134B is
not recommended.
460, 575
134B
380
5. Circled numerals in Top View refer to condenser fans by position.
6. If spring isolators are used, a perimeter support channel between the as-
sembled unit and the isolators is recommended. Do not support each mod-
ule separately.
346, 380/415
7. Each module of the unit must be rigged into position separately. The unit
must not be rigged after modules have been connected.
8. Suction and liquid connections can exit on either side of the unit.
9. Field power supply connections are required for each module.
10. See Table 1A or 1B for rigging center of gravity (Dimensions K,L,X,Y). See
Table 2A and 2B for A-D corner weights.
LEGEND
C
MTG
SAE
—
—
—
Copper Fin Coils
Mounting
Society of Automotive Engineers
Fig. 6 — Dimensions — Unit 38AH134
9
Table 3A — Units 38AH044-084 Physical Data — 50/60 Hz (English)
38AH
044
054
064
074
084
OPERATING WEIGHT WITH
REFRIGERANT (Approx) — Lb
Cu-Al
Cu-Cu
3259
3547
3309
3597
3565
3998
3812
4229
4057
4735
SHIP WEIGHT WITH COIL PROTECTION ONLY
(Approx) — Lb
Cu-Al
Cu-Cu
3250
3538
3290
3578
3530
3963
3780
4197
4000
4678
TYPICAL OPERATING REFRIGERANT
Charge (Approx) — Lb
Qty of Circuits
R-22
88
2
62
2
1
72
2
1
104
2
1
130
2
1
Std
Opt
1
COMPRESSOR Type...Rpm
(Qty Cylinder) Compressor*
Model No. 06E
Reciprocating Semi-Hermetic...1750 @ 60 Hz; 1458 @ 50 Hz
Std
Std
Opt
Opt
Std
Opt
(4) A1
(4) B1
250
(4) A1
250
(6) A1
265
17
(6) B1
265
(6) A1
265
(6) A1
275
21
(6) B1
275
(6) A1
275
(6) B1
299
(6) A1
(6) B1
299
250
(4) A1
250
17
299
(6) A1
299
19
(Qty Cylinder) Compressor*
Model No. 06E
(4) A2
250
(4) A2
250
(6) A2
265
(6) A1
299
(6) A2
275
(6) A2
299
Oil Charge (Pt)
17
17
21
21
21
19
19
19
17
21
17
21
21
19
21
19
Capacity Control Steps†
4
CONDENSER FANS (6 Blade) — 60 Hz
Qty...Dia (in.)
4...30
6...30
Airflow (Cfm)
35,000
1140
6.2
52,000
51,000
Speed (Rpm)
Total Power (kW)
1140
9.3
CONDENSER FANS (6 Blade) — 50 Hz
Qty...Dia (in.)
4...30
35,000
950
6...30
Airflow (Cfm)
52,000
51,000
Speed (Rpm)
Total Power (kW)
950
9.3
6.2
CONDENSER COIL
Enhanced Copper Tubes, Aluminum Lanced Fin
Rows...Fins per in.
2...17
80.5
35
2...17
80.5
35
3...17
80.5
55
2...19
116.7
55
3...17
116.7
80
Face Area (sq ft)
Storage Capacity (Lb per Circuit) at 120 F
CONNECTIONS
Suction, ODF (in.)**
Liquid, ODF (in.)**
Hot Gas Bypass, ODF (in.)
21⁄8
7
⁄
⁄
8
8
5
Table 3B — Units 38AH044-084 Physical Data — 50/60 Hz (SI)
38AH
044
054
064
074
084
OPERATING WEIGHT WITH
REFRIGERANT (Approx) — Kg
Cu-Al
Cu-Cu
1478
1609
1501
1632
1617
1813
1729
1918
1840
2148
SHIP WEIGHT WITH COIL PROTECTION ONLY
(Approx) — Kg
Cu-Al
Cu-Cu
1474
1605
1492
1623
1601
1798
1715
1904
1814
2122
TYPICAL OPERATING REFRIGERANT
CHARGE (Approx) — Kg
Qty of Circuits
R-22
39.9
2
28.1
2
1
32.7
2
1
47.2
2
1
58.9
2
1
Std
Opt
1
COMPRESSOR Type...R/s
(Qty Cylinder) Compressor*
Model No. 06E
Reciprocating Semi-Hermetic...29.2 @ 60 Hz; 24.3 @ 50 Hz
Std
Std
Opt
Opt
Std
Opt
(4) A1
(4) B1
250
(4) A1
250
(6) B1
265
(6) A1
265
(6) B1
275
(6) A1
275
(6) B1
299
(6) A1
(6) B1
299
250
(4) A1
250
299
(6) A1
299
(Qty) Cylinder) Compressor*
Model No. 06E
(4) A2
250
(6) A1
265
(4) A2
250
(6) A1
275
(6) A2
265
(6) A1
299
(6) A2
275
(6) A2
299
Oil Charge (L)
8.0
8.0
8.0
8.0
8.0
9.9
9.9
9.9
9.9
9.0
9.0
9.0
9.0
9.0
9.9
8.0
9.9
9.9
9.0
9.9
Capacity Control Steps†
4
CONDENSER FANS (6 Blade) — 50 Hz
Qty...Dia (mm)
4...762
6...762
Airflow (L/s)
16,500
15.8
6.2
24,500
24,100
Speed (R/s)
Total Power (kW)
15.8
9.3
CONDENSER FANS (6 Blade) — 60 Hz
Qty...Dia (mm)
4...762
16,500
19.0
6...762
Airflow (L/s)
24,500
24,100
Speed (R/s)
Total Power (kW)
19.0
9.3
6.2
CONDENSER COIL
Enhanced Copper Tubes, Aluminum Lanced Fin
Rows...Fins per m
2...669
7.48
16
2...669
7.48
16
3...669
7.48
25
2...782
10.84
25
3...669
10.84
36
Face Area (sq m)
Storage Capacity (Kg per Circuit) at 48.9 C
CONNECTIONS
Suction, ODF (in.)**
Liquid, ODF (in.)**
Hot Gas Bypass, ODF (in.)
21⁄8
7
⁄
⁄
8
8
5
LEGEND
**For single-circuit units, suction ODF is 25⁄8 in. (66.7 mm) and liquid ODF is
11⁄8 in. (28.6 mm). Single circuits have a factory-installed manifold; no
field modification is required.
Cu-Al
Cu-Cu
ODF
Opt
—
—
—
—
—
Copper tubes with aluminum fins
Copper tubes with copper fins
Outside Diameter, Female
Optional Single-Circuit Units
Standard Dual-Circuit Units
NOTES:
1. Certified dimensional drawings available on request.
2. Equivalent connection values in mm are as follows:
Std
in.
mm
*Compressor A1 is lead on standard and optional single-circuit units.
†Capacity control steps listed are for constant-volume units with no accesso-
ries. Refer to Table 19A or 19B, page 48, for additional system capacity
information.
5
⁄
8
8
15.9
22.2
54.0
7
⁄
21⁄8
10
Table 4A — Units 38AH094-134 Physical Data — 50/60 Hz (English)
124
134
38AH
094
104
124A
124B
134A
134B
OPERATING WEIGHT WITH
Cu-Al
5088
5813
5435
6160
3630*
4063*
3630*
4063*
3630*
4063*
3877*
4294*
REFRIGERANT (Approx) — Lb Cu-Cu
SHIP WEIGHT WITH
Cu-Al
5630
6355
5990
6715
3907*
4340*
3907*
4340*
3907*
4340*
4080*
4497*
COIL PROTECTION AND SKID Cu-Cu
(Approx) — Lb
TYPICAL OPERATING
REFRIGERANT CHARGE
(Approx) — Lb
R-22
148
2
135
2
88
1
88
1
88
1
104
1
Qty of Circuits
COMPRESSOR Type...Rpm
(Qty Cylinder) Compressor†
Model No. 06E
Reciprocating Semi-Hermetic...1750 @ 60 Hz; 1460 @ 50 Hz
(6)A1 (4)A2 (6)B1 (6)A1 (4)A2 (6)B1 (6)B2 (6)A1 (6)A2 (6)A1 (6)A2 (6)A1 (6)A2 (6)A1 (6)A2
−275 −250 −299 −265 −250 −265 −265 −275 −265 −275 −265 −275 −265 −299 −275
Oil Charge (Pt)
21
17
5
19
21
17
21
21
21
21
21
21
21
21
19
21
Capacity Control Steps**
6
3
3
3
3
CONDENSER FANS (6 Blade) — 60 Hz
Qty...Dia (in.)
6...30
52,000
1140
9.4
6...30
4...30
4...30
4...30
6...30
Airflow (Cfm)
52,000
1140
9.5
35,000
1140
6.4
35,000
1140
6.4
35,000
1140
6.4
52,000
1140
9.2
Speed (Rpm)
Total Power (kW)
CONDENSER FANS (6 Blade) — 50 Hz
Qty...Dia (in.)
6...30
52,000
950
6...30
52,000
950
4...30
35,000
950
4...30
35,000
950
4...30
35,000
950
6...30
52,000
950
Airflow (Cfm)
Speed (Rpm)
Total Power (kW)
9.4
9.5
6.4
6.4
6.4
9.2
CONDENSER COIL
Rows...Fins per in.
Face Area (sq ft)
Enhanced Copper Tubes, Aluminum Lanced Fin
3...17
128.3
3...17
128.3
3...17
80.5
3...17
80.5
3...17
80.5
2...19
116.7
Storage Capacity
178
178
110
110
110
110
(Lb per circuit) at 120 F
CONNECTIONS
Suction, ODF (in.)
Liquid, ODF (in.)
21⁄8
7
21⁄8
7
25⁄8
25⁄8
25⁄8
25⁄8
⁄
8
8
⁄
8
8
11⁄8
5
11⁄8
5
11⁄8
5
11⁄8
5
5
5
Hot Gas Bypass, ODF (in.)
⁄
⁄
⁄8
⁄8
⁄
8
⁄
8
Table 4B — Units 38AH094-134 Physical Data — 50/60 Hz (SI)
124
134
38AH
094
104
124A
124B
134A
134B
OPERATING WEIGHT WITH
Cu-Al
2308
2637
2465
2794
1647*
1843*
1647*
1843*
1647*
1843*
1759*
1948*
REFRIGERANT (Approx) — Kg Cu-Cu
SHIP WEIGHT WITH
Cu-Al
2554
2883
2717
3046
1860*
1968*
1860*
1968*
1860*
1968*
1851*
1968*
COIL PROTECTION AND SKID Cu-Cu
(Approx) — Kg
TYPICAL OPERATING
REFRIGERANT CHARGE
(Approx) — Kg
R-22
67.1
2
61.2
2
39.9
1
39.9
1
39.9
1
47.2
1
Qty of Circuits
COMPRESSOR Type...R/s
(Qty Cyliner) Compressor†
Model No. 06E
Reciprocating Semi-Hermetic...29.2 @ 60 Hz; 24.3 @ 50 Hz
(6)A1 (4)A2 (6)B1 (6)A1 (4)A2 (6)B1 (6)B2 (6)A1 (6)A2 (6)A1 (6)A2 (6)A1 (6)A2 (6)A1 (6)A2
−275 −250 −299 −265 −250 −265 −265 −275 −265 −275 −265 −275 −265 −299 −275
Oil Charge (L)
10
8
5
9
10
8
10
10
10
10
10
10
10
10
9
10
Capacity Control Steps**
6
3
3
3
3
CONDENSER FANS (6 Blade) — 60 Hz
Qty...Dia (mm)
6...762
24,544
19
6...762
24,544
19
4...762
16,520
19
4...762
16,520
19
4...762
16,520
19
6...762
24,544
19
Airflow (L/s)
Speed (R/s)
Total Power (kW)
9.4
9.5
6.4
6.4
6.4
9.2
CONDENSER FANS (6 Blade) — 50 Hz
Qty...Dia (mm)
6...762
24,544
15.8
6...762
24,544
15.8
4...762
16,520
15.8
4...762
16,520
15.8
4...762
16,520
15.8
6...762
24,544
15.8
Airflow (L/s)
Speed (R/s)
Total Power (kW)
9.4
9.5
6.4
6.4
6.4
9.2
CONDENSER COIL
Rows...Fins per m
Face Area (sq m)
Storage Capacity
(Kg per circuit) at 49 C
Enhanced Copper Tubes, Aluminum Lanced Fin
3...669.3
11.9
3...669.3
11.9
3...669.3
7.5
3...669.3
7.5
3...669.3
7.5
2...781.6
10.8
81
81
50
50
50
50
CONNECTIONS
Suction, ODF (in.)
Liquid, ODF (in.)
21⁄8
7
21⁄8
7
25⁄8
25⁄8
25⁄8
25⁄8
⁄
8
8
⁄
8
8
11⁄8
5
11⁄8
5
11⁄8
5
11⁄8
5
5
5
Hot Gas Bypass, ODF (in.)
⁄
⁄
⁄8
⁄8
⁄
8
⁄
8
LEGEND
NOTES:
1. Unit 38AH124 consists of one 124A module and one 124B module. Unit
38AH134 consists of one 134A module and one 134B module.
2. Certified dimensional drawings available on request.
Cu-Al
Cu-Cu
ODF
—
—
—
Copper Tubes with Aluminum Fins
Copper Tubes with Copper Fins
Outside Diameter, Female
3. Equivalent connection values in mm are as follows:
*Includes piping and trim kit.
†Compressors are shipped with minimum oil charge.
**Capacity control steps listed are for constant volume units with no accesso-
ries. Refer to Table 20, page 48, for additional system capacity information.
in.
mm
5
⁄
8
8
15.9
22.2
28.6
54.0
66.7
7
⁄
11⁄8
21⁄8
25⁄8
11
Fig. 7 — Modules 38AH124A or 134A — Shipping Locations of Piping
and Sheet Metal Trim Kit
CONTROL
BOX
SHEET METAL COVER
PANEL (REMOVED)
RIG
HERE
RIG
HERE
RIG
HERE
24-in. (610-mm)
SERVICE SPACE
RIG
HERE
Fig. 8 — Correct Placement of Modules Without Piping
and Sheet Metal Trim (Unit 38AH134 Shown)
12
Fig. 9B — Field-Installed Suction Line Loop
FACTORY-
INSTALLED
SUCTION
LINE LOOP
Fig. 9A — Typical Module with Cover
Panels Removed
38AH044-084,124,134
MOUNTING SPRINGS
SHIPMENT BOLTS
SHIPMENT BOLTS
38AH094,104
MOUNTING
BOLTS
MOUNTING
BOLTS
RAIL BOLT (3) (2 SHOWN)
RAIL BOLT (3) (2 SHOWN)
Fig. 10 — Outer View, Compressor Mounting
13
38AH044-084 optional single-circuit units) shows required
location of solenoid valves and recommended locations for
the filter driers and sight glasses. Complete the refrigerant
piping from the evaporator to the condenser before opening
the liquid and suction lines at the condenser.
Step 3 — Make Refrigerant Piping
Connections
The field-supplied liquid line solenoid valve must be
installed at the evaporator to avoid possible compressor
damage during unit operation. See Fig. 11 (for 38AH044-
084 dual-circuit and 38AH094-134 units), or Fig. 12 (for
38AH044-084 optional single-circuit units).
Table 5 — Liquid Lift
MAXIMUM LIQUID LIFT
UNIT
60 Hz
50 Hz
38AH
Ft
69
75
75
45
75
55
50
75
45
M
Ft
M
044
054
064
074
084
094
104
124
134
21.0
23.0
23.0
13.7
23.0
16.7
15.2
23.0
13.7
57.5
75.0
65.0
37.5
75.0
46.0
42.0
65.0
37.5
17.5
23.0
19.8
11.4
23.0
14.0
12.8
19.8
11.4
The units have large suction lines to minimize friction losses.
The units also have the ability to operate at low capacity.
Because of these capabilities, use special care with suction
piping and suction risers to ensure proper compressor oil
return under all operating conditions. Maximum allowable
vertical separation between the condensing unit and the evapo-
rator is shown in Table 5. Size suction lines in accordance
with Tables 6A or 6B through 9A or 9B and Fig. 13. Mount
liquid line solenoid valve just ahead of the TXVs (thermo-
static expansion valves) which will be mounted at the
evaporator. See Fig. 11 (for 38AH044-084 dual-circuit and
38AH094-134 units) or Fig. 12 (for 38AH044-084 optional
single-circuit units).
To achieve good mixing of the refrigerant leaving the evapo-
rator suction header for proper sensing by the TXV bulb:
1. Install a minimum of two 90-degree elbows upstream of
the TXV bulb location. See Fig. 14 (for 38AH044-084
dual-circuit and 38AH094-134 units) or Fig. 15 (for
38AH044-084 optional single-circuit units).
UNITS 38AH044-084 — Relieve the pressure caused by the
holding charge into a refrigerant recovery system. Uncap
the suction line and cut the run-around tube at the liquid line
as close to the loop elbow as possible. This will leave
approximately 2 in. (50 mm) of straight tube for liquid line
connection.
IMPORTANT: Protect the liquid valves from the heat
of brazing.
2. Locate the TXV bulb on a vertical riser, where possible.
If a horizontal location is necessary, secure the bulb at
approximately the 4 o’clock position.
Leak test the entire system by using soap bubbles and
nitrogen or R-22 with an electronic leak detector.
3. Size the suction line from the evaporator to the common
suction line to achieve high refrigerant velocity. See
Tables 6A or 6B through 9A or 9B and Fig. 13.
Purge nitrogen or reclaim R-22 from system after com-
pletion of leak-checking procedure. Repair leak if one is
found. When finished, evacuate and dehydrate system using
the methods described in Carrier GTAC II (General Training
Air Conditioning II), Module 4, System Dehydration.
If an oil return connection at the bottom of the suction
header is supplied with an evaporator, tee-in this connection
ahead of first mixing elbow. See Fig. 14 (for 38AH044-084
dual-circuit and 38AH094-134 units) or Fig. 15 (for 38AH044-
084 optional single-circuit units). When the compressor is
below the evaporator, the riser at the evaporator should ex-
tend to the top of the evaporator section. After the riser is
installed, the suction line can elbow down immediately.
Install a field-supplied filter drier and sight glasses in each
refrigerant system. Select the filter drier for maximum unit
capacity and minimum pressure drop. Figure 11 (for 38AH044-
084 dual-circuit and 38AH094-134 units) or Fig. 12 (for
UNITS 38AH094-134 — Relieve the R-22 holding charge
of each circuit into a refrigerant recovery system. Remove
the liquid line to factory-installed suction line loop by cut-
ting the loop at the liquid valve. (See Fig. 9A and 9B.) Cut
as close to the 90-degree bend in the loop as possible. The
remaining tube piece in the valve will be used for brazing
the liquid line. Unbraze and remove the cap from the liquid
line. For 38AH094 and 104 units, sweat-connect the liquid
and suction lines from the evaporator. For 38AH124 and 134
units, see Piping Kit Connections on page 21.
LEGEND
LLS
TXV
—
—
Liquid Line Solenoid
Thermostatic Expansion Valve
*Field-Supplied.
Fig. 11 — Required Location of Solenoid Valves and Recommended Filter Drier and
Sight Glass Locations for 38AH044-084 Dual-Circuit and 38AH094-134 Units
14
*Field-Supplied.
Fig. 12 — Required Location of Solenoid Valves and Recommended Filter Drier and
Sight Glass Locations for 38AH044-084 Optional Single-Circuit Units
LEGEND
PIPE D DIAMETER
A
—
—
—
—
—
—
Pipe A, Suction Riser, without Trap
Pipe B, Suction Riser with Trap
Suction Line to Condensing Unit
Pipe D, Suction Riser Short Lift
Reducer
Dual Circuit*
UNIT
38AH
B
Single Circuit*
A
B
C
D
RED.
STR
in.
mm
in.
mm
in.
mm
044
15⁄8
15⁄8
15⁄8
21⁄8
21⁄8
21⁄8
25⁄8
41
41
41
54
54
54
67
15⁄8
15⁄8
21⁄8
21⁄8
21⁄8
21⁄8
25⁄8
41
41
54
54
54
54
67
21⁄8
21⁄8
21⁄8
21⁄8
54
54
54
54
67†
—
Street
054
NOTES:
064
1. Short riser, pipe D, is used when routing suction line to condens-
ing unit connection. See table at right.
074
084
25⁄8
—
†
2. See Tables 6A-9B for values of A, B, and C.
094, 104
124, 134
—
—
*Maximum length of riser is 3 ft (914 mm).
†Double suction riser required if accessory unloader is field
installed.
Fig. 13 — Double Suction Riser Construction
15
Table 6A — Refrigerant Piping Requirements — 38AH044-104 Dual-Circuit Units — 60 Hz
TOTAL LINEAR LENGTH OF INTERCONNECTING PIPE — FT (M)
UNIT
38AH
15-25
(4.6-7.6)
25-50
(7.6-15.2)
50-75
(15.2-22.9)
75-100
(22.9-30.5)
100-150
(30.5-45.7)
150-200
(45.7-61.0)
L
S
S
S
S
S
S
5
Ckt A
⁄
⁄
8
8
15⁄8
15⁄8
21⁄8
21⁄8
21⁄8
21⁄8
044
054
064
074
084
094
104
5
Ckt B
15⁄8
15⁄8
21⁄8
21⁄8
21⁄8
21⁄8
5
7
7
7
7
7
7
7
Ckt A
Ckt B
⁄
⁄
8
8
15⁄8
15⁄8
⁄
8
8
15⁄8
21⁄8
⁄
⁄
8
8
21⁄8
21⁄8
⁄
8
21⁄8
21⁄8
⁄
8
21⁄8
21⁄8
⁄
8
21⁄8
25⁄8
7
⁄
11⁄8
11⁄8
11⁄8
7
7
7
7
7
7
Ckt A
Ckt B
⁄
⁄
8
8
15⁄8
⁄
8
8
21⁄8
⁄
⁄
8
8
21⁄8
⁄
8
21⁄8
11⁄8
21⁄8
11⁄8
7
21⁄8
⁄
21⁄8
21⁄8
11⁄8
21⁄8
11⁄8
25⁄8
11⁄8
7
7
7
Ckt A
Ckt B
⁄
⁄
8
8
21⁄8
21⁄8
⁄
8
21⁄8
21⁄8
⁄
8
21⁄8
21⁄8
11⁄8
21⁄8
25⁄8
11⁄8
13⁄8
25⁄8
†
†
†
†
11⁄8
13⁄8
7
11⁄8
11⁄8
11⁄8
25⁄8
7
Ckt A
Ckt B
⁄
⁄
8
8
21⁄8
11⁄8
21⁄8
11⁄8
21⁄8
11⁄8
11⁄8
25⁄8
†
13⁄8
25⁄8
25⁄8
13⁄8
7
21⁄8
11⁄8
21⁄8
11⁄8
21⁄8
25⁄8
13⁄8
13⁄8
7
Ckt A
Ckt B
⁄
⁄
8
8
21⁄8
21⁄8
11⁄8
21⁄8
21⁄8
11⁄8
11⁄8
25⁄8
†
11⁄8
25⁄8
†
13⁄8
11⁄8
25⁄8
13⁄8
13⁄8
7
7
⁄
8
21⁄8
11⁄8
25⁄8
25⁄8
7
Ckt A
Ckt B
⁄
⁄
8
8
21⁄8
11⁄8
21⁄8
11⁄8
25⁄8
25⁄8
†
11⁄8
11⁄8
25⁄8
†
13⁄8
25⁄8
13⁄8
7
21⁄8
11⁄8
21⁄8
11⁄8
25⁄8
13⁄8
31⁄8**
13⁄8
LEGEND
5. Suction and liquid line sizing is based on pressure drop equivalent
to 2 F (1.1 C) at nominal rating conditions. Higher pressure drop
design criteria may allow selection of smaller pipe sizes, but at a
penalty of decreased system capacity and efficiency.
6. Double suction risers may be required if condensing unit is
elevated above the evaporator. See footnotes and double suction
riser table below.
7. Refer to Carrier System Design Manual or to E20-II design
programs for further information on selecting pipe sizes for split
systems.
8. All pipe sizes are OD inches. Equivalent sizes in millimeters
follow:
L
S
—
—
Liquid Line
Suction Line
*Double suction riser required on units with field installed unloader
on circuit B compressor if condensing unit is elevated above
evaporator.
†Double suction riser required on units with field installed unloader
on circuit B compressor if condensing unit is elevated above
evaporator.
**Double suction riser required on all unit configurations if condens-
ing unit is elevated above evaporator.
NOTES:
in.
mm
1. Addition of
2
unloaders to circuit
B
compressor is not
5
⁄
⁄
8
15.9
22.2
28.6
34.9
41.3
54.0
66.7
79.4
recommended.
7
8
2. 38AH094 and 38AH104 piping sizes apply only to factory sup-
plied unit configurations. They do NOT take into account any field
installed unloaders.
11⁄8
13⁄8
15⁄8
21⁄8
25⁄8
31⁄8
3. Piping sizes are based on unit operation above 40 F (4.4 C) satu-
rated suction temperature (SST). When operating below 40 F
(4.4 C), refer to Carrier System Design Manual, E20-IIா piping de-
sign program, or ASHRAE Handbook to select proper line sizes.
4. Pipe sizes are based on the total linear length shown for each
column, plus a 50% allowance for fittings.
Table 6B — Refrigerant Piping Requirements for Double Suction Risers,
38AH054-104 Dual-Circuit Units — 60 Hz
TOTAL LINEAR LENGTH OF INTERCONNECTING PIPE — FT (M)
UNIT
38AH
50-75
(15.2-22.9)
75-100
(22.9-30.5)
100-150
(30.5-45.7)
150-200
(45.7-61.0)
A
B
C
A
B
C
A
B
C
A
B
C
Ckt A
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
054
064
074
084
094
104
Ckt B
15⁄8
21⁄8
25⁄8
Ckt A
Ckt B
—
—
—
—
—
—
—
—
—
—
—
—
—
—
15⁄8
—
15⁄8
—
15⁄8
—
—
—
21⁄8
—
21⁄8
—
21⁄8
—
—
—
25⁄8
—
25⁄8
—
25⁄8
—
15⁄8
—
15⁄8
—
15⁄8
—
15⁄8
—
21⁄8
—
21⁄8
—
21⁄8
—
25⁄8
—
25⁄8
—
25⁄8
—
25⁄8
—
31⁄8
—
Ckt A
Ckt B
—
—
—
—
—
—
—
—
15⁄8
—
15⁄8
—
13⁄8
—
—
—
21⁄8
—
21⁄8
—
21⁄8
—
—
—
25⁄8
—
25⁄8
—
25⁄8
—
Ckt A
Ckt B
—
—
15⁄8
—
13⁄8
—
—
—
21⁄8
—
21⁄8
—
—
—
25⁄8
—
25⁄8
—
Ckt A
Ckt B
Ckt A
Ckt B
13⁄8
13⁄8
21⁄8
25⁄8
25⁄8
31⁄8
15⁄8
25⁄8
31⁄8
15⁄8
25⁄8
31⁄8
LEGEND
3. Suction and liquid line sizing is based on pressure drop equivalent
to 2 F (1.1 C) at nominal rating conditions. Higher design pressure
drop criteria may allow selection of smaller pipe sizes but at a pen-
alty of decreased system capacity and efficiency.
4. Refer to Carrier System Design Manual or to E20-II design
programs for further information on selecting pipe sizes for split
systems.
—
—
—
—
—
Not Required
Pipe A
Pipe B
Pipe C
Suction Riser Without Trap
Suction Riser With Trap
Suction Line to Condensing Unit
NOTES:
1. See Refrigerant Piping Requirements table at top of page to
determine need for double suction risers.
2. Pipe sizes are based on the total linear length, shown for each
column, plus a 50% allowance for fittings.
5. All pipe sizes are OD inches. See Table 6A notes for metric
equivalents.
6. Refer to Fig. 13 for double suction riser construction.
16
Table 7A — Refrigerant Piping Requirements, 38AH044-104 Dual-Circuit Units — 50 Hz
TOTAL LINEAR LENGTH OF INTERCONNECTING PIPE — FT (M)
UNIT
38AH
15-25
(4.6-7.6)
25-50
(7.6-15.2)
50-75
(15.2-22.9)
75-100
(22.9-30.5)
100-150
(30.5-45.7)
150-200
(45.7-61.0)
L
S
S
S
S
S
S
5
Ckt A
⁄
⁄
8
8
13⁄8
15⁄8
15⁄8
21⁄8
21⁄8
21⁄8
044
054
064
074
084
094
104
5
Ckt B
13⁄8
15⁄8
15⁄8
21⁄8
21⁄8
21⁄8
5
7
7
7
7
7
7
7
Ckt A
Ckt B
⁄
⁄
8
8
13⁄8
15⁄8
⁄
⁄
8
8
15⁄8
15⁄8
⁄
⁄
8
8
15⁄8
21⁄8
⁄
⁄
8
8
21⁄8
21⁄8
⁄
8
21⁄8
⁄
8
21⁄8
7
7
11⁄8
21⁄8
11⁄8
25⁄8*†
7
7
7
7
7
7
Ckt A
Ckt B
⁄
⁄
8
8
15⁄8
⁄
⁄
8
8
15⁄8
⁄
⁄
8
8
21⁄8
†
⁄
⁄
8
8
21⁄8
†
11⁄8
21⁄8
†
*
11⁄8
25⁄8**
7
7
15⁄8
21⁄8
21⁄8
21⁄8
11⁄8
25⁄8
11⁄8
25⁄8
25⁄8
*
7
7
7
7
7
Ckt A
Ckt B
⁄
⁄
8
8
15⁄8
21⁄8
⁄
⁄
8
8
21⁄8
21⁄8
⁄
8
21⁄8
21⁄8
⁄
8
21⁄8
25⁄8
11⁄8
11⁄8
25⁄8
†
11⁄8
11⁄8
†
7
11⁄8
11⁄8
25⁄8
25⁄8
7
7
7
Ckt A
Ckt B
⁄
⁄
8
8
21⁄8
⁄
⁄
8
8
21⁄8
11⁄8
21⁄8
11⁄8
25⁄8
†
11⁄8
25⁄8
25⁄8
†
11⁄8
25⁄8
†
7
21⁄8
21⁄8
11⁄8
21⁄8
11⁄8
25⁄8
11⁄8
11⁄8
25⁄8
7
Ckt A
Ckt B
⁄
⁄
8
8
21⁄8
21⁄8
11⁄8
21⁄8
21⁄8
11⁄8
11⁄8
25⁄8**
21⁄8
11⁄8
11⁄8
25⁄8**
25⁄8*†
11⁄8
11⁄8
25⁄8**
13⁄8
11⁄8
31⁄8**
25⁄8*†
7
7
⁄
8
25⁄8*†
7
7
Ckt A
Ckt B
⁄
⁄
8
8
21⁄8
⁄
8
21⁄8
11⁄8
21⁄8
11⁄8
25⁄8**
11⁄8
25⁄8**
25⁄8
13⁄8
31⁄8**
7
21⁄8
11⁄8
21⁄8
11⁄8
25⁄8
11⁄8
25⁄8
13⁄8
13⁄8
31⁄8**
LEGEND
5. Suction and liquid line sizing is based on pressure drop equivalent
to 2 F (1.1 C) at nominal rating conditions. Higher pressure drop
design criteria may allow selection of smaller pipe sizes, but at a
penalty of decreased system capacity and efficiency.
6. Double suction risers may be required if condensing unit is
elevated above the evaporator. See footnotes and double suction
riser table below.
7. Refer to Carrier System Design Manual or to E20-II design
programs for further information on selecting pipe sizes for split
systems.
8. All pipe sizes are OD inches. Equivalent sizes in millimeters
follow:
L
S
—
—
Liquid Line
Suction Line
*Double suction riser required on units with field installed unloader
on circuit B compressor if condensing unit is elevated above
evaporator.
†Double suction riser required on units with field installed unloader
on circuit B compressor if condensing unit is elevated above
evaporator.
**Double suction riser required on all unit configurations if condens-
ing unit is elevated above evaporator.
NOTES:
in.
mm
1. Addition of
2
unloaders to circuit
B
compressor is not
5
⁄
⁄
8
15.9
22.2
28.6
34.9
41.3
54.0
66.7
79.4
recommended.
7
8
2. 38AH094 and 38AH104 piping sizes apply only to factory sup-
plied unit configurations. They do NOT take into account any field
installed unloaders.
11⁄8
13⁄8
15⁄8
21⁄8
25⁄8
31⁄8
3. Piping sizes are based on unit operation above 40 F (4.4 C) satu-
rated suction temperature (SST). When operating below 40 F
(4.4 C), refer to Carrier System Design Manual, E20-IIா piping de-
sign program, or ASHRAE Handbook to select proper line sizes.
4. Pipe sizes are based on the total linear length shown for each
column, plus a 50% allowance for fittings.
Table 7B— Refrigerant Piping Requirements for Double Suction Risers,
38AH054-104 Dual-Circuit Units — 50 Hz
TOTAL LINEAR LENGTH OF INTERCONNECTING PIPE — FT (M)
UNIT
38AH
50-75
(15.2-22.9)
75-100
(22.9-30.5)
100-150
(30.5-45.7)
150-200
(45.7-61.0)
A
B
C
A
B
C
A
B
C
A
B
C
Ckt A
—
—
13⁄8
—
—
—
15⁄8
—
—
—
21⁄8
—
—
—
13⁄8
—
—
—
15⁄8
—
—
—
21⁄8
—
—
—
—
—
—
—
—
—
—
054
064
074
084
094
104
Ckt B
15⁄8
21⁄8
25⁄8
Ckt A
Ckt B
15⁄8
15⁄8
21⁄8
15⁄8
21⁄8
25⁄8
15⁄8
21⁄8
25⁄8
15⁄8
21⁄8
25⁄8
Ckt A
Ckt B
—
—
—
—
—
—
—
—
15⁄8
—
13⁄8
13⁄8
13⁄8
—
—
—
21⁄8
—
21⁄8
21⁄8
21⁄8
—
—
—
25⁄8
—
25⁄8
25⁄8
25⁄8
—
15⁄8
—
15⁄8
—
15⁄8
15⁄8
15⁄8
—
21⁄8
—
21⁄8
—
21⁄8
21⁄8
21⁄8
—
25⁄8
—
25⁄8
—
25⁄8
25⁄8
25⁄8
—
15⁄8
—
15⁄8
—
15⁄8
15⁄8
21⁄8
—
21⁄8
—
25⁄8
21⁄8
25⁄8
—
25⁄8
—
31⁄8
25⁄8
Ckt A
Ckt B
—
—
13⁄8
—
—
—
21⁄8
—
—
—
25⁄8
—
Ckt A
Ckt B
Ckt A
Ckt B
—
—
—
—
—
—
15⁄8
25⁄8
31⁄8
15⁄8
25⁄8
31⁄8
LEGEND
3. Suction and liquid line sizing is based on pressure drop equivalent
to 2 F (1.1 C) at nominal rating conditions. Higher design pressure
drop criteria may allow selection of smaller pipe sizes but at a pen-
alty of decreased system capacity and efficiency.
4. Refer to Carrier System Design Manual or to E20-II design
programs for further information on selecting pipe sizes for split
systems.
—
—
—
—
—
Not Required
Pipe A
Pipe B
Pipe C
Suction Riser Without Trap
Suction Riser With Trap
Suction Line to Condensing Unit
NOTES:
1. See Refrigerant Piping Requirements table at top of page to
determine need for double suction risers.
2. Pipe sizes are based on the total linear length, shown for each
column, plus a 50% allowance for fittings.
5. All pipe sizes are OD inches. See Table 7A notes for metric
equivalents.
6. Refer to Fig. 13 for double suction riser construction.
17
Table 8A — Refrigerant Piping Requirements for 38AH044-084
Optional Single-Circuit Units and 38AH124,134
Modular Units (Dual-Circuit) — 60 Hz
TOTAL LINEAR LENGTH OF INTERCONNECTING PIPE — FT (M)
UNIT
38AH
15-20
(4.6-6.1)
20-50
(6.1-15.2)
50-75
(15.2-22.9)
75-100
(22.9-30.5)
100-150
(30.5-45.7)
150-200
(45.7-61.0)
L
S
21⁄8
21⁄8
S
21⁄8
25⁄8
L
11⁄8
11⁄8
S
21⁄8
25⁄8
L
11⁄8
11⁄8
S
25⁄8
25⁄8
L
13⁄8
13⁄8
S
25⁄8
31⁄8
L
13⁄8
13⁄8
S
31⁄8
31⁄8
7
044
054
⁄
⁄
8
*
*
*
*
*
7
8
064;
Modules 124A,
124B,134A
11⁄8
21⁄8
11⁄8
25⁄8
†
11⁄8
25⁄8
†
13⁄8
31⁄8
*
13⁄8
31⁄8
*
13⁄8
31⁄8
*
074;
11⁄8
11⁄8
21⁄8
25⁄8
11⁄8
11⁄8
25⁄8
25⁄8
†
13⁄8
13⁄8
31⁄8
31⁄8
†
13⁄8
13⁄8
31⁄8
31⁄8
†
13⁄8
15⁄8
31⁄8
35⁄8
†
15⁄8
15⁄8
35⁄8
35⁄8
*
Module 134B
084
†
†
†
†
†
*
LEGEND
design criteria may allow selection of smaller pipe sizes, but at a
penalty of decreased system capacity and efficiency.
5. Double suction risers may be required if condensing unit is
elevated above the evaporator. See footnotes and double suction
riser table below.
6. Refer to Carrier System Design Manual, E20-II design program,
or ASHRAE Handbook for further information on selecting pipe
sizes for split systems.
7. All pipe sizes are OD inches. Equivalent sizes in millimeters
follow:
CV
L
—
—
—
—
Constant Volume
Liquid Line
S
Suction Line
VAV
Variable Air Volume
*Double suction riser required on all units configurations if condens-
ing unit is elevated above evaporator.
†Double suction riser required on units with factory installed VAV op-
tion or CV units with additional field installed unloader on circuit A1
(lead) compressor if condensing unit is elevated above evaporator.
in.
mm
NOTES:
7
1. Addition of field-installed unloaders on A2 (lag) compressor is not
recommended.
⁄
8
22.2
28.6
34.9
41.3
54.0
66.7
79.4
92.1
11⁄8
13⁄8
15⁄8
21⁄8
25⁄8
31⁄8
35⁄8
2. Piping sizes are based on unit operation above 40 F (4.4 C) satu-
rated suction temperature (SST). When operating below 40 F
(4.4 C), refer to Carrier System Design Manual, E20-IIா piping
design program, or ASHRAE Handbook to select proper line sizes.
3. Pipe sizes are based on the total linear length shown for each
column, plus a 50% allowance for fittings.
4. Suction and liquid line sizing is based on pressure drop equivalent
to 2 F (1.1 C) at nominal rating conditions. Higher pressure drop
Table 8B — Refrigerant Piping Requirements for Double Suction Risers,
38AH044-084 Optional Single-Circuit Units and 38AH124,134
Modular Units (Dual-Circuit) — 60 Hz
TOTAL LINEAR LENGTH OF INTERCONNECTING PIPE — FT
UNIT
38AH
15-50
(4.6-15.2)
50-75
(15.2-22.9)
75-100
(22.9-30.5)
100-150
(30.5-45.7)
150-200
(45.7-61.0)
A
B
C
A
B
C
A
15⁄8
—
B
21⁄8
—
C
25⁄8
—
A
15⁄8
15⁄8
B
21⁄8
25⁄8
C
25⁄8
31⁄8
A
15⁄8
15⁄8
B
25⁄8
25⁄8
C
31⁄8
31⁄8
044
054
—
—
—
—
—
—
—
—
—
—
—
—
064
Modules 124A,
124B,134A
15⁄8
21⁄8
25⁄8
15⁄8
21⁄8
25⁄8
15⁄8
25⁄8
31⁄8
15⁄8
25⁄8
31⁄8
15⁄8
25⁄8
31⁄8
074;
15⁄8
15⁄8
21⁄8
21⁄8
25⁄8
25⁄8
15⁄8
15⁄8
25⁄8
25⁄8
31⁄8
31⁄8
15⁄8
15⁄8
25⁄8
25⁄8
31⁄8
31⁄8
15⁄8
21⁄8
25⁄8
31⁄8
31⁄8
35⁄8
21⁄8
21⁄8
31⁄8
31⁄8
35⁄8
35⁄8
Module 134B
084
LEGEND
3. Suction and liquid line sizing is based on pressure drop equivalent
to 2 F (1.1 C) at nominal rating conditions. Higher design pressure
drop criteria may allow selection of smaller pipe sizes but at a pen-
alty of decreased system capacity and efficiency.
4. Refer to Carrier System Design Manual or to E20-II design
programs for further information on selecting pipe sizes for split
systems.
—
—
—
—
—
Not Required
Pipe A
Pipe B
Pipe C
Suction Riser Without Trap
Suction Riser With Trap
Suction Line to Condensing Unit
NOTES:
1. See Refrigerant Piping Requirements table at top of page to de-
termine need for double suction risers.
2. Pipe sizes are based on the total linear length, shown for each
column, plus a 50% allowance for fittings.
5. All pipe sizes are OD inches. See Table 8A notes for metric
equivalents.
6. Refer to Fig. 13 for double suction riser construction.
18
Table 9A — Refrigerant Piping Requirements for 38AH044-084
Optional Single-Circuit Units and 38AH124,134
Modular Units (Dual Circuit) — 50 Hz
TOTAL LINEAR LENGTH OF INTERCONNECTING PIPE — FT (M)
UNIT
38AH
15-20
(4.6-6.1)
20-50
(6.1-15.2)
50-75
(15.2-22.9)
75-100
(22.9-30.5)
100-150
(30.5-45.7)
150-200
(45.7-61.0)
L
S
21⁄8
21⁄8
S
21⁄8
21⁄8
L
11⁄8
11⁄8
S
21⁄8
25⁄8
L
11⁄8
11⁄8
S
25⁄8
25⁄8
L
11⁄8
11⁄8
S
25⁄8
25⁄8
L
13⁄8
13⁄8
S
25⁄8
31⁄8
7
044
054
⁄
⁄
8
*
*
*
*
*
*
7
8
*
064;
7
Modules 124A,
124B, 134A
⁄
8
8
21⁄8
11⁄8
25⁄8
†
11⁄8
25⁄8
†
11⁄8
25⁄8
†
13⁄8
31⁄8
*
13⁄8
31⁄8
*
074;
Module 134B
7
⁄
21⁄8
21⁄8
11⁄8
11⁄8
25⁄8
25⁄8
†
11⁄8
13⁄8
25⁄8
31⁄8
†
13⁄8
13⁄8
31⁄8
31⁄8
*
13⁄8
13⁄8
31⁄8
31⁄8
*
13⁄8
15⁄8
31⁄8
35⁄8
*
084
11⁄8
†
*
*
*
*
LEGEND
design criteria may allow selection of smaller pipe sizes, but at a
penalty of decreased system capacity and efficiency.
5. Double suction risers may be required if condensing unit is
elevated above the evaporator. See footnotes and double suction
riser table below.
6. Refer to Carrier System Design Manual, E20-II design program,
or ASHRAE Handbook for further information on selecting pipe
sizes for split systems.
7. All pipe sizes are OD inches. Equivalent sizes in millimeters
follow:
CV
L
—
—
—
—
Constant Volume
Liquid Line
S
Suction Line
VAV
Variable Air Volume
*Double suction riser required on all units configurations if condens-
ing unit is elevated above evaporator.
†Double suction riser required on units with factory installed VAV op-
tion or CV units with additional field installed unloader on circuit A1
(lead) compressor if condensing unit is elevated above evaporator.
in.
mm
NOTES:
7
1. Addition of field-installed unloaders on A2 (lag) compressor is not
recommended.
⁄
8
22.2
28.6
34.9
41.3
54.0
66.7
79.4
92.1
11⁄8
13⁄8
15⁄8
21⁄8
25⁄8
31⁄8
35⁄8
2. Piping sizes are based on unit operation above 40 F (4.4 C) satu-
rated suction temperature (SST). When operating below 40 F
(4.4 C), refer to Carrier System Design Manual, E20-IIா piping
design program, or ASHRAE Handbook to select proper line sizes.
3. Pipe sizes are based on the total linear length shown for each
column, plus a 50% allowance for fittings.
4. Suction and liquid line sizing is based on pressure drop equivalent
to 2 F (1.1 C) at nominal rating conditions. Higher pressure drop
Table 9B — Refrigerant Piping Requirements for Double Suction Risers,
38AH044-084 Optional Single-Circuit Units and 38AH124,134
Modular Units (Dual Circuit) — 50 Hz
TOTAL LINEAR LENGTH OF INTERCONNECTING PIPE — FT (M)
UNIT
38AH
15-20
(4.6-6.1)
20-50
(6.1-15.2)
50-75
(15.2-22.9)
75-100
(22.9-30.5)
100-150
(30.5-45.7)
150-200
(45.7-61.0)
A
B
C
A
B
C
A
—
15⁄8
B
—
21⁄8
C
—
25⁄8
A
15⁄8
15⁄8
B
21⁄8
21⁄8
C
25⁄8
25⁄8
A
15⁄8
15⁄8
B
25⁄8
21⁄8
C
25⁄8
25⁄8
A
15⁄8
15⁄8
B
25⁄8
25⁄8
C
25⁄8
31⁄8
044
054
—
—
—
—
—
—
—
—
—
—
—
—
064;
Modules 124A,
124B, 134A
—
—
—
15⁄8
21⁄8
25⁄8
15⁄8
21⁄8
25⁄8
15⁄8
21⁄8
25⁄8
15⁄8
25⁄8
31⁄8
15⁄8
25⁄8
31⁄8
074;
—
—
—
—
—
—
15⁄8
15⁄8
21⁄8
21⁄8
25⁄8
25⁄8
15⁄8
15⁄8
21⁄8
25⁄8
25⁄8
31⁄8
15⁄8
15⁄8
25⁄8
25⁄8
31⁄8
31⁄8
15⁄8
15⁄8
25⁄8
25⁄8
31⁄8
31⁄8
15⁄8
15⁄8
31⁄8
31⁄8
35⁄8
35⁄8
Module 134B
084
LEGEND
Not Required
3. Suction and liquid line sizing is based on pressure drop equivalent
to 2 F (1.1 C) at nominal rating conditions. Higher design pressure
drop criteria may allow selection of smaller pipe sizes but at a pen-
alty of decreased system capacity and efficiency.
4. Refer to Carrier System Design Manual or to E20-II design
programs for further information on selecting pipe sizes for split
systems.
—
—
—
—
—
Pipe A
Pipe B
Pipe C
Suction Riser Without Trap
Suction Riser With Trap
Suction Line to Condensing Unit
NOTES:
1. See Refrigerant Piping Requirements table at top of page to
determine need for double suction risers.
2. Pipe sizes are based on the total linear length, shown for each
column, plus a 50% allowance for fittings.
5. All pipe sizes are OD inches. See Table 9A notes for metric
equivalents.
6. Refer to Fig. 13 for double suction riser construction.
19
LEGEND
TXV
TYP
—
—
Thermostatic Expansion Valve
Typical
NOTE: Lower split first on, last off.
Fig. 14 — Typical Piping Connections for Face Split Coils for 38AH044-084 Dual-Circuit
and 38AH094-134 Units
LEGEND
TXV
TYP
—
—
Thermostatic Expansion Valve
Typical
NOTE: Lower split first on, last off.
Fig. 15 — Typical Piping Connections for Face Split Coils for 38AH044-084
Optional Single-Circuit Units
20
Units 38AH124 and 134 Piping Kit Connections — The
38AH124 and 134 units are delivered with a factory-
supplied suction and liquid piping kit for installation in the
24-in. (610-mm) service space between the 2 unit modules.
The piping kit allows for a common unit side piping con-
nection from the indoor unit to each of the condensing unit
refrigeration circuits. Fittings are provided and shipped in
the control box.
align holes and reinsert screws B. Place horizontal cover on
top of Module 134A end cover with opposite side resting on
the horizontal flange of the installed Module B vertical top
cover piece. Align holes on flange and top cover. Reinsert
screws A through the top cover holes into the end cover. From
within the service space, insert supplied screws up through
the flange and horizontal cover to make a secure connection
between the horizontal and vertical cover pieces.
Insert supplied screws into each of the 2 holes in the ver-
tical side flange of the top cover at each end of the service
space.
Remove the copper tubes from Module 124A or 134A com-
pressor rails. Save the pipe clamps for later use. Cut the
25⁄8-in. (67-mm) suction tube into 2 pieces: 28 in. (711 mm)
and 67 in. (1702 mm). Connect the 2 formed 11⁄8-in.
(29-mm) tubes to the liquid line connection at the liquid valve.
See Fig. 16.
Attach Side Panels — Insert side panels at the ends of the
service space and hook side panel flange over the 2 screws
previously inserted in the top cover flange. Fasten panels to
the corner posts with supplied self-drilling screws, 3 per side.
See Fig. 19.
NOTE: Piping kit is designed to allow air handler connec-
tions to project from either side of the service space.
To prepare condensing unit modules for piping connec-
tion, refer to beginning paragraphs of Step 3 — Make
Refrigeration Piping Connections, page 14.
Connect Tubing from Evaporator to Unit
Two 25⁄8-in. (67-mm) and one 11⁄8-in. (29-mm) elbows are
supplied for piping connections. Fit tubing to ensure proper
installation. All tubes should have equal lengths projecting
beyond unit corner posts. See Fig. 16. Ensure suction tube
is level for oil return requirements.
Protect liquid valves from the heat of brazing.
Braze the liquid and suction lines from the evaporator to
the condensing unit liquid and suction lines. Leak test the
entire system by the pressure method described in the
Carrier Standard Service Techniques Manual, Chapter 1,
Section 1-6. Use R-22 at approximately 25 psig (172 kPa)
backed up with an inert gas to a total pressure not to exceed
245 psig (1689 kPa). If a leak is detected, evacuate and de-
hydrate the system. Follow methods described in the Carrier
Service Manual, Chapter 1, Section 1-7.
Protect liquid valves from the heat of brazing.
Braze the piping connections.
Level the tubes and clamp to the corner posts with factory-
supplied self-drilling screws and pipe clamps removed from
Module 124A or 134A during piping kit removal.
Units 38AH124 and 134 Sheet Metal Trim Kit Installation
— After the units are in place and the piping kit is installed,
install the sheet metal trim kit.
NOTE: Install sheet metal trim kit before connection to air
handler tubing in case the modules must be repositioned to
accommodate the sheet metal installation.
Remove two 43-in. (1092 mm) base rail trim pieces from
Module 124A or 134A base rail. Remove the 3 corner post
bolts from the bottom of each corner post at the service space.
Align the base rail trim piece holes over the bolt holes in the
corner rails. See Fig. 17. Reinsert corner post bolts through
the trim piece into the corner posts.
Attach Top Cover — To attach top cover, proceed as
follows:
For Unit 38AH124, remove screws A from top of each of
4 corner posts at service space. See Fig. 18. Place cover on
top of service space and align top cover slots with corner
post screw holes. Reinsert screws A.
NOTES:
For Unit 38AH134, remove screws A from top of each cor-
ner post on Module 134A and screws B from top of each
corner post on Module 134B. See Fig. 18. Top cover is in
2 pieces: one vertical piece and one horizontal piece. Slide
vertical top cover partly under Module 134B end cover flange;
1. Ensure suction tube is level for oil return requirements.
2. Protect liquid valves from heat of brazing.
Fig. 16 — Units 38AH124 and 134 with Installed
Piping Kit
21
CORNER
SCREWS (2) CORNER
TOP
MODULE
124B
OR 134B
MODULE
124A
POST (4 PER FOR
POST
COVER
MODULE)
MOUNTING (4 PER
FLANGE OR 134A
SIDE PANEL MODULE)
BASE RAIL
BOLTS (6)
CORNER
POST
CORNER POST
FACTORY-SUPPLIED
SELF-DRILLING
SCREWS (4 PER
CORNER POST)
Fig. 17 — Units 38AH124 and 134 with Installed Trim
Kit Rails
24-in. (610-mm)
SERVICE WAY
Fig. 19 — Fully Assembled Piping and Trim Kit
(Unit 38AH134 Shown)
SCREWS A
TOP COVER,
HORIZONTAL
PIECE
TOP COVER,
VERTICAL
PIECE
SCREWS B
VERTICAL
END COVER
FLANGES
TOP COVER
FLANGE
END COVER
(HIDDEN)
24-in. (610-mm)
SERVICE WAY
CORNER MODULE 124B
CORNER MODULE 124A
POST OR 134A
POST
OR 134B
Fig. 18 — Units 38AH124 and 134 with Installed Top
Cover (Unit 38AH134 Shown)
22
MAIN POWER — Units 38AH044-104 have single-point
power connection to simplify field-power wiring (all power
enters at one end). Units 38AH124 and 134 require 2 con-
nection points, one for each module. Units may use copper,
copper-clad aluminum, or aluminum conductors at all volt-
ages. The maximum wire size units can accept per terminal
block is 500 kcmil.
Step 4 — Make Electrical Connections
POWER SUPPLY — Electrical characteristics of available
power supply must agree with unit nameplate rating. Supply
voltage must be within the limits shown in Tables 10A or
10B, 11 and 12. See Table 13 for control circuit data and
Table 14 for fan motor electrical data.
Power must be supplied as shown in Table 15.
IMPORTANT: Operation of unit on improper supply
voltage or with excessive phase imbalance constitutes
abuse and can affect any Carrier warranty.
CONTROL CIRCUIT WIRING — Control circuit wiring is
accomplished with a step-down transformer on voltage des-
ignations 500, 600, and 100 in table below where the pri-
mary voltage is field voltage. For 208/230-v, 3-ph, 60-Hz
units, ensure that the transformer primary is wired properly
for the voltage which will be applied. All control wiring must
comply with applicable local and national codes. The safety
circuits are 24 v on all units. The safety circuit voltage is
created with a step-down transformer where main control
voltage is the transformer primary voltage.
FIELD POWER CONNECTIONS — All power wiring must
comply with applicable local and national codes. Install field-
supplied, branch circuit safety disconnect(s) of a type that
can be locked off/open. Disconnects must be located within
sight of, and readily accessible from, the unit in compliance
with NEC (National Electrical Code) (U.S.A. Standard)
Article 440-14.
See Table 13 for control circuit information.
All field power enters the unit through a hole in the con-
trol box shelf. Refer to Fig. 20-28 for field wiring details.
Table 10A — Electrical Data — 50/60 Hz (38AH044-084 Dual-Circuit Units)
STANDARD UNIT
COMPRESSOR*
A1 B1
Compressor
A1/B1
Supply Voltage†
Voltage
Nameplate
V-Ph-Hz
38AH
044
MCA
MOCP
ICF
Designation
Min
Max
RLA
LRA
RLA
LRA
Model No.
500
208/230-3-60
460-3-60
187
414
518
342
198
342
325
254
508
632
418
254
440
367
179.4
91.3
225
100
100
125
225
100
125
434.7
218.6
162.4
241.2
296.7
219.6
165.9
67.9
34.6
28.8
34.6
67.9
34.6
33.3
345
173
120
191
207
173
115
67.9
34.6
28.8
34.6
67.9
34.6
33.3
345
173
120
191
207
173
115
600
100
575-3-60
78.4
200
06E4250/250
380-3-60
230-3-50
380/415-3-50
346-3-50
93.5
800 (PW)
900
180.2
91.5
300 (PW)
100.0
500
208/230-3-60
460-3-60
187
414
518
342
342
325
254
508
632
418
440
367
206.6
102.4
88.0
107.1
102.7
107.0
250
125
125
150
125
150
535.7
268.6
206.4
297.2
269.6
198.9
67.9
34.6
28.8
34.6
34.6
33.3
345
173
120
191
173
115
89.7
43.6
36.5
45.5
43.6
44.9
446
223
164
247
223
148
600
100
575-3-60
054
064
074
084
06E4250/265
06E8265/275
06E8275/299
06E8299/299
200
380-3-60
380/415-3-50
346-3-50
900
300 (PW)
500
208/230-3-60
460-3-60
187
414
518
342
342
325
254
508
632
418
440
367
249.3
115.5
100.6
126.9
114.1
129.8
350
150
125
175
150
175
617.5
307.6
226.1
341.1
335.6
230.5
89.7
43.6
36.5
45.5
43.6
44.9
446
223
164
247
223
148
106.4
46.8
40.4
52.6
46.8
53.8
506
253
176
280
280
168
600
100
575-3-60
380-3-60
200
900
380/415-3-50
346-3-50
300 (PW)
500
208/230-3-60
460-3-60
187
414
518
342
342
325
254
508
632
418
440
367
330.5
148.6
132.2
174.5
143.0
170.8
450
200
175
250
200
250
829.0
408.2
336.8
458.0
403.8
300.4
106.4
46.8
40.4
52.6
46.8
53.8
506
253
176
280
280
168
147.4
65.4
57.1
78.8
65.4
79.5
690
345
276
382
345
229
600
100
575-3-60
380-3-60
200
900
380/415-3-50
346-3-50
300 (PW)
500
208/230-3-60
460-3-60
187
414
518
342
342
325
254
508
632
418
440
367
371.5
167.2
148.9
200.7
167.6
205.3
500
225
200
250
225
250
870.0
426.8
353.5
484.2
428.4
334.9
147.4
65.4
57.1
78.8
65.4
79.5
690
345
276
382
345
229
147.4
65.4
57.1
78.8
65.4
79.5
690
345
276
382
345
229
600
100
575-3-60
380-3-60
200
900
380/415-3-50
346-3-50
300 (PW)
See page 24 for Legend and Notes.
23
Table 10B — Electrical Data — 50/60 Hz (38AH044-084 Optional Single-Circuit Units)
OPTIONAL SINGLE-CIRCUIT UNIT
COMPRESSOR*
A1 A2
Compressor
Supply Voltage
Voltage
Nameplate
V-Ph-Hz
38AH
044
A1/A2
Model No.
MCA
MOCP
ICF
Designation
Min
Max
RLA
LRA
RLA
LRA
500
208/230-3-60
460-3-60
187
414
518
342
198
342
325
254
508
632
418
254
440
367
179.4
91.3
225
100
100
125
225
100
125
434.7
218.6
162.4
241.2
296.7
219.6
165.9
67.9
34.6
28.8
34.6
67.9
34.6
33.3
345
173
120
191
207
173
115
67.9
34.6
28.8
34.6
67.9
34.6
33.3
345
173
120
191
207
173
115
600
100
575-3-60
78.4
200
06E4250/250
380-3-60
230-3-50
380/415-3-50
346-3-50
93.5
800 (PW)
900
180.2
91.5
300 (PW)
100.0
500
208/230-3-60
460-3-60
187
414
518
342
342
325
254
508
632
418
440
367
206.6
102.4
88.0
107.1
102.7
107.0
250
125
125
150
125
150
535.7
268.6
206.4
297.2
269.6
198.9
89.7
43.6
36.5
45.5
43.6
44.9
446
223
164
247
223
148
67.9
34.6
28.8
34.6
34.6
33.3
345
173
120
191
173
115
600
100
575-3-60
054
064
074
084
06E4265/250
06E8275/265
06E8299/275
200
380-3-60
380/415-3-50
346-3-50
900
300 (PW)
500
208/230-3-60
460-3-60
187
414
518
342
342
325
254
508
632
418
440
367
249.3
115.5
100.6
126.9
115.7
129.8
350
150
125
175
150
175
617.5
307.6
226.1
341.1
335.6
230.5
106.4
46.8
40.4
52.6
46.8
53.8
506
253
176
280
280
168
89.7
43.6
36.5
45.5
43.6
44.9
446
223
164
247
223
148
600
100
575-3-60
380-3-60
200
900
380/415-3-50
346-3-50
300 (PW)
500
208/230-3-60
460-3-60
187
414
518
342
342
325
254
508
632
418
440
367
330.5
148.6
132.2
174.5
143.0
170.8
450
200
175
250
200
250
829.0
408.2
336.8
458.0
403.8
300.4
147.4
65.4
57.1
78.8
65.4
79.5
690
345
276
382
345
229
106.4
46.8
40.4
52.6
46.8
53.8
506
253
176
280
280
168
600
100
575-3-60
380-3-60
200
900
380/415-3-50
346-3-50
300 (PW)
500
208/230-3-60
460-3-60
187
414
518
342
342
325
254
508
632
418
440
367
371.5
167.2
148.9
200.7
167.6
205.3
500
225
200
250
225
250
870.0
426.8
353.5
484.2
428.4
334.9
147.4
65.4
57.1
78.8
65.4
79.5
690
345
276
382
345
229
147.4
65.4
57.1
78.8
65.4
79.5
690
345
276
382
345
229
600
100
575-3-60
06E8299/299
LEGEND
200
380-3-60
380/415-3-50
346-3-50
900
300 (PW)
*All compressors are across-the-line start only except 38AH044
230 v, 3-phase, 50 Hz; and all 346 v, 3-phase, 50 Hz.
FLA
ICF
—
—
Full Load Amps
†Units are suitable for use on electrical systems where voltage sup-
plied to unit terminals is within listed minimum to maximum limits.
Maximum Instantaneous Current Flow During Starting.
(The point in the starting sequence where the sum of
the LRA for the starting compressors, plus the total RLA
for all running compressors, plus the FLA for all running
fan motors is maximum.)
NOTES:
1. Maximum allowable phase imbalance: voltage - 2%; amps - 10%.
2. Maximum incoming wire size for terminal block is 500 kcmil.
kcmil
LRA
Max
—
—
—
—
Thousand Circular Mils
Locked Rotor Amps
Maximum
MCA
Minimum Circuit Amps (used for sizing; complies with
National Electrical Code [NEC] [U.S.A. Standard],
section 430-24).
Min
MOCP
—
—
Minimum
Maximum Overcurrent Protection (used for sizing dis-
connect; complies with NEC Article 440, Section 22).
Rated Load Amps
RLA
PW
—
—
Part Wind Only
24
Table 11 — Electrical Data — 50/60 Hz (Units 38AH094,104)
COMPRESSOR†
A2 B1
RLA LRA RLA LRA RLA LRA RLA LRA
SUPPLY
UNIT
VOLTAGE
NAMEPLATE
V-Ph-Hz
VOLTAGE*
MCA MOCP ICF
A1
B2
38AH DESIGNATION
Min
187
414
518
342
342
325
187
414
518
342
342
325
Max
253
506
633
418
440
380
253
506
633
418
440
380
500
600
208/230-3-60
460-3-60
398.5
183.1
160.9
209.1
183.6
212.9
399.4
196.3
168.0
205.9
196.7
205.6
500
225
200
250
225
250
450
225
200
250
225
250
897 106.4 506
67.9
34.6
28.8
34.6
34.6
33.3
67.9
34.6
28.8
34.6
34.6
33.3
345 147.7 690
—
—
—
—
443
366
493
444
343
722
361
286
396
363
298
46.8 253
40.4 176
52.6 280
46.8 280
53.8 168
89.7 446
43.6 223
36.5 164
45.5 247
43.6 223
44.9 148
173
120
191
173
115
345
173
120
191
173
229
65.4
57.1
78.8
65.4
79.5
89.7
43.6
36.5
45.5
43.6
44.9
345
276
382
345
229
446
223
164
247
223
148
100
575-3-60
—
—
094
200
380-3-60
—
—
900
380/415-3-50
346-3-50
—
—
300 (PW)
500
—
—
208/230-3-60
460-3-60
89.7
43.6
36.5
45.5
43.6
49.9
446
223
164
247
223
148
600
100
575-3-60
104
200
380-3-60
900
380/415-3-50
346-3-50
300 (PW)
LEGEND
*Units are suitable for use on electrical systems where voltage sup-
plied to unit terminals is within listed minimum to maximum limits.
†All compressors are across-the-line start only except 346-V, 3-ph,
50-Hz units.
—
FLA
ICF
—
—
—
Not Applicable
Full Load Amps
Maximum Instantaneous Current Flow During Starting.
(The point in the starting sequence where the sum of
the LRA for the starting compressors, plus the total RLA
for all running compressors, plus the FLA for all running
fan motors is maximum.)
Thousand Circular Mils
Locked Rotor Amps
NOTES:
1. Maximum allowable phase imbalance: voltage - 2%; amps - 10%.
2. Maximum incoming wire size for terminal block is 500 kcmil.
3. For units 38AH094 and 104 compressor model numbers, see table
below:
kcmil
LRA
MCA
—
—
—
Minimum Circuit Amps (used for sizing; complies with
National Electrical Code [NEC] [U.S.A. Standard],
section 430-24).
UNIT
094
A2
104
38AH
MOCP
RLA
—
—
Maximum Overcurrent Protection (used for sizing
disconnect; complies with NEC [U.S.A. Standard],
section 440-22).
CKT
A1
B1
A1
A2
B1
B2
MODEL
NO. 06E
−275 −250 −299 −265 −250 −265 −265
Rated Load Amps
25
Table 12 — Electrical Data — 50/60 Hz (Units 38AH124, 134)
COMPRESSOR†
A1 A2
SUPPLY
UNIT
38AH
COMPRESSOR
A1/A2
VOLTAGE
NAMEPLATE
V-Ph-Hz
VOLTAGE*
MCA
MOCP
ICF
DESIGNATION
MODULE
MODEL NO.
Min
187
414
518
342
342
325
187
414
518
342
342
325
Max
254
508
632
418
440
367
254
508
632
418
440
367
RLA
617.5 106.4
LRA
506
253
176
280
280
168
690
345
276
382
345
229
RLA
LRA
446
223
164
247
223
148
506
253
176
280
280
168
500
208/230-3-60
460-3-60
249.3
115.5
100.6
126.9
115.7
129.8
330.5
148.6
132.2
174.5
149.0
170.8
350
150
125
175
150
175
450
200
175
250
200
250
89.7
43.6
36.5
45.5
43.6
44.9
106.4
46.8
40.4
52.6
46.8
53.8
600
307.6
226.1
341.1
335.6
230.5
46.8
40.4
52.6
46.8
53.8
124A
124B
134A
100
575-3-60
06E8275/
265
200
380-3-60
900
380/415-3-50
346-3-50
300 (PW)
500
208/230-3-60
460-3-60
829.0 147.4
600
408.2
336.8
458.0
403.8
300.4
65.4
57.1
78.8
65.4
79.5
100
575-3-60
06E8299/
275
134B
200
380-3-60
900
380/415-3-50
346-3-50
300 (PW)
LEGEND
*Units are suitable for use on electrical systems where voltage sup-
plied to unit terminals is within listed minimum to maximum limits.
†All compressors are across-the-line start only except 346-v, 3-ph,
50 Hz unit.
FLA
ICF
—
—
Full Load Amps
Maximum Instantaneous Current Flow During Starting.
(The point in the starting sequence where the sum of
the LRA for the starting compressors, plus the total RLA
for all running compressors, plus the FLA for all running
fan motors is maximum.)
Thousand Circular Mils
Locked Rotor Amps
NOTES:
1. Maximum allowable phase imbalance: voltage - 2%; amps - 10%.
2. Maximum incoming wire size for terminal block is 500 kcmil.
kcmil
LRA
—
—
—
MCA
Minimum Circuit Amps (used for sizing; complies with
National Electrical Code [NEC] [U.S.A. Standard],
section 430-24).
Maximum Overcurrent Protection (used for sizing
disconnect; complies with NEC [U.S.A. Standard],
section 440- 22).
Part Wind
Rated Load Amps
MOCP
—
PW
RLA
—
—
Table 13 — Control Circuit Electrical Data — 50/60 Hz
UNIT POWER
V-Ph-Hz
CONTROL POWER
UNIT
DESIGNATION
AMPS
V-Ph-Hz
Min
Max
−500
−600
−100
−200
−800
−900
−300
208/230-3-60
460-3-60
115-1-60
115-1-60
115-1-60
230-1-60
230-1-50
230-1-50
200-1-50
103
103
103
207
207
207
180
127
127
127
253
253
253
220
4.1
4.1
4.1
2.0
2.0
2.0
2.4
575-3-60
380-3-60
230-3-50
380/415-3-50
346-3-50
NOTE: Units 38AH124 and 134 have 2 control boxes per unit, one in each module.
26
Table 14 — Fan Motor Electrical Data
CONDENSER FAN
UNIT
38AH
Nameplate
V-Ph-Hz
Hp
(kW)
Total
kW
Qty
(No.*) FLA Each
(No.*) LRA Each
208/230-3-60
460-3-60
(1,2) 5.5 (3,4) 6.6
(1,2) 2.8 (3,4) 3.3
(1-4) 3.4
(1,2) 30.0 (3,4) 31.6
(1,2) 30.0 (3,4) 31.6
(1-4) 30.0
575-3-60
1
044
380-3-60
4
6.2
(1-4) 3.9
(1-4) 20.9
(0.746)
230-3-50
(1,2) 5.5 (3,4) 6.8
(1-4) 3.4
(1,2) 30.0 (3,4) 31.6
(1-4) 30.0
380/415-3-50
346-3-50
(1-4) 4.4
(1-4) 20.9
208/230-3-60
460-3-60
(1,2) 5.5 (3,4) 6.6
(1,2) 2.8 (3,4) 3.3
(1-4) 3.4
(1,2) 30.0 (3,4) 31.6
(1,2) 30.0 (3,4) 31.6
(1-4) 30.0
575-3-60
1
054
064
074
084
094
104
4
4
6
6
6
6
6.2
6.2
9.3
9.3
9.4
9.5
(0.746)
380-3-60
(1-4) 3.9
(1-4) 20.9
380/415-3-50
346-3-50
(1-4) 3.4
(1-4) 30.0
(1-4) 4.4
(1-4) 20.9
208/230-3-60
460-3-60
(1,2) 5.5 (3,4) 6.6
(1,2) 2.8 (3,4) 3.3
(1-4) 3.4
(1,2) 30.0 (3,4) 31.6
(1,2) 30.0 (3,4) 31.6
(1-4) 30.0
575-3-60
1
(0.746)
380-3-60
(1-4) 3.9
(1-4) 20.9
380/415-3-50
346-3-50
(1-4) 3.4
(1-4) 30.0
(1-4) 4.4
(1-4) 20.9
208/230-3-60
460-3-60
(1,2) 5.5 (3-6) 6.6
(1,2) 2.8 (3-6) 3.3
(1-6) 3.4
(1,2) 30.0 (3-6) 31.6
(1,2) 30.0 (3-6) 31.6
(1-6) 30.0
575-3-60
1
(0.746)
380-3-60
(1-6) 3.9
(1-6) 20.9
380/415-3-50
346-3-50
(1-6) 3.4
(1-6) 30.0
(1-6) 4.4
(1-6) 20.9
208/230-3-60
460-3-60
(1,2) 5.5 (3-6) 6.6
(1,2) 2.8 (3-6) 3.3
(1-6) 3.4
(1,2) 30.0 (3-6) 31.6
(1,2) 30.0 (3-6) 31.6
(1-6) 30.0
575-3-60
1
(0.746)
380-3-60
(1-6) 3.9
(1-6) 20.9
380/415-3-50
346-3-50
(1-6) 3.4
(1-6) 30.0
(1-6) 4.4
(1-6) 20.9
208/230-3-60
460-3-60
(1,2) 5.5 (3-6) 6.6
(1-2) 2.8 (3-6) 3.3
(1-6) 3.4
(1,2) 30.0 (3-6) 31.6
(1,2) 30.0 (3-6) 31.6
(1-6) 30.0
575-3-60
1
(0.746)
380-3-60
(1-6) 3.9
(1-6) 20.9
380/415-3-50
346-3-50
(1-6) 3.4
(1-6) 30.0
(1-6) 4.4
(1-6) 20.9
208/230-3-60
460-3-60
(1,2) 5.5 (3-6) 6.6
(1,2) 2.8 (3-6) 3.3
(1-6) 3.4
(1,2) 30.0 (3-6) 31.6
(1,2) 30.0 (3-6) 31.6
(1-6) 30.0
575-3-60
1
(0.746)
380-3-60
(1-6) 3.9
(1-6) 20.9
380/415-3-50
346-3-50
(1-6) 3.4
(1-6) 30.0
(1-6) 4.4
(1-6) 20.9
UNIT 38AH
MODULE
208/230-3-60
460-3-60
(1,2) 5.5 (3,4) 6.6
(1,2) 2.8 (3,4) 3.3
(1-4) 3.4
(1,2) 30.0 (3,4) 31.6
(1,2) 30.0 (3,4) 31.6
(1-4) 30.0
124A
124B
134A
575-3-60
1
4
6
6.4
9.2
(0.746)
380-3-60
(1-4) 3.9
(1-4) 20.9
380/415-3-50
346-3-50
(1-4) 3.4
(1-4) 30.0
(1-4) 4.4
(1-4) 20.9
208/230-3-60
460-3-60
(1,2) 5.5 (3-6) 6.6
(1,2) 2.8 (3-6) 3.3
(1-6) 3.4
(1,2) 30.0 (3-6) 31.6
(1,2) 30.0 (3-6) 31.6
(1-6) 30.0
575-3-60
1
134B
(0.746)
380-3-60
(1-6) 3.9
(1-6) 20.9
380/415-3-50
346-3-50
(1-6) 3.4
(1-6) 30.0
(1-6) 4.4
(1-6) 20.9
LEGEND
*Refers to condenser fans by position: See circled numbers on top
views of units in Fig. 1-6.
FLA
LRA
—
—
Full Load Amps
Locked Rotor Amps
NOTE: All fans are protected by a single circuit breaker.
27
Internal 33CSUCE-06 relay contacts are rated for 1 amp/24 vac.
*To control heating device and provide automatic indoor-
fan operation on heating.
†Jumper removed only when separate 24-v trans-
former power source is used to power the 33CSUCE-06
relay pack.
**Field-supplied.
NOTES:
0.13 amp at 230 vac). Thermostats must have a
LEGEND
1. Liquid line solenoid valve LLS-A is used for so-
lenoid drop on circuitA. Liquid line solenoid valve
LLS-B is used for solenoid drop for circuit B.
2. Solenoid drop is a safety feature which pre-
vents refrigerant migration to the compressor dur-
ing the OFF cycle. It is recommended on all
systems and required on systems where piping
exceeds 75 ft (22.9 m) in length.
minimum pilot duty rating of 300 va (2.5 amps at
120 vac and 1.3 amps at 230 vac).
AWG
CR
—
—
—
—
—
—
—
—
American Wire Gage
Control Relay
8. Replacement of factory wires must be with type
105 C wire or its equivalent.
HD
Heating Device
IFC
IFR
kcmil
LLS
NEC
Indoor-Fan Contactor
Indoor-Fan Relay
9. Field-supplied liquid line solenoid valves installed
at the evaporator are required on all units.
10. Units have 175 va of power available for field-
installed accessories.
Thousand Circular Mils
Liquid Line Solenoid
National Electrical Code
(U.S.A. Standard)
3. The 33CSUCE-06 relay pack requires 10 va.
4. Factory wiring is in accordance with NEC; field
modifications or additions must be in compli-
ance with all applicable codes.
5. Wiring for field power supply must be rated
75 C minimum. Use copper, copper-clad alumi-
num, or aluminum conductors. Maximum in-
coming wire size for each terminal block is
500 kcmil.
11. To minimize voltage drop, the following wire sizes
are recommended:
R
—
Heating Relay (field-
supplied 24-v sealed coil,
10 va maximum rating)
Reversing Valve
Terminal Block
Factory Wiring
LENGTH —
Ft (M)
INSULATED WIRE — AWG
(35 C Minimum)
RV
TB
—
—
Up to 50
(15.2)
50-75
(15.2-22.9)
More Than 75
(22.9)
No. 18
No. 16
No. 14
Field Wiring
6. Terminal blocks TB3 and TB4 are for external
field control connections. Control connections
are to be Class 1 wiring.
7. Field-supplied components (IFC, LLS-A, and
LLS-B) must have a maximum sealed coil rat-
ing of 30 va each (0.25 amp at 120 vac and
Fig. 20 — Field Wiring, One 2-Stage Thermostat — 38AH044-084 Dual-Circuit Units
28
Internal 33CSUCE-06 relay contacts are rated for 1 amp/24 vac.
*To control heating device and provide automatic indoor-
fan operation on heating.
†Jumper removed only when separate 24-v trans-
former power source is used to power the 33CSUCE-06
relay pack.
**Field-supplied.
NOTES:
LEGEND
at 230 vac). Thermostats must have a minimum pilot
duty rating of 300 va (2.5 amps at 120 vac and
1.3 amps at 230 vac).
1. Liquid line solenoid valves LLS-A1 and A2 are used
for solenoid drops.
AWG
CR
—
—
—
—
—
—
—
—
American Wire Gage
Control Relay
2. Solenoid drop is a safety feature which prevents
refrigerant migration to the compressor during
the OFF cycle. It is recommended on all systems
and required on systems where piping exceeds
75 ft (22.9 m) in length.
3. The 33CSUCE-01 relay pack requires 10 va.
4. Factory wiring is in accordance with NEC; field modi-
fications or additions must be in compliance with
all applicable codes.
5. Wiring for field power supply must be rated 75 C
minimum. Use copper, copper-clad aluminum, or
aluminum conductors. Maximum incoming wire size
for each terminal block is 500 kcmil.
6. Terminal blocks are for external field control con-
nections. Control connections are to be Class 1
wiring.
8. Replacement of factory wires must be with type
105 C wire or its equivalent.
HD
Heating Device
IFC
IFR
kcmil
LLS
NEC
Indoor-Fan Contactor
Indoor-Fan Relay
9. Field-supplied liquid line solenoid valves installed at
the evaporator are required on all units.
10. Units have 175 va of power available for field-
installed accessories.
11. To minimize voltage drop, the following wire sizes are
recommended:
Thousand Circular Mils
Liquid Line Solenoid
National Electrical Code
(U.S.A. Standard)
R
—
Heating Relay (field-
supplied 24-v sealed coil,
10 va maximum rating)
Reversing Valve
Terminal Block
Factory Wiring
LENGTH —
Ft (M)
INSULATED WIRE — AWG
(35 C Minimum)
RV
TB
—
—
Up to 50
(15.2)
50-75
(15.2-22.9)
More Than 75
(22.9)
No. 18
No. 16
No. 14
Field Wiring
7. Field-supplied components (IFC, LLS-A1, and
LLS-A2) must have a maximum sealed coil rating
of 30 va each (0.25 amp at 120 vac and 0.13 amp
Fig. 21 — Field Wiring, One 2-Stage Thermostat — 38AH044-084 Optional Single-Circuit Units
29
Internal 33CSUCE-06 relay contacts are rated for 1 amp/24 vac.
*To control heating device and provide automatic indoor-
fan operation on heating.
†Jumper removed only when separate 24-v trans-
former power source is used to power the 33CSUCE-06
relay pack.
**Field-supplied.
NOTES:
1. Liquid line solenoid valve LLS-A1 is used for solenoid drop
on circuit A. Liquid line solenoid valve LLS-B1 is used for
solenoid drop for circuit B.
2. Solenoid drop is a safety feature which prevents refrigerant
migration to the compressor during the OFF cycle. It is rec-
ommended on all systems and required on systems where
piping exceeds 75 ft (22.9 m) in length.
3. The 33CSUCE-06 relay pack requires 10 va.
4. Factory wiring is in accordance with NEC; field modifications
or additions must be in compliance with all applicable codes.
5. Wiring for field power supply must be rated 75 C mini-
mum. Use copper, copper-clad aluminum, or aluminum con-
ductors. Maximum incoming wire size for each terminal block
is 500 kcmil.
6. Terminal blocks are for external field control connections. Con-
trol connections must be Class 1 wiring.
7. Field-supplied components (IFC, LLS-A1, and LLS-B1) must
have a maximum sealed coil rating of 30 va each (0.25 amp
at 120 vac and 0.13 amp at 230 vac). Thermostats must have
a minimum pilot duty rating as follows:
8. Replacement of factory wires must be with
LEGEND
type 105 C wire or its equivalent.
9. Field-supplied liquid line solenoid valves in-
stalled at the evaporator are required on all
units.
AWG
CR
—
—
—
—
—
—
—
—
American Wire Gage
Control Relay
HD
Heating Device
IFC
IFR
kcmil
LLS
NEC
Indoor-Fan Contactor
Indoor-Fan Relay
10. Units 38AH094 has 140 va and unit 38AH104
has 130 va of power available for field-
installed accessories.
11. To minimize voltage drop, the following wire
sizes are recommended:
Thousand Circular Mils
Liquid Line Solenoid
National Electrical Code
(U.S.A. Standard)
R
—
Heating Relay (field-
supplied 24-v sealed coil,
10 va maximum rating)
Reversing Valve
Terminal Block
Factory Wiring
INSULATED WIRE —
LENGTH —
AWG
RV
TB
—
—
Ft (M)
(35 C Minimum)
Up to 50
No. 18
(15.2)
Field Wiring
50-75
(15.2-22.9)
No. 16
VA
More Than 75
(22.9)
38AH
094
AMPS
VAC
No. 14
(Ea Stage)
2.29
1.15
2.70
1.35
120
240
120
240
275
104
325
Fig. 22 — Field Wiring, One 2-Stage Thermostat — Units 38AH094 and 104
30
Internal 33CSUCE-06 relay contacts are rated for 1 amp/24 vac.
*Jumper removed only when separate 24-v trans-
former power source is used to power the 33CSUCE-06
relay pack.
†Field-supplied.
NOTES:
1. Liquid line solenoid valves LLS-A1 and A2 are used
for solenoid drop on Module 124A or 134A on cir-
cuit A. Liquid line solenoid valves LLS-B1 and B2
are used for solenoid drop for Module 124B or 134B.
Solenoid drop is a safety feature which prevents
refrigerant migration to the compressor during
the OFF cycle. It is recommended on all systems
and required on systems where piping exceeds
75 ft (22.9 m) in length.
2. Disconnect black wire from CR2 terminal 6; cap loose
end and secure. Connect new field-supplied wire
from CR2 terminal 6 to TB3 terminal 1 on module
124B or 134B.
3. The 33CSUCE-06 relay pack requires 10 va.
4. Factory wiring is in accordance with NEC; field modi-
fications or additions must be in compliance with
all applicable codes.
5. Wiring for field power supply must be rated 75 C
minimum. Use copper, copper-clad aluminum, or
aluminum conductors. Maximum incoming wire size
for each terminal block is 500 kcmil.
7. Field-supplied components (IFC, LLS-A1,A2, and
LEGEND
LLS-B1,B2) must have a maximum sealed coil
rating of 30 va each (0.25 amp at 120 vac and
0.13 amp at 230 vac). Thermostats must have a
minimum pilot duty rating of 300 va (2.5 amps at
120 vac).
AWG
C
—
—
—
American Wire Gage
Compressor Contactor
Capacity Control Pressure
Switch
Control Relay
Heating Device
Indoor-Fan Contactor
Indoor-Fan Relay
Thousand Circular Mils
Liquid Line Solenoid
National Electrical Code
(U.S.A. Standard)
Heating Relay (field-
supplied 24-v sealed coil,
10 va maximum rating)
Reversing Valve
CCPS
CR
—
—
—
—
—
—
—
8. Replacement of factory wires must be with type
HD
IFC
105 C wire or its equivalent.
IFR
9. Field-supplied liquid line solenoid valves installed
at the evaporator are required on all units.
10. Units have 175 va of power available for field-
installed accessories.
kcmil
LLS
NEC
11. To minimize voltage drop, the following wire sizes
R
—
are recommended:
LENGTH —
Ft (M)
INSULATED WIRE — AWG
(35 C Minimum)
RV
—
—
—
—
SDR
TB
Solenoid Drop Relay
Terminal Block
Timer Relay
Factory Wiring
Field Wiring
Up to 50
(15.2)
50-75
(15.2-22.9)
More Than 75
(22.9)
No. 18
No. 16
No. 14
TR
6. Terminal blocks (TB3) are for external field control
connections. Control connections must be Class 1
wiring.
Fig. 23 — Field Wiring, One 2-Stage Thermostat — Units 38AH124 and 134
31
*Field-supplied.
NOTES:
1. Factory wiring is in accordance with NEC; field modifications or addi-
tions must be in compliance with all applicable codes.
2. Wiring for field power supply must be rated 75 C minimum. Use cop-
per, copper-clad aluminum, or aluminum conductors. Maximum
incoming wire size for each terminal block is 500 kcmil.
3. Terminal blocks TB3 and TB4 are for external field control connec-
tions. Control connections are to be Class 1 wiring.
4. Field-supplied components (IFC, LLS-A, and LLS-B) must have a maxi-
mum sealed coil rating of 30 va each (.25 amp at 120 vac, .13 amp at
230 vac). AHMS IFC-AUX must have a minimum pilot duty rating of
200 va (1.7 amps at 120 vac, 0.9 amps at 230 vac) each.
5. Replacement of factory wires must be with type 105 C wire or its
equivalent.
LEGEND
AHMS
—
Air Handler Motor
Starter
SDR
TB
—
—
—
Solenoid Drop Relay
Terminal Block
TBX
Terminal Block for Variable
Air Volume Units
Timer Motor
AUX
C
—
—
—
—
—
—
—
—
Auxiliary
Compressor Contactor
Fuse
FU
TM
—
—
—
—
GND
IFC
Equipment Ground
Indoor Fan Control
TR
Timer Relay
TRAN
Transformer
kcmil
LLS
NEC
Thousand Circular Mils
Liquid Line Solenoid
National Electrical Code
(U.S.A. Standard)
U
Unloader Solenoid
6. Field-supplied liquid line solenoid valves installed at the evaporator are
required on all units.
7. Units have 175 va of power available for field-installed accessories.
Factory Wiring
Field Wiring
Fig. 24 — Field Wiring, Single ModuPanel™ Control, 38AH044-084 Dual-Circuit Units
*Field-supplied.
NOTES:
1. Factory wiring is in accordance with NEC; field modifications or addi-
tions must be in compliance with all applicable codes.
2. Wiring for field power supply must be rated 75 C minimum. Use cop-
per, copper-clad aluminum, or aluminum conductors. Maximum in com-
ing wire size for each terminal block is 500 kcmil.
LEGEND
3. Terminal blocks TB3, TBX1, and TBX2 are for external field control con-
nections. Control connections are to be Class 1 wiring.
4. Field-supplied components (IFC, LLS-A1, and LLS-A2) must have a
maximum sealed coil rating of 30 va each (0.25 amp at 120 vac,
13 amp at 230 vac). AHMS IFC-AUX must have minimum pilot duty
rating of 400 va each (3.4 amps at 120 vac, 1.8 amps at 230 vac) each.
5. Replacement of factory wires must be with type 105 C wire or its
equivalent.
AHMS
—
Air Handler Motor
Starter
SDR
—
—
—
Solenoid Drop Relay
Terminal Block
Terminal Block for
Variable Air Volume
Units
TB
TBX
AUX
C
—
—
—
—
—
—
—
—
Auxiliary
Compressor Contactor
Fuse
FU
GND
IFC
Equipment Ground
Indoor Fan Control
Thousand Circular Mils
Liquid Line Solenoid
National Electrical Code
(U.S.A. Standard)
TM
TR
TRAN
U
—
—
—
—
Timer Motor
Timer Relay
kcmil
LLS
NEC
Transformer
Unloader Solenoid
6. Field-supplied liquid line solenoid valves installed at the evaporator are
required on all units.
Factory Wiring
Field Wiring
7. Control has 175 va of power available for field-installed accessories.
Fig. 25 — Field Wiring, Single ModuPanel™ Control, 38AH044-084 Optional Single-Circuit Units
*Field-supplied.
NOTES:
1. Factory wiring is in accordance with NEC. Field modifications
or additions must be in compliance with all applicable codes.
2. Wiring for field power supply must be rated 75 C minimum. Use
copper, copper-clad aluminum, or aluminum conductors. Maxi-
mum incoming wire size for each terminal block is 500 kcmil.
3. Terminal blocks TB3, TB4, TBX1, and TBX2 are for external
field control connections. Control connections are to be
Class 1 wiring.
LEGEND
4. Field-supplied components (IFC, LLS-A1, A2, B1, and B2) must
have a maximum sealed coil rating of 30 va each (0.25 amp at
120 vac, 0.13 amp at 230 vac). AHMS IFC-AUX contact must
have minimum pilot duty rating of 325 va each (2.7 amps at
120 vac, 1.4 amps at 230 vac).
AHMS
AUX
C
—
—
—
—
—
—
—
—
—
Air Handler Motor Starter
SDR
—
—
—
Solenoid Drop Relay
Terminal Block
Auxiliary
TB
Compressor Contactor
Fuse
TBX
Terminal Block for Variable
Air Volume Units
Timer Motor
FU
GND
IFC
kcmil
LLS
NEC
Equipment Ground
Indoor Fan Control
Thousand Circular Mils
Liquid Line Solenoid
National Electrical Code
(U.S.A. Standard)
TM
TR
TRAN
U
—
—
—
—
5. Replacement of factory wires must be with type 105 C wire or
its equivalent.
Timer Relay
Transformer
Unloader Solenoid
6. Field-supplied liquid line solenoid valves installed at the evapo-
rator are required on all units.
Factory Wiring
Field Wiring
7. Control has 25 va of power available for field-installed
accessories.
Fig. 26 — Field Wiring, Single ModuPanel™ Control, Unit 38AH094
34
*Field-supplied.
NOTES:
1. Factory wiring is in accordance with NEC. Field modifications or
additions must be in compliance with all applicable codes.
2. Wiring for field power supply must be rated 75 C minimum. Use
copper, copper-clad aluminum, or aluminum conductors. Maxi-
mum incoming wire size for each terminal block is 500 kcmil.
3. Terminal blocks TB3, TB4, TBX1, and TBX2 are for external field
control connections. Control connections are to be Class 1 wiring.
4. Field-supplied components (IFC, LLS-A1, A2, B1, and B2) must
have a maximum sealed coil rating of 30 va each (0.25 amp at
120 vac, 0.13 amp at 230 vac). AHMS IFC-AUX contact must have
minimum pilot duty rating of 375 va each (3.1 amps at 120 vac,
1.6 amps at 230 vac).
LEGEND
AHMS
AUX
C
—
—
—
—
—
—
—
—
—
Air Handler Motor Starter
TB
TBX
—
—
Terminal Block
Terminal Block for
Variable Air Volume
Units
Auxiliary
Compressor Contactor
Fuse
FU
GND
IFC
kcmil
LLS
NEC
Equipment Ground
Indoor Fan Control
Thousand Circular Mils
Liquid Line Solenoid
National Electrical Code
(U.S.A. Standard)
Solenoid Drop Relay
TM
TR
TRAN
U
—
—
—
—
Timer Motor
Timer Relay
Transformer
Unloader Solenoid
Factory Wiring
5. Replacement of factory wires must be with type 105 C wire or its
equivalent.
Field Wiring
SDR
—
6. Field-supplied liquid line solenoid valves installed at the evapora-
tor are required on all units.
7. Control has 35 va of power available for field-installed accessories.
Fig. 27 — Field Wiring, Single ModuPanel™ Control, Unit 38AH104
35
*Field-supplied.
NOTES:
1. Factory wiring is in accordance with NEC. Field modifications or
additions must be in compliance with all applicable codes.
2. Wiring for field power supply must be rated 75 C minimum. Use
copper, copper-clad aluminum, or aluminum conductors. Maxi-
mum incoming wire size for each terminal block is 500 kcmil.
3. Terminal blocks TB3 and TBX1 are for external field control con-
nections. Control connections are to be Class 1 wiring.
4. Field-supplied components (IFC, LLS-A1 and A2) must have a maxi-
mum sealed coil rating of 30 va each (0.25 amp at 120 vac,
0.13 amp at 230 vac). AHMS IFC-AUX contact must have mini-
mum pilot duty rating of 400 va each (3.4 amps at 120 vac,
1.8 amps at 230 vac).
LEGEND
AHMS
AUX
C
—
—
—
—
—
—
—
—
—
Air Handler Motor Starter
SDR
TB
TBX
—
—
—
Solenoid Drop Relay
Terminal Block
Auxilliary
Compressor Contactor
Fuse
Terminal Block for Variable
Air Volume Units
Timer Motor
FU
GND
IFC
kcmil
LLS
NEC
Equipment Ground
Indoor Fan Control
Thousand Circular Mils
Liquid Line Solenoid
National Electrical Code
(U.S.A. Standard)
TM
TR
TRAN
U
—
—
—
—
5. Replacement of factory wires must be with type 105 C wire or its
equivalent.
Timer Relay
Transformer
6. Field-supplied liquid line solenoid valves installed at the evapora-
tor are required on all units.
7. Units have 175 va of power available for field-installed
accessories.
Unloader Solenoid
Factory Wiring
Field Wiring
Fig. 28 — Field Wiring, Single ModuPanel™ Control, Units 38AH124 and 134
36
Table 15 — Main Power Connection and Control Circuit Wiring
MAIN POWER CONNECTION
CONTROL CIRCUIT
Electrical
Characteristics
(V-Ph-Hz)
Qty
Terminal
Blocks
Qty
Max Wire
Size
(kcmil)
Control Power
(V)
Safety Circuit
(V)
Parallel
Conductors*
208/230-3-60
1
1
1
1
1
6
3
6
3
3
500
500
500
500
500
115†
115†
230
24
24
24
24
24
460-3-60
575-3-60
230-3-50
380-3-60
380/415-3-50
230
346-3-50
200
LEGEND
kcmil
*Conductors are from the safety disconnect.
†Control power is accomplished with a step-down transformer where primary voltage is field voltage.
—
Thousand Circular Mils
2. Backseat (open) compressor suction and discharge shut-
off valves. Close valves one turn to allow refrigerant pres-
sure to reach the test gages.
Step 5 — Install Accessories
LOW-AMBIENT OPERATION
Units 38AH044-084, 124, and 134 — If operating tempera-
tures below 55 F (13 C) are expected, Motormaster III fan
motor control is recommended. Refer to separate installa-
tion instructions for low-ambient operation guidelines.
3. Open liquid line service valves.
4. Check tightness of all electrical connections.
5. Oil should be visible in the compressor sight glasses.
See Fig. 29. An acceptable oil level in the compressor
1
1
Units 38AH094 and 104 — If operating temperatures below
45 F (7 C) are expected, Motormaster III fan motor control
is recommended. Refer to separate installation instructions
for low-ambient operation guidelines.
is from ⁄8 to ⁄3 of sight glass. Adjust the oil level as
required. No oil should be removed unless the crank-
case heater has been energized for at least 24 hours. See
Preliminary Oil Charge section on page 38, for Carrier-
approved oils.
MISCELLANEOUS ACCESSORIES — For applications
requiring special accessories, the following packages are
available: condenser coil hail guard package, gage panel,
unloader package, unloader conversion kits, sound reduc-
tion package, condenser coil protective grilles, compressor
security grilles, ModuPanel™ control, and thermostat trans-
former relay package.
6. Electrical power source must agree with unit
nameplate.
Crankcase heaters on all units are wired into the
control circuit, so they are always operable as long
as the main power supply disconnect is on (closed),
even if any safety device is open. Compressor heat-
ers must be on for 24 hours prior to the start-up of
any compressor.
PRE-START-UP
IMPORTANT: Before beginning Pre-Start-Up or Start-
Up, review Start-Up Checklist at the back of this pub-
lication. The Checklist assures proper start-up of a unit
and provides a record of unit condition, application re-
quirements, system information, and operation at ini-
tial start-up.
7. Crankcase heaters must be firmly locked into compres-
sors, and must be on for 24 hours prior to start-up.
8. Fan motors are 3-phase. Check rotation of fans during
first start-up check. Fan rotation is clockwise as viewed
from top of unit. If fan is not turning clockwise, reverse
2 of the power wires.
9. Check compressor suspension. On units 38AH044-084,
124, and 134, snubber washers (for noise suppression)
can be moved with finger pressure. On units 38AH094
and 104, rails allow compressors to float freely on com-
pressor rail springs.
10. On 38AH074,084 single-circuit units and Module
38AH134B, ensure that the packaging block located be-
tween the oil equalization tube and the compressor cross-
brace has been removed.
Do not attempt to start the air-conditioning system until
following checks have been completed.
System Check
1. Check all system components, including the air-
handling equipment. Consult manufacturer’s instruc-
tions. If the unit has field-installed accessories, be sure
all are properly installed and wired correctly. Refer to
unit wiring diagrams.
37
DISCHARGE
GAS THERMOSTAT
HIGH-
FAN CYCLING
DISCHARGE GAS
CYLINDER
HEADS
OIL PRESSURE SWITCH AND
CAPACITY CONTROL
PRESSURE SWITCH CAPILLARIES
PRESSURE PRESSURE SWITCH THERMOSTAT
SWITCH
MUFFLER
SIGHT
GLASS
OIL
EQUALIZER
LINE
LOW-
PRESSURE
SWITCH
RAIL
CRANKCASE
HEATER
SIGHT
GLASS
MOUNTING
SPRING
(HIDDEN)
PRESSURE RELIEF
VALVE
NOTE: Units 38AH044-084 and 38AH124, 134 compressors are pan
mounted. Units 38AH094 and 104 compressors are mounted on rails.
Fig. 29 — 06E Compressors, Typical
8. If any leaks are detected, evacuate and dehydrate as pre-
viously outlined in Step 3 — Make Refrigerant Piping
Connections, page 14.
START-UP
Compressor crankcase heaters must be on for 24 hours
before start-up. To energize the crankcase heaters, set the
space thermostat above the ambient so there will be no de-
mand for cooling. Close the field disconnect and turn on the
fan circuit breakers. Leave the compressor circuit breakers
off/open. The crankcase heaters are now energized.
Preliminary Oil Charge — Each compressor is fac-
tory charged with oil (see Table 3A, 3B, 4A, or 4B). When
oil is checked at start-up, it may be necessary to add or re-
move oil to bring it to the proper level. One recommended
oil level adjustment method is as follows:
Preliminary Checks
ADD OIL — Close suction shutoff valve and pump down
crankcase to 2 psig (14 kPa). (Low-pressure cutout must be
jumped.) Wait a few minutes and repeat until pressure re-
mains steady at 2 psig (14 kPa). Remove oil fill plug above
the oil level sight glass, add oil through plug hole, and re-
place plug. Run compressor for 20 minutes and check oil
level.
1. Ensure that compressor service valves are backseated.
2. Verify that each compressor on units 38AH044-084, 124,
and 134 floats freely on its mounting springs. Verify that
each compressor on units 38AH094 and 104 floats freely
on its rails.
3. Check that electric power supply agrees with unit name-
plate data.
4. Verify that compressor crankcase heaters are securely in
place.
5. Check that compressor crankcase heaters have been on at
least 24 hours.
IMPORTANT: For units with 2 compressors per re-
frigeration circuit, both compressors must be running
to adjust the oil level. Two oil level equalizer lines
between compressors distribute the oil to each
compressor.
6. Note that compressor oil level is visible in the sight glass.
7. Recheck for leaks using same procedure as previously out-
lined in Step 3 — Make Refrigerant Piping Connections,
page 14.
38
NOTE: Use only Carrier approved compressor oil. Ap-
proved sources are: Petroleum Specialties Inc. (Cryol 150A),
Texaco, Inc. (Capella WF-32-150), and Witco Chemical Co.
(Suniso 3GS). Do not reuse oil that has been drained out, or
oil that has been exposed to atmosphere.
compressor B1. Start-up of compressor B1 is delayed from
12 seconds to 51⁄2 minutes. (Circuit B of unit 38AH094 has
only one compressor.)
Each circuit’s lead compressor start-up is controlled by
the unit control timer. The circuit’s lag compressor start-up
is controlled by the D-D2 timer contacts and capacity
control pressure switches (CCPSs) which monitor compres-
sor suction pressure. The circuit’s lag compressor will start
approximately 21⁄2 minutes after a call for cooling if com-
pressor pressure is above CCPS set point.
REMOVE OIL — Pump down compressor to 2 psig
(14 kPag). Loosen the 1⁄4-in. (6.4-mm) pipe plug at the com-
pressor base and allow the oil to seep out past the threads of
the plug.
NOTE: The crankcase will be slightly pressurized. Do not
remove the plug, or the entire oil charge will be lost.
38AH124,134 UNITS — Start-up of the lead circuit
(Module 124A or 134A) lead compressor A1 (Table 16) is
delayed from 12 seconds to 51⁄2 minutes from the time the
call for cooling is initiated by TC1. Lag compressor A2 is
controlled by D-D2 timer contacts and capacity control pres-
sure switches (CCPSs) which monitor compressor suction
pressure. The lag compressor starts approximately 21⁄2 min-
utes after the lead compressor starts if the suction pressure
is above the CCPS set point.
After the lead circuit (Module 124A or 134A) lead com-
pressor A1 (Table 16) starts, close the TC2 thermostat to start
the lag circuit (Module 124B or 134B) lead compressor (A1).
Lag circuit compressor A1 start-up is delayed from 12 sec-
onds to 51⁄2 minutes from the time the call for cooling is
initiated by TC2. Lag compressor A2 is controlled by D-D2
timer contacts and CCPSs which monitor compressor suc-
tion pressure. Lag compressor A2 starts approximately 21⁄2
minutes after lead compressor A1 starts if the suction pres-
sure is above the CCPS set point.
Small amounts of oil can be removed through the oil pump
discharge connection while the compressor is running.
Preliminary Charge — Refer to GTAC II (General Train-
ing Air Conditioning), Module 5, Charging, Recovery,
Recycling, and Reclamation for charging procedures. Using
the liquid charging method and charging by weight proce-
dure, charge each circuit with the amount of R-22 listed in
Table 3A, 3B, 4A, or 4B.
Never charge liquid into the low-pressure side of sys-
tem. Do not overcharge. During charging or removal of
refrigerant, be sure indoor-fan system is operating.
Start Unit — The field disconnect is closed, the fan cir-
cuit breaker is closed, and the space thermostats are set above
ambient so that there is no demand for cooling. Only the
crankcase heaters are energized.
Adjust Refrigerant Charge
Close the compressor circuit breakers and then reset both
space thermostats below ambient so that a call for stage one
cooling is ensured. Lead refrigeration circuit ther-
mostat TC1 must be set to call for cooling at a lower tem-
perature than lag refrigeration circuit thermostat TC2.
See Table 16 for lead/lag circuits on all units. Now set TC2
for cooling.
Never charge liquid into the low-pressure side of sys-
tem. Do not overcharge. During charging or removal of
refrigerant, be sure indoor-fan system is operating.
With all fans operating, and all compressors on the cir-
cuit being serviced operating at full capacity, adjust the
refrigerant charge in accordance with the unit charging charts
located on the inside of the control box doors and in
Fig. 30-43. Charge vapor into compressor low-side service
port located above oil pump crankshaft housing. Measure
pressure at the liquid line service valve, making sure a Schrader
depressor is used if required. Also, measure liquid line tem-
perature as close to the liquid service valve as possible. Add
charge until the pressure and temperature conditions of the
charging chart curve are met. If liquid pressure and tempera-
ture point fall above curve, add charge. If liquid pressure
and temperature point fall below curve, reduce the charge
until the conditions match the curve.
If the sight glass at location A (Fig. 11 and 12) is cloudy,
check refrigerant charge again. Ensure all fans and com-
pressors on the circuit being serviced are operating. Also
ensure maximum allowable liquid lift has not been
exceeded.
If the sight glass at location A is clear and the sight
glass at location B is cloudy, a restriction exists in the
line between the 2 sight glasses. Check for a plugged filter
drier or partially open solenoid valve. Replace or repair, as
needed.
NOTE: Do not use circuit breakers to start and stop the com-
pressor except in an emergency.
38AH044-084 DUAL-CIRCUIT UNITS — Start-up of lead
compressor A1 (Table 16) will be delayed from 12 seconds
to 51⁄2 minutes from the time the call for cooling is initiated
by TC1. After the lead compressor starts, close the TC2 ther-
mostat to start lag circuit compressor B1. Compressor B1
will start a minimum of 60 seconds after thermostat TC2 is
closed.
38AH044-084 OPTIONAL SINGLE CIRCUIT UNITS —
Start-up of lead compressor A1 (Table 16) is delayed from
12 seconds to 51⁄2 minutes from the time the call for cooling
is initiated by TC1. Closure of TC2 will actuate LLS-A2.
Lag compressor A2 is controlled by D-D2 timer contacts and
capacity control pressure switches (CCPSs) which monitor
compressor suction pressure. The lag compressor starts ap-
proximately 21⁄2 minutes after the lead compressor starts if
the suction pressure is above the CCPS set point.
38AH094,104 UNITS — Start-up of lead circuit A,
compressor A1 (Table 16) is delayed from 12 seconds to
51⁄2 minutes from the time the call for cooling is initiated.
After lead circuit A, compressor A1 starts, close refrig-
eration circuit thermostat TC2 to start lag circuit B, lead
39
Table 16 — Index of Lead/Lag Circuits and Compressors
UNIT
38AH
044-084
STD
044-084
OPT
094
104
124
134
Module
124A
A1
Module
134A
A1
LEAD CIRCUIT
A
A
A
A
Compressor, Lead
Compressor; Lag
A1
*
A1
A2
A1
A2
A1
A2
A2
A2
Module
124B
A1
Module
134B
A1
LAG CIRCUIT
B
†
B
B
Compressor, Lead
Compressor; Lag
B1
*
B1
*
B1
B2
A2
A2
LEGEND
OPT
STD
—
—
Optional Single-Circuit Units
Standard Dual-Circuit Units
*Circuit has only one compressor.
†Units have only one circuit.
electrically actuated unloaders are installed, energize the so-
lenoid to unload the compressor. Recheck the compressor
oil level as described in Check Compressor Oil Level above.
Return unloader to original setting after checks are
complete.
Check Compressor Oil Level — After adjusting the
refrigerant charge, allow each circuit to run fully loaded for
1
1
20 minutes. Running oil level should be ⁄8 to ⁄3 up on the
sight glass. Stop the compressors at the field power supply
disconnect and check the crankcase oil level. Add oil only if
necessary to bring the oil into view in the sight glass. If oil
is added, run the circuit for an additional 10 minutes, then
stop and check oil level. If the level remains low, check the
piping system for proper design for oil return; also, check
the system for leaks.
UNITS 38AH094,104 — For this minimum load check, the
lead compressor (A1, B1) of each refrigeration circuit is un-
loaded. See Table 16. The lag compressor (A2, B2 [38AH104
only]) of each refrigeration circuit must not be operating.
Unload the compressor(s) by turning the control set point
adjustment nut counterclockwise until the adjustment nut stops.
The unloader is now at 0 psig (0 kPag) set point. If electri-
cally actuated unloaders are installed, energize the solenoid
to unload the compressor.
Return unloader to original setting after checks are
complete.
If the initial check shows too much oil (too high in the
sight glass) remove oil to proper level. See Preliminary Oil
Charge for proper procedure for adding and removing oil.
When the above checks are complete, repeat the proce-
dure with the unit operating at minimum load conditions.
UNITS 38AH044-084,124, AND 134 — For this minimum
load check, run the lead compressor of each refrigeration cir-
cuit fully unloaded with the lag compressor not operating.
Unload the compressor(s) by turning the control set point
adjustment nut counterclockwise until the adjustment nut
stops. The unloader is now at 0 psig (0 kPag) set point. If
Final Checks — Ensure all safety controls are operat-
ing, control panel covers are on, and the service panels are
in place.
40
Fig. 30 — Charging Chart — Unit 38AH044; 50/60 Hz — Dual Circuit
Fig. 31 — Charging Chart — Unit 38AH054; 50/60 Hz — Dual Circuit
41
Fig. 32 — Charging Chart — Unit 38AH064; 50/60 Hz — Dual Circuit
Fig. 33 — Charging Chart — Unit 38AH074; 50/60 Hz — Dual Circuit
42
Fig. 34 — Charging Chart — Unit 38AH084; 50/60 Hz — Dual Circuit
Fig. 36 — Charging Chart — Unit 38AH054;
50/60 Hz — Optional Single Circuit
Fig. 35 — Charging Chart — Unit 38AH044;
50/60 Hz — Optional Single Circuit
43
Fig. 37 — Charging Chart — Unit 38AH064;
50/60 Hz — Optional Single Circuit
Fig. 38 — Charging Chart — Unit 38AH074;
50/60 Hz — Optional Single Circuit
Fig. 39 — Charging Chart — Unit 38AH084;
50/60 Hz — Optional Single Circuit
44
Fig. 40 — Charging Chart — Unit 38AH094; 50/60 Hz
Fig. 41 — Charging Chart — Unit 38AH104; 50/60 Hz
Fig. 42 — Charging Chart — Modules 124A, 124B,
and 134A; 50/60 Hz
Fig. 43 — Charging Chart — Module 134B;
50/60 Hz
45
The heater is held in place by a clip and bracket and must be
tightly connected since exposure to the air causes the heater
to burn out. Each heater is wired into the compressor control
circuit through a relay which energizes only when the com-
pressor is off. The heater keeps the oil at a temperature that
prevents excessive absorption of refrigerant during shut-
down periods.
SERVICE
ELECTRIC SHOCK HAZARD
Turn off all power to unit before servicing.
The ON-OFF switch on control panel
does not shut off control power; use field
disconnect.
Energize the crankcase heaters when the unit is not run-
ning except during prolonged shutdown or servicing. Ener-
gize the heaters at least 24 hours before restarting the unit
after prolonged shutdown.
Coil Cleaning — Clean the coils with a vacuum cleaner,
compressed air, water, or a non-wire bristle brush.
Refrigerant Circuit
TIME GUARD FUNCTION — This function prevents com-
pressors from short-cycling.
LEAK TESTING — Units are shipped with a holding charge
of R-22 (see Table 3A, 3B, 4A, or 4B) and should be under
sufficient pressure to conduct a leak test. If there is no pres-
sure in the system, introduce enough nitrogen to search
for the leak. Repair the leak using good refrigeration prac-
tices. After leaks are repaired, system must be evacuated and
dehydrated using methods described in GTAC II , Module 4,
System Dehydration.
Fan Motor Protection — Fan motors are protected
by a single circuit breaker for all motors.
Head Pressure Control — Head pressure control re-
duces condenser capacity under low-ambient conditions. This
is achieved by fan cycling control (standard, all units) and
Motormaster III control accessory (field installed).
REFRIGERANT CHARGE (Refer to Table 3A, 3B, 4A, or
4B) — At the liquid line connection point on each circuit is
a factory-installed liquid line service valve. On each
FAN CYCLING — All condensing units have standard pro-
vision for fully automatic intermediate season head pressure
control through fan cycling (see Table 17).
1
valve is a ⁄4-in. Schrader connection for charging liquid
38AH044-084 Dual-Circuit Units — Fans no. 3 and 4 are
cycled by pressure control on all units. On 38AH074 and
084, fans no. 5 and 6 are also cycled by pressure control.
38AH044-084 Optional Single Circuit Units — Fans no. 3
and 4 are cycled by pressure control on all units. On 38AH074
and 084, fans no. 5 and 6 are cycled by an air-temperature
switch located in the bottom shelf of the control box.
Units 38AH094,104 — Fans no. 3 through 6 are cycled by
pressure control.
Units 38AH124,134 — Fans no. 3 and 4 on each unit mod-
ule are cycled by pressure control. On module 134B only,
fans no. 5 and 6 are cycled by an air-temperature switch lo-
cated in the bottom shelf of the control box.
Pressure control is achieved via a fan cycling pressure switch
located on the cylinder head of the unit or circuit lead com-
pressor (see Fig. 29).
The air-temperature switch used to control fans no. 5 and
6 on 38AH074,084 optional single-circuit units and on mod-
ule 134B is closed and cycles the fans on when the ambient-
air temperature is above 70 F (21 C).
refrigerant.
Charging with Unit Off and Evacuated — Close liquid
line service valve before charging. Weigh in charge shown
in Table 3A, 3B, 4A, or 4B. Open liquid line service valve;
start unit and allow it to run several minutes fully loaded.
Check for a clear sight glass. Be sure clear condition is liq-
uid and not vapor. Complete charging the unit in accordance
with Start-Up, Adjust Refrigerant Charge, page 39.
Charging with Unit Running — If charge is to be added while
unit is operating, it is necessary to have all condenser fans
and compressors operating. It may be necessary to block con-
denser coils at low-ambient temperatures to raise condens-
ing pressure to approximately 280 psig (1931 kPag) to turn
all condenser fans on. Do not totally block a coil to do this.
Partially block all coils in uniform pattern. Charge
vapor into compressor low-side service port located above
oil pump crankshaft housing. Charge each circuit until sight
glass shows clear liquid.
Troubleshooting — Refer to Troubleshooting chart lo-
cated at back of book.
Oil Pressure Safety Switch (OPS) — An oil pres-
sure safety switch for each of the independent refrigerant
circuits shuts off the compressor in that circuit if oil pressure
is not established at start-up or maintained during operation.
If the OPS stops the unit, determine and correct the cause
before restarting the unit. Failure to do so constitutes equip-
ment abuse and could affect the warranty.
Table 17 — Fan Cycling Control — Psig (kPag)
Control by Pressure*
Switch Opens
Switch Closes
± 10 (69)
160 (1103)
255 (1758)
*On all units, fans no. 3 and 4; also on unit 38AH074, 084 (dual-
circuit units only) and 38AH094,104, fans no. 5 and 6.
NOTE: Fans no. 1 and 2 are noncycling. Units 38AH074,084 optional
Compressor Motor Protection
single-circuit units and module 134B fans no.
5
and
6
are
CIRCUIT BREAKER — A manual reset, calibrated trip cir-
cuit breaker for each compressor protects against overcur-
rent. Do not bypass connections or increase size of circuit
breaker for any reason. If trouble occurs, determine the cause
and correct it before resetting the breaker.
cycled by an air-temperature switch which operates above 70 F
(21 C) ambient-air temperature.
DISCHARGE GAS THERMOSTAT — A sensor in the
cylinder head of each compressor (Fig. 29) shuts down the
compressor if excessively high discharge gas temperature is
sensed. If the discharge gas thermostat shuts the unit down,
it may be reset by the thermostat or power disconnect switch.
38AH044-064,
Modules 124A, 124B,
134A
38AH074-104,
Module 134B
CRANKCASE HEATER (See Fig. 29) — Each compressor
has an electric crankcase heater located in the bottom cover.
46
Winter Start Control — A21⁄2-minute low-pressure switch
(LPS) bypass function in the timer prevents nuisance LPS
trips during start-up in low-ambient conditions.
38AH094,104 — Capacity control is achieved by a pressure-
actuated cylinder bank unloader on the lead compressor
(A1, B1) on each of the 2 refrigeration circuits. As the cool-
ing load decreases and the suction pressure drops, the un-
loader actuates at the pre-set suction pressure and unloads
the cylinder bank. (See Fig. 44 and Table 20.) The unloading
of the compressor cylinder bank has no effect on the opera-
tion of the circuit lag compressor (A2, B2 [except 38AH094,
circuit B]) which is controlled by fixed setting capacity con-
trol pressure switches (CCPSs) as follows:
High-Pressure Switch — This switch has nonadjust-
able settings. Figure 29 shows connection on a cylinder head.
See Table 18 for pressure switch settings.
NOTE: High-pressure switch must be removed from cylin-
der head before removing compressor from the unit.
TO CHECK — Slowly close the discharge shutoff valve un-
til the compressor shuts down. This should be at approxi-
mately 426 psig (2935 kPag). Slowly open the valve. When
the pressure drops to approximately 320 psig (2205 kPag),
the pressure switch resets. To reenergize the control circuit,
manually switch the fan circuit breaker off and then on. The
compressor starts again under Time Guard controls.
CUT-IN —
Psi (kPa)
CUTOUT —
Psi (kPa)
CCPS 1
CCPS 2
83 (572)
80 (551)
63 (531)
53 (365)
CCPS
—
Capacity Control Pressure Switch
Low-Pressure Switch — The low-pressure switch (LPS)
has fixed nonadjustable settings. It is located at the pump
end of the compressor above the bearing head. See Table 18
for pressure switch settings.
Pressure Relief — High-side pressure relief is pro-
vided by a fusible plug in the liquid line at the service valve.
For low-side pressure relief, a fusible plug is inserted in the
side of the accumulator (all units except 38AH044-084 dual-
circuit, constant-volume units). See Fig. 45. The 38AH044-
084 dual-circuit, constant-volume units have a fusible plug
in the suction tubing. A pressure relief valve installed on the
compressor relieves at 450 psig (3102 kPag) (see Fig. 1-6).
TO CHECK — Slowly close the suction cut-off valve and
allow the compressor to shut down. This should occur at
approximately 27 psig (186 kPag). Slowly open the valve.
The compressor restarts under Time Guard control when the
pressure builds to approximately 67 psig (462 kPag).
Table 18 — Pressure Switch Settings,
Psig (kPag)
SWITCH
High
CUTOUT
CUT-IN
426 ±
7
320 ± 20
(2205 ± 138)
(2935 ± 48)
27 ±
4
67 ±
7
Low
(186 ± 28)
(462 ± 48)
Capacity Control
38AH044-084 DUAL-CIRCUIT UNITS — Capacity con-
trol is achieved by a pressure-actuated cylinder bank un-
loader on lead compressor A1. As the cooling load decreases
and the suction pressure drops, the unloader actuates at the
pre-set suction pressure and unloads the cylinder bank. (See
Fig. 44 and Table 19A.) The unloading of the compressor
cylinder bank has no effect on the operation of lag compres-
sor B2, which is controlled by TC2.
38AH044-084 SINGLE-CIRCUIT UNITS AND MOD-
ULES 124A, 124B, 134A, AND 134B — Capacity control
is achieved by a pressure-actuated cylinder bank unloader
on lead compressor A1. See Table 16. As the cooling load
decreases and the suction pressure drops, the unloader
actuates at the pre-set suction pressure and unloads the cyl-
inder bank. (See Fig. 44 and Table 19B and 20.) Lag com-
pressorA2 is controlled by fixed setting capacity control pressure
switches (CCPSs) as follows:
CUT-IN —
Psi (kPa)
CUTOUT —
Psi (kPa)
Unloader Settings
CCPS 1
CCPS 2
83 (572)
80 (551)
63 (531)
53 (365)
Unload, psig (kPag)
Load, psig (kPag)
56 (386)
76 (524)
CCPS
—
Capacity Control Pressure Switch
*Unloader location.
Fig. 44 — Unloader Location and Settings
If suction pressure continues to drop after lead compres-
sor A1 unloads and lag compressor A2 is operating, A2 will
stop operating when the suction pressure drops to the CCPS
cutout point.
47
Table 19A — One 2-Stage Thermostat Capacity
Control for 38AH044-084 Dual-Circuit Units
Table 20 — One 2-Stage Thermostat Capacity
Control for 38AH094-134 Units
QUANTITY OF LOADED
SYSTEM
QUANTITY OF LOADED
SYSTEM
CAPACITY
(%)
UNIT
38AH
COMPRESSOR CYLINDERS
COMPRESSOR CYLINDERS
UNIT
38AH
CAPACITY
(%)
Circuit
A
Circuit
B
Ckt A
Ckt B
Total
Total
10
10
10
10
8
6
4
2
0
0
0
0
16
14
12
10
8
100
85
4
2
4
2
4
4
0
0
8
6
4
2
100
75
70*
55
044
054
50
25
094
104
44
6
4
6
4
33
4
2
2
4
2
6
6
4
0
0
10
8
100
79
59
42
21
22
6*
4
10
8
12
12
10
6
22
20
18
16
12
10
6
100
91
82
73
55
45
27
18
18
9†
2
8
10
6
6
4
2
6
4
2
6
6
6
0
0
0
12
10
8*
6
100
84
68
48
32
16
6
6
4
064
074
084
0
6
4
0
4
4
0
4
4
2*
2†
0
2
6
4
2
6
4
2
6
6
6
0
0
0
12
10
8*
6
100
86
72
43
29
15
12
10
10
12
12
10
10
10
8*
6
24
22
20
18
16
14
12
10
6
100
92
83
75*
67
58*
50
42
25
17
8*
8*
4
6
6
2*
124
6
4
2
6
4
2
6
6
6
0
0
0
12
10
8*
6
100
83
66
50
33
17
6
4
6
6
0
4
0
4
2
4
2*
0
2*
12
12
12
10
10
10
8*
6
24
22
20
18
16
14
12
10
6
100
92
83
75*
67
58*
50
42
25
17
8*
10
10
*Requires units with VAV (variable air volume) factory-supplied
option.
8*
NOTE: Units have 2 independent refrigeration circuits. Circuit A is lead
circuit.
6
6
134
6
4
6
6
0
Table 19B — One 2-Stage Thermostat Capacity
Control for 38AH044-084 Optional Single-Circuit Units
4
0
4
2
2*
0
*Requires VAV (variable air volume) unit or accessory unloader(s) field
installed on circuit lead compressor. Lead compressor is identified in
Table 16, page 40.
SYSTEM
UNIT
38AH
QUANTITY OF
CAPACITY
(%)
LOADED CYLINDERS
†Requires field-installed accessory unloader on circuit lead compres-
sor. Lead compressor is identified in Table 16, page 40.
8
6
4
2
100
75
50
25
044
054
NOTES:
1. Temperatures calculated with the minimum number of fans oper-
ating per circuit.
10
8
100
81
2. See Table 16, page 40, for information on lead and lag circuits.
6
60
6
56
4
37
2*
19*
CONTROL SET POINT — Control set point (cylinder load
point) is adjustable from 0 to 85 psig (0 to 586 kPag).
To adjust the set point, turn the control set point adjust-
ment nut clockwise to bottom stop. (See Fig. 46.) In this
position, load-up set point is 85 psig (586 kPag). Turn
adjustment counterclockwise to desired control set point.
Every full turn clockwise decreases the load-up set point by
7.5 psig (52 kPag).
12
10
8
100
82
64
56
36
18
064
074
084
6
4
2†
12
10
8
100
81
62
57
38
19
6
4
PRESSURE DIFFERENTIAL — Pressure differential
(difference between cylinder load and unload points) is
adjustable from 6 to 22 psig (41 to 152 kPag). To adjust,
turn pressure differential adjustment screw counterclock-
wise to back stop position. The differential pressure is now
adjusted to 6 psig (41 kPag). Turn the adjustment screw clock-
wise to adjust the differential pressure. Every full clockwise
turn increases the differential by 1.5 psig (10 kPag).
2†
12
10
8
100
83
66
50
33
17
6
4
2†
*Requires accessory unloader on lead 06E-265 compressor (A1).
†Requires VAV (variable air volume) factory-installed option or ac-
cessory unloader.
48
CONDENSER
COIL
FUSIBLE
PLUG
SUCTION
LINE
ACCUMULATOR
DISCHARGE
LINE
COMPRESSOR RAIL
Fig. 45 — Accumulator and Fusible Plug
Timer Functions — (See Timer Cycle, Fig. 47.) Each
refrigeration circuit is controlled by an independent timer
which allows for the independent operation of each refrig-
eration circuit.
Fig. 46 — Pressure-Actuated Capacity Control Valve
CONTROL
NOTE: Unit 38AH044-084 optional single-circuit units have
one timer which controls the lead compressor. Lag compres-
sor is controlled by CCPS (capacity control pressure switch).
Sequence of Operation — Units are controlled with
electromechanical components. Each refrigeration circuit
(except 38AH044-084 optional single-circuit units) is oper-
ated by an independent timer which controls the operation
sequence of each circuit.
SWITCH A — The timer is energized through contacts A-A1
or A-A2. This establishes the Time Guard function which
prevents compressor short-cycling. Start of compressor is
delayed approximately 5.5 minutes after shutdown.
On a call for cooling, first stage cooling thermostat TC1
closes. Condenser fans and timer (TM) are energized. After
approximately 7 seconds, timer contacts E-E1 close.
Approximately 12 seconds after TC1 closes, normally-open
timer contacts B-B1 close for 1 second. This energizes
compressor A1 contacts CA1 and starts the compressor. At
the same time, solenoid drop relays (SDRs) and liquid line
solenoid valve no. 1 (LLS-A for 38AH044-084 dual-circuit
units; LLS-A1 for all other units) open, and timer relay
no. 1 (TR2) is energized. Normally open TR2 contacts close,
completing a circuit around B-B1 and through compressor
A1 contactors to maintain compressor operation when B-B1
contacts open. Contacts E-E1 remain closed for approxi-
mately 40 seconds to bypass the oil pressure switch (OPS).
If oil pressure is insufficient when contacts E-E1 open, the
compressor stops, the timer cycles off, and the control cir-
cuit locks out. At start-up, timer contacts D-D1 are closed,
bypassing low-pressure relay contacts LPR-A for 21⁄2 min-
utes. This provides a winter start-up feature.
SWITCH B — The compressor is initially energized through
contacts B-B1.
SWITCH D — Contacts D-D1 provide a 21⁄2-minute bypass
of the low-pressure switch at start-up for winter-start con-
trol. On 38AH044-084 optional single-circuit units, contacts
D-D2 control start-up of compressor A2.
SWITCH E — Contacts E-E1 provide a 40-second bypass
of the oil pressure switch at start-up. If oil pressure does not
build to the required minimum pressure in 40 seconds, the
compressor shuts down and the control circuit locks out.
On 38AH044-084 dual-circuit and 38AH094,104 units, lag
circuit B start-up is delayed 60 seconds after a call for cool-
ing is made to the circuit. This prevents compressor(s) in
both lead and lag circuits from starting at the same time.
Control Circuit Reset — The control circuit locks out
if the unit shuts down because of low oil pressure, high
discharge gas temperature (DGT), or excessive high-side pres-
sure. To reset the control circuit, open and close the fan
circuit breaker (FCB). This resets the timer, and the unit
restarts under Time Guard control. At start-up, if the low-
pressure switch (LPS) does not close after 21⁄2 minutes, the
unit shuts down. When the pressure builds enough for the
LPS to cut in, the control circuit is energized automatically
and start-up proceeds under Time Guard control.
Approximately 21⁄2 minutes after TC1 closes, timer con-
tacts D-D1 open and D-D2 close. If pressure is insufficient
to close the low-pressure switch, the low-pressure switch
relay is open, the compressor shuts down, and the Time Guard
control is initiated. (Time Guard control prevents compres-
sor from restarting for 5 minutes after the demand for cool-
ing is satisfied.)
49
38AH044-084 DUAL-CIRCUIT UNITS; 38AH094,104 —
If circuit A operation is insufficient for the cooling require-
ments, the thermostat second stage TC2 closes to bring cir-
cuit B on-line for cooling. This circuit follows the same se-
quence of operation as the lead circuit, except a
60-second time delay relay (TDR) delays compressor start-up
for 60 seconds after the call for cooling.
38AH044-084 OPTIONAL SINGLE-CIRCUIT UNITS: MOD-
ULES 124A, 124B, 134A, AND 134B
NOTE: This sequence of operation assumes that 2 thermo-
stats control units 38AH124 or 134 with one thermostat con-
trolling each module.
If compressor A1 is insufficient for the cooling require-
ments, the thermostat second stage closes, which opens the
liquid line solenoid valve LLS-A2. Compressor A2 starts only
after D-D2 contacts in the timer close and the suction pres-
sure is sufficient to close the capacity control switches.
NOTE: Black denotes closed contacts.
Fig. 47 — Timer Cycle
Unit Control Box — (See Fig. 48.) Viewed facing com-
pressors, the control box is at left end of the unit. All in-
coming power enters through the control box. The control
box contains power components and electronic controls. Outer
panels are hinged and latched for easy opening. Remove screws
to remove inner panels. Outer panels can be held open for
service and inspection by using door retainer on each panel.
Remove bottom pin from door retainer assembly, swing re-
tainer out horizontally, and engage pin in one of the retainer
ears and the hinge assembly.
ALL UNITS — When the fan switch is set for automatic
(AUTO) operation, the indoor-fan contactor (IFC) is cycled
with the lead compressor. If the fan switch is set for con-
tinuous (CONT), the IFC is energized as long as the unit
power is on.
Restart After Stoppage by Safety Control — The
high-pressure switch, compressor discharge gas thermostats,
and the oil pressure switch must be reset manually by break-
ing the control power supply at any of the following points:
control circuit fuse, fan motor circuit breaker, or the ther-
mostat. Restart follows the Time Guard control delay.
Stoppage by low-pressure switch results in Time Guard
control delay, then unit attempts normal restart.
The compressor motor overcurrent protectors are manual-
reset circuit breakers. Reset of control circuit may also be
necessary.
Condenser Fans — Each fan is supported by a formed
wire mount bolted to fan deck and covered with a wire guard.
The exposed end of fan motor shaft is protected from weather
by grease. If fan motor must be removed for service or re-
placement, be sure to regrease fan shaft, and reinstall fan
7
guard. For proper performance, fan should be
⁄8
in.
(22 mm) below top of venturi on the fan deck to top of
the fan hub for 60-Hz units, and ⁄2 in. (13 mm) for 50-Hz
1
Independent Refrigerant Circuit Controls — Each
refrigeration circuit is controlled by independent circuitry.
Therefore, it is possible to maintain partial cooling capabil-
ity even if one compressor is inoperable.
units. (See Fig. 49.) Tighten set screws to 15 ± 1 ft-lbs
(20 ± 1.3 N-m). Figure 49 shows proper position of mounted
fan.
IMPORTANT: Check for proper fan rotation (clock-
wise viewed from above). If necessary to reverse, switch
leads.
NOTE: The 38AH044-084 optional single-circuit units do
not have independent control circuitry.
50
TRANSFORMERS
FAN CONTACTORS
TIMERS
TIME-DELAY
RELAY
COMPRESSOR
CIRCUIT
BREAKERS
FAN CIRCUIT
BREAKER
TERMINAL
BLOCKS
OIL PRESSURE
SWITCHES
FUSE
HOLDERS
TERMINAL
BLOCKS
COMPRESSOR
CONTACTORS
Fig. 48 — Unit Control Box
Required Compressor Modification for 38AH044-
084 Optional Single-Circuit Units, When Com-
pressor A1 is Out — To maintain unit operation, com-
pressor no.1 must be operable. If it is not operable, the following
temporary modifications must be made to keep the unit
running:
1. Change the oil pressure switch connections from com-
pressor A1 to compressor A2.
2. Connect compressor A2 into the Time Guard circuit as
compressor A1 was originally.
3. Open compressor A1 circuit breaker.
NOTE: Make sure the crankcase heaters are energized when
compressors are off.
NOTE: Fan rotation is clockwise when viewed from top of unit.
Fig. 49 — Condenser Fan Adjustment
51
Compressor Removal — Access to the pump end
of the compressor is from the compressor side of the unit.
Access to the motor end of the compressor is from the inside
of the unit. All compressors can be removed from the com-
pressor side of the unit.
Compressor Replacement — Perform the following:
1. Reverse procedure in Compressor Removal section to end
of Step 4.
2. Reinstall service valves and safety switches, and tighten
to torques as listed:
IMPORTANT: All compressor mounting hardware and
support brackets removed during servicing must be re-
installed prior to start-up.
Torque
Compressor(s)
Tighten discharge valves to —
20-25 ft-lbs ( 27- 34 N-m)
80-90 ft-lbs (109-122 N-m)
Tighten suction valves to —
80- 90 ft-lbs (109-122 N-m)
90-120 ft-lbs (122-163 N-m)
06E-250
06E-265,275,299
1. Disconnect power to unit; lockout power to compressor.
2. Close suction and discharge service valves.
3. Relieve refrigerant pressure into a refrigerant recovery
system.
06E-250
06E-265,275,299
Tighten the following fittings as specified —
60 ft-lbs (81 N-m)
120 in.-lbs (13.5 N-m)
4. Remove:
Discharge Gas Thermostat
High-Pressure Switch, Fan-
Cycling Pressure Switch
a. Fan-cycling pressure switch (FCPS)
b. High-pressure switch
c. Low-pressure switch
120 in.-lbs (13.5 N-m)
Low-Pressure Switch
d. Oil-pressure switch
e. Discharge gas temperature switch.
5. Disconnect power wires at terminal box and disconnect
conduit.
6. Disconnect wires from crankcase heater.
7. Disconnect service valves from compressor.
3. Leak-check and evacuate system, reclaim refrigerant.
4. Recharge system per pre-start-up and start-up sequences.
Recheck oil levels.
5. Energize crankcase heater for 24 hours prior to restart of
system.
OIL CHARGE — (Refer to Table 3A, 3B, 4A, or 4B.) All
units are factory charged with oil. Acceptable oil level for
each compressor is from 1⁄8 to 1⁄3 of sight glass (see Fig. 29,
page 38).
When additional oil or a complete charge is required, use
only Carrier-approved compressor oil.
NOTE: On 38AH044-084 optional single-circuit units and
units with 2 compressors per circuit, disconnect both oil
equalizer lines located on the motor barrel and on the oil
pump sump.
8. Units 38AH044-084, 124, and 134:
a. Remove 4 large screws securing compressor mount-
ing pan to unit base rail.
b. Slide compressor (on mounting pan) to outside of unit
frame; support and/or lower to ground.
Approved oils are:
Petroleum Specialties, Inc. — Cryol 150A (factory oil charge)
Texaco, Inc.
Witco Chemical Co.
— Capella WF-32-150
— Suniso 3GS
c. Unbolt compressor from mounting pan and remove.
9. Units 38AH094, 104:
OIL REQUIRED
Pts
COMPRESSOR
L
a. Remove 4 large screws securing compressor to the com-
pressor rails.
b. Lift compressor off mounting bolts and remove.
06E-250
06E-265
06E-275
06E-299
17
21
21
19
8.0
9.9
9.9
9.0
Do not reuse drained oil, and do not use any oil that has
been exposed to atmosphere.
Adjust oil level in accordance with Start-Up, Preliminary
Oil Charge, page 38.
52
TROUBLESHOOTING
PROBLEM
COMPRESSOR DOES NOT RUN
Contactor Open
SOLUTION
1. Power off.
1. Restore power.
2. Fuses blown in field power circuit.
2. After finding cause and correcting, replace with correct
size fuse.
3. No control power.
3. Check secondary fuse(s); replace with correct type and
size. Replace transformer if primary windings receiving
power.
4. Thermostat circuit open.
4. Check thermostat setting.
5. Multi-function timer not operating.
6. Compressor circuit breaker tripped.
5. Check timer for proper operation; replace if defective.
6. Check for excessive compressor current draw. Reset
breaker; replace if defective.
7. Safety device lockout circuit active.
8. Low-pressure switch open.
7. Reset lockout circuit at thermostat or circuit breaker.
8. Check for refrigerant undercharge, obstruction of indoor
airflow, or whether compressor suction shutoff valve is
fully open. Make sure liquid line solenoid valve(s) is
open.
9. High-pressure switch open.
9. Check for refrigerant overcharge, obstruction of outdoor
airflow, air in system or whether compressor discharge
valve is fully open. Be sure outdoor fans are operating
correctly.
10. Discharge gas temperature switch open.
10. Check for open condition. Allow for reset. Replace if
defective.
11. Loose electrical connections.
12. Compressor stuck.
11. Tighten all connections.
12. See 06E compressor service literature.
Contactor Closed
1. Compressor leads loose.
2. Motor windings open.
3. Single phasing.
1. Check connections.
2. See 06E compressor service literature.
3. Check for blown fuse. Check for loose connection at
compressor terminal.
COMPRESSOR STOPS ON HIGH-PRESSURE SWITCH
Outdoor Fan On
1. High-pressure switch faulty.
2. Airflow restricted.
1. Replace switch.
2. Remove obstruction.
3. Air recirculating.
3. Clear airflow area.
4. Noncondensables in system.
5. Refrigerant overcharge.
6. Line voltage incorrect.
7. Refrigerant system restrictions.
4. Purge and recharge as required.
5. Purge as required.
6. Consult power company.
7. Check or replace filter drier, expansion valve, etc. Check
that compressor discharge valve is fully open.
Outdoor Fan Off
1. Fan slips on shaft.
2. Motor not running.
3. Motor bearings stuck.
4. Motor overload open.
5. Motor burned out.
1. Tighten fan hub setscrews.
2. Check power and capacitor.
3. Replace bearings.
4. Check overload rating. Check for fan blade obstruction.
5. Replace motor.
COMPRESSOR CYCLES ON LOW-PRESSURE SWITCH
Indoor-Air Fan Running
1. Filter drier plugged.
1. Replace filter drier.
2. Expansion valve power head defective.
3. Low refrigerant charge.
2. Replace power head.
3. Add charge. Check low-pressure switch setting.
Airflow Restricted
1. Coil iced up.
2. Coil dirty.
1. Check refrigerant charge.
2. Clean coil fins.
3. Air filters dirty.
4. Dampers closed.
3. Clean or replace filters.
4. Check damper operation and position.
Indoor-Air Fan Stopped
1. Electrical connections loose.
2. Fan relay defective.
1. Tighten all connections.
2. Replace relay.
3. Motor overload open.
4. Motor defective.
3. Power supply.
4. Replace motor.
5. Fan belt broken or slipping.
5. Replace or tighten belt.
53
TROUBLESHOOTING (cont)
PROBLEM
SOLUTION
COMPRESSOR STOPS ON OIL PRESSURE SWITCH
1. Oil level too low or too high.
1. Check oil level requirements; adjust oil level until sight
1
1
glass is filled
2. Check for
⁄
8
to
⁄
3
when running.
2. Compressor is short cycling.
a) Thermostat location and operation.
b) Safety device lockout circuit operation.
c) End-of-cycle control and timer operation.
d) Low-pressure switch and relay operation.
3. Check relay operation; replace crankcase heater(s), if
defective.
3. Crankcase heater off.
4. Low refrigerant charge.
4. Adjust charge as required.
5. Refrigerant floodback.
5. Adjust TXV superheat.
6. Evaporator coil is blocked or iced.
7. Evaporator fan not operating.
8. Distributor and/or TXV too large.
6. Check and correct as required.
7. Check and correct as required.
8. Check sizing at design conditions; change if incorrect
for current application.
9. Suction riser too large.
9. Check line sizing at minimum design condition; change
piping if incorrect.
10. Defective oil pressure switch.
10. Check switch for proper operation; check capillary lines
for plugged lines.
11. Plugged oil pump inlet screen.
12. Faulty oil pump drive segment.
13. Worn oil pump.
11. Clean oil pump screen.
12. Replace drive segment.
13. Replace bearing head assembly.
14. Replace compressor; see 06E service instructions.
14. Worn compressor bearings.
COMPRESSOR RUNNING BUT COOLING INSUFFICIENT
Suction Pressure Low
1. Refrigerant charge low.
2. Head pressure low.
1. Add refrigerant.
2. Check refrigerant charge.
Check outdoor-air fan thermostat settings.
3. Clean or replace filters.
4. Replace power head.
5. Check low-pressure setting.
6. Remove obstruction.
3. Air filters dirty.
4. Expansion valve power head defective.
5. Indoor coil partially iced.
6. Indoor airflow restricted.
Suction Pressure High
1. Unloaders not functioning.
1. Check unloader adjustments.
Check unloader setting.
2. Compressor valve defective.
3. Heat load excessive.
2. See 06E compressor service literature.
3. Check for open doors or windows in vicinity of fan coil.
UNIT OPERATES TOO LONG OR CONTINUOUSLY
1. Low refrigerant charge.
1. Add refrigerant.
2. Control contacts fused.
2. Replace control.
3. Air in system.
4. Partially plugged expansion valve or filter drier.
3. Purge and evacuate system.
4. Clean or replace.
SYSTEM IS NOISY
1. Piping vibration.
1. Support piping as required.
2. Compressor noisy.
2. Check valve plates for valve noise. Replace compressor
if bearings are worn.
COMPRESSOR LOSES OIL
1. Leak in system.
1. Repair leak.
2. Crankcase heaters not energized during shutdown.
2. Check wiring and relays. Check heater and replace if
defective.
3. Improper interconnecting piping design.
FROSTED SUCTION LINE
3. Check piping for oil return. Replace if necessary.
1. Expansion valve admitting excess refrigerant.
HOT LIQUID LINE
1. Adjust expansion valve.
1. Shortage of refrigerant due to leak.
2. Expansion valve opens too wide.
1. Repair leak and recharge.
2. Adjust expansion valve.
FROSTED LIQUID LINE
1. Restricted filter drier.
1. Remove restriction or replace.
COMPRESSOR WILL NOT UNLOAD
1. Defective unloader.
1. Replace unloader.
2. Replace valve.
3. Rewire correctly.
4. Replace spring.
2. Defective capacity control solenoid valve (if used).
3. Miswired capacity control liquid line solenoid (if used).
4. Weak, broken, or wrong valve body spring.
COMPRESSOR WILL NOT LOAD
1. Miswired capacity control liquid line solenoid (if used).
2. Defective capacity control solenoid valve (if used).
3. Plugged strainer (high side).
1. Rewire correctly.
2. Replace valve.
3. Clean or replace strainer.
4. Clean or replace the necessary parts.
4. Stuck or damaged unloader piston or piston ring(s).
Copyright 1998 Carrier Corporation
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1
PC 111
Catalog No. 563-704
Printed in U.S.A.
Form 38AH-15SI
54
10-98
Replaces: 38AH-14SI
Tab 3a
START-UP CHECKLIST
A. Preliminary Information
OUTDOOR: MODEL NO.
SERIAL NO.
SERIAL NO.
INDOOR: AIR HANDLER MANUFACTURER
MODEL NO.
ADDITIONAL ACCESSORIES
B. Pre-Start-Up
OUTDOOR UNIT
IS THERE ANY SHIPPING DAMAGE?
IF SO, WHERE:
(Y/N)
WILL THIS DAMAGE PREVENT UNIT START-UP?
CHECK POWER SUPPLY. DOES IT AGREE WITH UNIT?
HAS THE GROUND WIRE BEEN CONNECTED? (Y/N)
(Y/N)
(Y/N)
HAS THE CIRCUIT PROTECTION BEEN SIZED AND INSTALLED PROPERLY?
ARE THE POWER WIRES TO THE UNIT SIZED AND INSTALLED PROPERLY?
(Y/N)
(Y/N)
HAVE COMPRESSOR HOLDDOWN BOLTS BEEN LOOSENED?
(Y/N)
CONTROLS
ARE THERMOSTAT(S) AND INDOOR FAN CONTROL WIRING
CONNECTIONS MADE AND CHECKED?
(Y/N)
ARE ALL WIRING TERMINALS (including main power supply) TIGHT?
HAVE CRANKCASE HEATERS BEEN ENERGIZED FOR 24 HOURS?
(Y/N)
(Y/N)
INDOOR UNIT
HAS WATER BEEN PLACED IN DRAIN PAN TO CONFIRM PROPER DRAINAGE?
ARE PROPER AIR FILTERS IN PLACE? (Y/N)
HAVE FAN AND MOTOR PULLEYS BEEN CHECKED FOR PROPER ALIGNMENT?
(Y/N)
(Y/N)
DO THE FAN BELTS HAVE PROPER TENSION?
(Y/N)
PIPING
ARE LIQUID LINE SOLENOID VALVES LOCATED AT THE EVAPORATOR COILS AS REQUIRED?
(Y/N)
HAVE LEAK CHECKS BEEN MADE AT COMPRESSORS, CONDENSERS, EVAPORATORS,
TXVs (Thermostatic Expansion Valves) SOLENOID VALVES, FILTER DRIERS, AND FUSIBLE PLUGS
WITH A LEAK DETECTOR?
(Y/N)
LOCATE, REPAIR, AND REPORT ANY LEAKS.
HAVE ALL COMPRESSOR SERVICE VALVES BEEN FULLY OPENED (BACKSEATED)?
(Y/N)
1
ARE THE COMPRESSOR OIL SIGHT GLASSES SHOWING ABOUT ⁄2 FULL?
(Y/N)
CHECK VOLTAGE IMBALANCE
LINE-TO-LINE VOLTS:
(AB + AC + BC)/3 = AVERAGE VOLTAGE =
MAXIMUM DEVIATION FROM AVERAGE VOLTAGE =
AB
V
AC
V
BC
V
V
V
VOLTAGE IMBALANCE = 100 X (MAX DEVIATION)/(AVERAGE VOLTAGE) =
%
IF OVER 2% VOLTAGE IMBALANCE, DO NOT ATTEMPT TO START SYSTEM!
CALL LOCAL POWER COMPANY FOR ASSISTANCE.
CL-1
C. Start-Up
CHECK EVAPORATOR FAN SPEED AND RECORD.
CHECK CONDENSER FAN SPEED AND RECORD.
AFTER AT LEAST 10 MINUTES RUNNING TIME, RECORD THE FOLLOWING MEASUREMENTS:
COMP A1
COMP A2
COMP B1
COMP B2
OIL PRESSURE
SUCTION PRESSURE
SUCTION LINE TEMP
DISCHARGE PRESSURE
DISCHARGE LINE TEMP
ENTERING CONDENSER AIR TEMP
LEAVING CONDENSER AIR TEMP
EVAP ENTERING AIR DB TEMP
EVAP ENTERING AIR WB TEMP
EVAP LEAVING AIR DB TEMP
EVAP LEAVING AIR WB TEMP
COMPRESSOR AMPS (L1)
COMPRESSOR AMPS (L2)
COMPRESSOR AMPS (L3)
CHECK THE COMPRESSOR OIL LEVEL SIGHT GLASSES; ARE THE SIGHT GLASSES SHOWING
1
1
OIL LEVEL AT
⁄8
TO
⁄
3
FULL?
(Y/N)
NOTES:
Copyright 1998 Carrier Corporation
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1
PC 111
Catalog No. 563-704
Printed in U.S.A.
Form 38AH-15SI
CL-2
10-98
Replaces: 38AH-14SI
Tab 3a
|