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Power Supply —

Electrical characteristics of available

power supply must agree with unit nameplate rating. Supply
voltage must be within limits shown in Table 3.

IMPORTANT: Operating unit on improper supply volt-
age, or with excessive phase imbalance, constitutes abuse
and may affect Carrier warranty. See Unbalanced 3-Phase
Supply Voltage, page 7.

Power Wiring —

All power wiring must comply with

applicable local and national codes. Install field-supplied branch
circuit fused disconnect(s) per NEC (National Electrical Code,
U.S.A.) of a type that can be locked OFF or OPEN. Dis-
connect(s) must be within sight from and readily accessible
from unit in compliance with NEC Article 440-14.

GENERAL WIRING NOTES
1. A crankcase heater is wired in the control circuit so it is

always operable as long as power supply disconnect is
on, even if any safety device is open or unit stop-start
switch is off. It is protected by a 5-amp circuit breaker in
control power.

2. The power circuit field supply disconnect should never be

open except when unit is being serviced or is to be down
for a prolonged period. When operation is resumed, crank-
case heater should be energized for 24 hours before start-
up. If unit is to be shut down for a prolonged period, it
is recommended that the suction and discharge valves be

closed to prevent an excessive accumulation of refriger-
ant in the compressor oil.

3. Power entry is one end only.
4. Maximum field wire sizes allowed by lugs on terminal

block are:

UNIT

38AKS

V-Ph-Hz

WIRE
SIZE*

028

208/230-3-60

350 kcmil

034

208/230-3-60

230-3-50

044

208/230-3-60

230-3-50

LEGEND

AWG — American Wire Gage
kcmil — Thousand Circular Mils
*All other units use 2/0 AWG (67.4 mm

2

).

5. Terminals for field power supply are suitable for copper,

copper-clad aluminum, or aluminum conductors. Insula-
tion must be rated 167 F (75 C) minimum.

CONDENSER FANS — The fans must rotate counterclock-
wise when viewed from above. If necessary, correct direc-
tion of fan rotation by interchanging any 2 power input wires
at disconnect switch. Affix crankcase heater decal (located
in installer’s packet) to unit disconnect switch.

Table 3 — Electrical Data

60 HZ

UNIT

38AKS

UNIT

COMPRESSOR

FAN MOTORS

Volts

3 Ph, 60 Hz

Supplied*

MCA

MOCP
(Fuse)

ICF

RLA

LRA

FLA (ea)

Qty

Min.

Max.

028

500
200
600
100

208/230

380
460
575

187
342
414
518

254
418
508
632

124.6

64.7
60.7
52.5

200

110

100

80

452.2
250.9
226.1
167.4

89.8
45.5
43.6
36.5

446
247
223
164

6.2
3.9
3.1
3.4

2
2
2
2

034

500
200
600
100

208/230

380
460
575

187
342
414
518

254
418
508
632

145.5

72.5
68.7
54.9

250
125

110

90

512.2
283.9
256.1
179.4

106.5

52.6
50.0
38.5

506
280
253
176

6.2
3.9
3.1
3.4

2
2
2
2

044

500
200
600
100

230
380
460
575

187
342
414
518

254
418
508
632

203.0

111.1

91.0
81.5

350
175
150
125

702.4
389.8
351.2
282.8

147.5

79.5
65.4
57.1

690
382
345
276

6.2
3.9
3.1
3.4

3
3
3
3

50 HZ

UNIT

38AKS

UNIT

COMPRESSOR

FAN MOTORS

Volts

3 Ph, 50 Hz

Supplied*

MCA

MOCP
(Fuse)

ICF

RLA

LRA

FLA (ea)

Qty

Min.

Max.

028

800
300
900

230
346
400

198

311

342

254
380
400

109.0

64.9
60.5

175
100
100

348.4
263.4
226.0

76.9
44.9
43.6

342
259
223

6.4
4.4
3.0

2
2
2

034

800
300
900

230
346
400

198

311

342

254
380
400

120.2

76.1
68.5

200
125

110

372.4
298.4
256.0

85.9
53.9
50.0

366
294
253

6.4
4.4
3.0

2
2
2

044

800
300
900

230
346
400

198

311

342

254
380
400

150.6

112.6

90.8

250
175
150

557.8
408.8
351.0

105.1

79.5
65.4

545
400
345

6.4
4.4
3.0

3
3
3

LEGEND

CSA

— Canadian Standards Association

FLA

— Full Load Amps

ICF

— Maximum Instantaneous Current Flow during starting (the point

in the starting sequence where the sum of the LRA for the start-
ing compressor, plus the total FLA for all running fan motors is
maximum).

LRA

— Locked Rotor Amps

MCA

— Minimum Circuit Amps (complies with National

Electrical Code [NEC, U.S.A.], Section 430-24)

MOCP — Maximum Overcurrent Protection
RLA

— Rated Load Amps

UL

— Underwriters’ Laboratories

*Units are suitable for use on electrical systems where voltage sup-

plied to unit terminals is not below or above listed minimum and maxi-
mum limits.

6

Summary of Contents for 38AKS028

Page 1: ...ntenance 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 Follow all safety codes Wear safety glasses and work gloves Keep quenching cloth and fire extinguisher nearby when brazing Use care in handling rigging and setti...

Page 2: ...ice Oil Charge for Carrier approved oil NOTE Circuit breaker is in main power circuit Table 1B Physical Data SI UNIT 38AKS 028 034 044 COMPRESSOR Reciprocating Semi Hermetic No Type 1 06E9265 1 06E9275 1 06E9299 No Cyls ea Speed R s 60 50 Hz 6 29 2 24 3 Capacity Steps 3 Oil Charge L 9 4 9 4 9 0 Oil Pressure Switch kPa Set Points Cutout 41 4 6 13 8 Differential Cut in 96 5 Max Crankcase Heater watt...

Page 3: ... side condenser and liquid line of the system during the off cycle Refrigerant migration is minimized Factory supplied liquid line solenoid valve connecting sizes are 7 8 in 22 2 mm ODF for inlet and 7 8 in 22 2 mm ODM for outlet Failure to properly install liquid line solenoid at the in door unit as described without Carrier authorization may VOID warranty Filter Drier and Moisture Indicator Ever...

Page 4: ... Manual at design tons and equiva lent length for 2 F 1 1 C loss If reading falls be tween 2 sizes on chart choose the smaller pipe size Suction piping for the high velocity section should be selected for about 0 5 F 0 3 C friction loss If a 2 F 1 1 C loss is allowed for the entire suction line 1 5 F 0 8 C is left for the balance of the suction line and it should be sized on that basis Check that ...

Page 5: ...T 38AKS LENGTH OF INTERCONNECTING PIPING FT M 16 25 4 9 7 6 26 50 7 9 15 2 51 75 15 5 22 8 76 100 23 2 30 5 101 200 30 8 60 9 L S L S L S L S L S 028 7 8 15 8 7 8 21 8 7 8 21 8 7 8 21 8 7 8 21 8 034 7 8 21 8 7 8 21 8 7 8 21 8 11 8 25 8 11 8 25 8 044 7 8 21 8 7 8 21 8 11 8 25 8 11 8 25 8 11 8 25 8 L Liquid Line S Suction Line IMPORTANT Requires a double suction riser if evaporator is below condensi...

Page 6: ... from above If necessary correct direc tion of fan rotation by interchanging any 2 power input wires at disconnect switch Affix crankcase heater decal located in installer s packet to unit disconnect switch Table 3 Electrical Data 60 HZ UNIT 38AKS UNIT COMPRESSOR FAN MOTORS Volts 3 Ph 60 Hz Supplied MCA MOCP Fuse ICF RLA LRA FLA ea Qty Min Max 028 500 200 600 100 208 230 380 460 575 187 342 414 51...

Page 7: ...ge 1 cooling and terminal on TB3 See Fig 8 for typical field wiring This is in the 24 v cir cuit Wires must be run in conduit with ground wire 4 Transformer Connections See unit wiring label dia gram notes 1 and 2 located behind compressor compart ment end access door IMPORTANT Ensure power to the crankcase heater is always on except when servicing the unit If cir cuit breaker inside unit shuts do...

Page 8: ...NOTES 1 There must be minimum 2440 mm 8 ft clear air space above unit 2 The approximate operating weight of the unit is 50 AND 60 HZ UNIT WT Lb WT Kg 38AKS028 1650 748 38AKS028C 1804 818 38AKS034 1803 818 38AKS034C 2009 911 3 A C in the model number indicates unit has factory installed copper coil 8 ...

Page 9: ...0 mm 8 ft clear air space above unit 2 The approximate operating weight of the unit is 50 HZ AND 60 HZ UNIT WT Lb WT Kg 38AKS044 2437 1106 38AKS044C 2745 1246 Fig 7 Dimensional Drawing 38AKS044 3 A C in the model number indicates unit has factory installed copper coil 9 ...

Page 10: ...compliance with all applicable codes 2 All field interlock contacts must have minimum rat ing of 180 va pilot duty plus capacity required for field installed equipment All field interlock con tacts in the 24 v control circuit must have minimum rating of 70 va pilot duty plus capacity required for field installed equipment 3 For internal unit wiring reference wiring book or unit wiring label diagra...

Page 11: ...reaker CR Control Relay CM Control Module EQUIP Equipment FC Fan Contactor Fig 9A Component Arrangement 60 Hz FM Fan Motor FU Fuse GND Ground LLSV Liquid Line Solenoid Valve NEC National Electrical Code U S A TB Terminal Block TRAN Transformer LEGEND 11 ...

Page 12: ...ker CR Control Relay CM Control Module EQUIP Equipment FC Fan Contactor FM Fan Motor FU Fuse GND Ground LLSV Liquid Line Solenoid Valve NEC National Electrical Code U S A TB Terminal Block TDR Time Delay Relay TRAN Transformer Fig 9B Component Arrangement 50 Hz 12 ...

Page 13: ... short cycle feature of the control module CM Charge System Actual start up should be done only under supervision of a qualified refrigeration mechanic Re fer to charging charts See Fig 10 12 for the particular unit being charged Mea sure pressure at the liquid line service valve being sure a Schrader depressor is used if required Also measure liquid line temperature as close to the liquid service...

Page 14: ...Fig 10 38AKS028 Charging Chart 50 60 Hz 14 ...

Page 15: ...Fig 11 38AKS034 Charging Chart 50 60 Hz 15 ...

Page 16: ...Fig 12 38AKS044 Charging Chart 50 60 Hz 16 ...

Page 17: ...s the solenoid drop control valve The compressor stops and the crankcase heater is energized preventing refrigerant from migrating to the com pressor during the off cycle solenoid drop refrigerant con trol The CM anti short cycling timer is energized and runs for approximately 5 minutes During this time the compres sor is not able to restart Complete Unit Stoppage CAUSES Interruption of supplied p...

Page 18: ...FC CM CR1 TRAN1 TB2 C1 COMPRESSOR END CONTROL PANEL REMOVED OIL PRESSURE SAFETY SWITCH COMPRESSOR END LEFT SIDE ACCESS DOOR JUNCTION BOX COVER REMOVED LIQUID LINE SERVICE VALVE COMPRESSOR END RIGHT SIDE ACCESS DOOR Fig 13 38AKS Unit with Access Panels Removed 18 ...

Page 19: ...aders are factory set see Table 1A or 1B but may be field adjusted Number 1 unloader is on cylinder bank on same side of compressor as terminal box CONTROL SET POINT The control set point cylinder load point is adjustable from 0 to 85 psig 0 to 586 kPag To adjust turn control set point adjustment nut Fig 15 clock wise to its bottom stop In this position set point is 85 psig 586 kPag Then turn adju...

Page 20: ...out Cut in 426 7 2937 48 320 20 2206 138 27 3 186 21 44 5 303 34 Winter Start Control Bypass relay timer bypasses low pressure switch for 2 minutes on unit start up Head Pressure Control Control maintains ad equate discharge pressure under low ambient temperature con ditions See Table 5 FAN CYCLING These 38AKS units have standard pro vision for fully automatic intermediate season head pressure con...

Page 21: ... is overcharged 4 Reclaim charge as needed UNIT OPERATES TOO LONG OR CONTINUOUSLY 1 Low refrigerant charge 1 Add refrigerant 2 Control contacts fused 2 Replace control 3 Air in system 3 Purge and evacuate system 4 Partially plugged expansion valve or filter drier 4 Clean or replace SYSTEM IS NOISY 1 Piping vibration 1 Support piping as required 2 Compressor noisy 2 Check valve plates for valve noi...

Page 22: ...e All programs include a video cassette and or slides and a companion booklet Use these for self teaching or to conduct full training sessions For a free Service Training Material Catalog STM call 1 800 962 9212 Ordering instructions are included Copyright 1994 Carrier Corporation Manufacturer reserves the right to discontinue or change at any time specifications or designs without notice and with...

Page 23: ... Y N INDOOR UNIT HAS WATER BEEN PLACED IN DRAIN PAN TO CONFIRM PROPER DRAINAGE Y N ARE PROPER AIR FILTERS IN PLACE Y N HAVE FAN AND MOTOR PULLEYS BEEN CHECKED FOR PROPER ALIGNMENT Y N DO THE FAN BELTS HAVE PROPER TENSION Y N PIPING ARE LIQUID LINE SOLENOID VALVE S LOCATED AT THE EVAPORATOR COIL AS REQUIRED Y N HAVE LEAK CHECKS BEEN MADE AT COMPRESSOR CONDENSER EVAPORATOR TXVs Thermostatic Expansio...

Page 24: ... 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 OIL LEVEL AT 1 8 TO 1 3 FULL Y N NOTES Copyright 1994 Carrier Corporation Manufacturer reserves the right to discontinue or change at any time specifications or designs without notice and wit...

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