UNIT 38AH 0-034 Wiring Diagrams Units Produced After April 20, 2009 (Includes Variable Air Volume ModuPanel Control) ELECTRICAL CHARACTERISTICS (V-Ph-Hz) 208/-3-60, 460-3-60 575-3-60 380-3-60-3-50, 380/415-3-50 346-3-50 INDEX Fig. Unit 38AH with Two-Stage Thermostat........................................ 9 One 38AH Dual-Circuit Condensing Unit with ModuPanel Control................. 10 Two 38AH Dual-Circuit Condensing Units with ModuPanel Control................. 11 38AH0-034 Air-Cooled Condensing Units 50/60 Hz DIAGRAM TYPE FIGURE NO. LABEL DIAGRAM NO. Component Arrangement 1 38AH500185-4 Power Schematic 2 38AH500184-5 Component Arrangement 3 38AH500181-4 Power Schematic 4 38AH500180-5 Component Arrangement 5 38AH500183-4 Power Schematic 6 38AH500182-5 Component Arrangement 7 38AH500187-4 Power Schematic 8 38AH500186-5 AFR Airflow Relay AFS Airflow Switch ATS Air Temperature Switch C Contactor, Compressor CB Circuit Breaker CH Crankcase Heater CM Control Module COMP Compressor COTP Compressor Overtemperature Protection CR Control Relay DU Dummy EQUIP Equipment FC Fan Contactor FIOP Factory-Installed Option FM Fan Motor FR Fan Relay FU Fuse GND Ground HPS High-Pressure Switch IFC LLSV LPS MMF MMPT MPR NEC OPS PL PRI RLA SEC TB TRAN U VAV LEGEND (For Fig. 1-11) Indoor (Evaporator) Fan Contactor Liquid Line Solenoid Valve Low-Pressure Switch Motormaster Fuse Motormaster Pressure Transducer ModuPanel Relay National Electrical Code (U.S.A. Standard) Oil Pressure Switch Primary Primary Rated Load Amps Secondary Terminal Block Transformer Unloader Variable Air Volume Plug Receptacle Terminal Block Connection Unmarked Terminal Marked Splice Unmarked Splice Factory Wiring Field Control Wiring Field Power Wiring Indicates common potential. (Does not represent wiring.) Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations. Catalog No. 04-56380002-01 Printed in U.S.A. Form 38AH-9W Pg 1 709 4-09 Replaces: 38AH-8W
1. For TRAN2: for 208/ v connect to H3; for 460 v, connect to H4. 2. TRAN 1: for 208/ v, connect to orange lead; for 460 v, connect to black lead. 3. Compressor and fan motors are thermally protected. Threephase motors are protected against primary single-phasing conditions. 4. Replacement of original wires must be with type 90 C wire or its equivalent. 5. Factory wiring is in accordance with NEC. Field modifications or additions must be in compliance with all applicable codes. 6. Wiring for field power supply must be rated 75 C. Use copper, copper-clad aluminum, or aluminum conductors. 7. FU1 is used on 208/-3-60 units only. 8. Thermostat wire between RC and TB2-1 is not connected when AFS is used. 9. Control circuit power (va) available at TB2 is as follows: VA ITEM 40 Standard unit, no winter start 34 Standard unit with winter start on circuits no. 1 and 2 16 VAV VIOP, no winter start 9 VAV FIOP with winter start on circuits no. 1 and 2 NOTES (For Fig. 1-8) 10. Reset OPS before resetting thermostat. 11. The AFR is used only when 38AH is connected to a single air handler. Use airflow relay Carrier part no. HN61KK040, HN61KK060, or equivalent. 12. The following table lists information for replacement of CB3, CB4, and CB5. CB3 CB4 AND 5 Max Voltage Rating Mfg Part No. Potter & Brumfield Must- Trip Amps Max Voltage Rating Mfg Part No. Potter & Brumfield Must- Trip Amps 250-v W28X-1029-5 5.0 250-v W2BX-10-3.2 3.2 2
NOTES (cont) 13. The motor-compressor is a thermally protected system. Circuit breaker must-trip amps are less than or equal to 156% RLA. 60 Hz UNITS The following tables list compressor and fan circuit breaker data. UNIT SIZE 38AH MAIN VOLTAGE 0500 208/ 028500 208/ 034500 208/ 0600 460 028600 460 034600 460 0100 575 028100 575 034100 575 0200 380 028200 380 034200 380 UNIT SIZE 38AH MAIN VOLTAGE 0800 028800 034800 0900 380/415 028900 380/415 034900 380/415 0300 346 028300 346 034300 346 CONTROL VOLTAGE CONTROL VOLTAGE Heinemann 50 Hz UNITS COMP CB1 AND 2 Airpax MUST-TRIP AMPS 47-100-85 209-3-2599-372 55 47-100-76 209-3-2599-410 61 CB1 47-100-76 209-3-2599-410 61 CB2 47-100-82 209-3-2599-311 89 CF3-Z33-34 219-3-2600-438 27 CF3-Z33-62 219-3-2600-452 31 CF3-Z33-62 219-3-2600-452 31 CF3-Z33-59 219-3-2600-464 42 CB1 CF3-Z33-61 219-3-2600-451 25 CB2 CF3-Z33-61 219-3-2600-451 25 CB1 CF3-Z33-61 219-3-2600-451 25 CB2 CF3-Z33-61 219-3-2600-451 25 CB1 CF3-Z33-61 219-3-2600-451 25 CB2 CF3-Z229-16 219-3-2600-561 32 CF3-Z33-89 219-3-2600-459 33.6 CF3-Z228-38 219-3-2600-539 37 CF3-Z228-38 219-3-2600-539 37 CF3-Z228-39 219-3-2600-540 48 Heinemann COMP CB1 AND 2 Airpax MUST-TRIP AMPS 47-100-85 209-3-2599-372 55 47-100-76 209-3-2599-410 61 CB1 47-100-76 209-3-2599-410 61 CB2 47-100-82 209-3-2599-311 89 CF3-Z33-34 219-3-2600-438 27 CF3-Z33-62 219-3-2600-452 31 CB1 CF3-Z33-62 219-3-2600-452 31 CB2 CF3-Z33-59 219-3-2600-464 42 CF3-Z33-89 219-3-2600-459 33.6 CF3-Z33-38 219-3-2600-563 37 CB1 CF3-Z228-38 219-3-2600-539 37 CB2 CF3-Z228-39 219-3-2600-540 20 3
OPERATING SEQUENCE Standard Constant Volume Unit with 2-Stage Cooling Thermostat Seven seconds after a thermostat call for the first stage of cooling, compressor no. 1 and the outdoor fans start. The no. 2 fan only starts if the outdoor ambient temperature is above 70 F (21.1 C). The oil-pressure switch and the low-pressure switch are bypassed for 1 and 2 1 / 2 minutes, respectively. If either the low-pressure switch or oil pressure switch remain open after the delay, the unit shuts down and goes into alarm mode. The indoor-fan motor starts immediately whenever there is a call for cooling. If a liquid line solenoid valve has been installed (for refrigerant control during the off cycle), then the solenoid valve for compressor no. 1 opens immediately upon a call for cooling. On standard units, compressor no. 1 operates either fully loaded or at one step of unloading, depending on the suction pressure, which is dependent on the evaporator load conditions. As the cooling demand increases, the thermostat calls for the second stage of cooling. Within 7 seconds from a call for the second stage of cooling, compressor no. 2 starts. The oil switch and low-pressure switch for circuit no. 2 are bypassed during start-up. As the cooling load is satisfied, the thermostat stops the call for the second stage of cooling, which in turn deenergizes compressor no. 2, closes the no. 2 liquid line solenoid (if installed) and energizes the compressor no. 2 crankcase heater. If the space temperature continues to decrease, then the thermostat stops the call for the first stage of cooling, which then deenergizes compressor no. 1 and the outdoor fans, closes the no. 1 liquid line solenoid valve (if installed), and energizes the compressor no. 1 crankcase heater. The unit controls prevent both compressors from reenergizing within 3 minutes from a previous call for operation. If the unit safeties trip during operation, refer to the Installation Instructions shipped with the unit. To reset the lockout mode, cycle the unit power. NOTE: If the thermostat fan switch is in the auto position, the indoor fan cycles on and off as the thermostat calls for cooling (or heating). If the switch is in the continuous position, the fan runs when the outdoor unit is powered. Optional Variable Air Volume Unit with Modu- Panel Control The ModuPanel control regulates up to 10 stages of cooling to maintain a leaving-air temperature for variable air volume (VAV) applications. When connected to one 38AH condensing unit, only 6 stages are used. See Table 1 for unit loading and compressor operating sequence. When the timeclock connected to the panel closes, the indoor-fan contactor is energized through a field-supplied relay. (The relay must be a pilot-duty SPST relay with -v coil and 30 va maximum coil draw.) After the time delays programmed into the ModuPanel control have elapsed, and with the leaving air above the set point, the stages of mechanical cooling are sequenced as follows: 1. Stage 1 starts compressor no. 1 with 2 banks of cylinders unloaded ( 1 / 3 loaded). Both unloader solenoids are energized. 2. Stage 2 loads one bank of compressor no. 1 cylinders ( 2 / 3 loaded) by deenergizing unloader solenoid no. 1. 3. Stage 3 loads the second bank of compressor no. 1 by deenergizing unloader solenoid no. 2. 4. Stage 4 starts compressor no. 2 and unloads 2 banks of compressor no. 1 cylinders unloaded ( 1 / 3 loaded). Both unloader solenoids are energized. 5. Stage 5 loads one bank of compressor no. 1 cylinders ( 2 / 3 loaded) by deenergizing unloader solenoid no. 1. 6. Stage 6 loads one bank of compressor no. 1 cylinders (fully loaded) by deenergizing unloader solenoid no. 2. Two Optional Variable Air Volume Units with a Single ModuPanel Control The ModuPanel control regulates up to 10 stages of cooling to maintain a leavingair temperature for variable air volume (VAV) applications. When connected to two 38AH condensing units, all 10 stages are used. See Table 2 for unit loading and compressor operating sequence. When the timeclock connected to the panel closes, the indoor-fan contactor is energized through a field-supplied relay. (The relay must be a pilot-duty SPST relay with -v coil and 30 va maximum coil draw.) After the time delays programmed into the ModuPanel control have elapsed, and with the leaving air above the set point, the stages of mechanical cooling are sequenced as follows: 1. Stage 1 starts unit no. 1 compressor no. 1 with 2 banks of cylinders unloaded ( 1 / 3 loaded). Both unloader solenoids are energized. 2. Stage 2 loads one bank of unit no. 1 compressor no. 1 cylinders ( 2 / 3 loaded) by deenergizing unloader solenoid no. 1. 3. Stage 3 turns off unit no. 1 compressor no. 1 and starts compressor no. 2 fully loaded. 4. Stage 4 starts unit no. 1 compressor no. 1 with 2 banks of cylinders unloaded ( 1 / 3 loaded). Both unloader solenoids are energized. 5. Stage 5 loads one bank of unit no. 1 compressor no. 1 cylinders ( 2 / 3 loaded) by deenergizing unloader solenoid no. 1. 6. Stage 6 loads one bank of unit no. 1 compressor no. 1 cylinders (fully loaded) by deenergizing unloader solenoid no. 2. 7. Stage 7 starts unit no. 2 compressor no. 1 with 2 banks of cylinders unloaded ( 1 / 3 loaded). Both unloader solenoids are energized. 8. Stage 8 turns off unit no. 2 compressor no. 1 and starts compressor no. 2 fully loaded. 9. Stage 9 starts unit no. 2 compressor no. 1 with 2 banks of cylinders unloaded ( 1 / 3 loaded). Both unloader solenoids are energized. 10. Stage 10 loads 2 banks of unit no. 2 compressor no. 1 cylinders (fully loaded) by deenergizing both unloader solenoids. Restart Manual reset of the -v control circuit is required if unit is shut down by any of the safety devices. Applicable devices include the high-pressure switch (HPS), lowpressure switch (LPS), oil-pressure switch (OPS), and compressor overtemperature protection (COTP) switch. To restart the unit after the unit has been shut down, raise the thermostat set point above the space temperature (thereby removing the call for cooling) and then lower the set point back to the desired setting. If unit circuit breakers trip during unit shutdown, they must be reset manually. Causes of Complete Unit Shutdown: interruption of supplied power open compressor overtemperature protection (COTP) compressor electrical overload protection (CB1 or CB2) open high-pressure or low-pressure safety switches open oil pressure switch 4
Table 1 Unit Loading Sequence with ModuPanel Control STAGE NO. CYLINDERS LOADED CYLINDERS Compressor No. 1 Compressor No. 2 CAPACITY STEP (%) 1 2 2 17 2 4 4 33 3 6 6 50 4 8 2 6 67 5 10 4 6 83 6 12 6 6 100 Table 2 Loading Sequence, Two Condensing Units with ModuPanel Control UNIT 1 LOADED CYLINDERS UNIT 2 LOADED CYLINDERS STAGE NO. CYLINDERS Compressor No. 1 Compressor No. 2 Compressor No. 1 Compressor No. 2 CAPACITY STEP (%) 1 2 2 8 2 4 4 17 3 6 6 25 4 8 2 6 33 5 10 4 6 41 6 12 6 6 50 7 14 6 6 2 58 8 18 6 6 6 75 9 20 6 6 2 6 83 10 6 6 6 6 100 5
a38-7085.eps Fig. 1 Component Arrangement, 38AH0-034, 208/-3-60 and 460-3-60 Units 6
a38-7086 Fig. 2 Power Schematic, 38AH0-034, 208/-3-60 and 460-3-60 Units 7
a38-7087 Fig. 3 Component Arrangement, 38AH0-034, 575-3-60 Units 8
a38-7088 Fig. 4 Power Schematic, 38AH0-034, 575-3-60 Units 9
Fig. 5 Component Arrangement, 38AH0-034, 380-3-60 Units a38-7089 10
a38-7090 Fig. 6 Power Schematic, 38AH0-034, 380-3-60 Units 11
a38-7091 Fig. 7 Component Arrangement, 38AH0-034, -3-50, 380/415-3-50 and 346-3-50 Units 12
a38-7092 Fig. 8 Power Schematic, 38AH0-034, -3-50, 380/415-3-50 and 346-3-50 Units 13
*Use thermostat wiring shown here for single air-handler applications. CB3 protects control circuit at the following unit voltages: CONTROL CIRCUIT PROTECTED AT: (V-Ph-Hz) -1-60 UNIT (V-Ph-Hz) 208/-3-60 460-3-60 575-3-60-1-60 380-3-60-1-50-3-50 346-3-50 400-3-50 NOTES: 1. CB4 protects TB2 circuit; CB3 protects TB3 circuits. 2. LLSV1 and LLSV2 are field supplied. 3. On 208/, 460, and 575-3-60 units, TB2 is -v and TB3 is -v. On 380-3-60 and, 346, and 400-3-50 units, TB2 is -v and TB3 is -v. **For a single air handler, LLSV valve 1 is to be used on the lower (no. 1) evaporator circuit. The LLSV valve 2 is to be used on the upper (no. 2) evaporator circuit. Only one indoor-fan contactor is required on single air-handler applications. Use Carrier accessory part no. 40RR900181 for indoor-fan contactor. Fig. 9 Unit 38AH with Two-Stage Thermostat a38-7050.eps 14
C SEE MODUPANEL ACCESSORY INSTALLATION FOR SCHEMATIC NOTES: 1. Factory wiring is in accordance with National Electrical Code (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. Maximum incoming wire size for main terminal block (TB1) is 350 maximum kcmil ( v). All other voltages 2/0 maximum. 3. Terminal blocks TB2 and TB3 are for external field control connections. Control connections are to be Class 2 wiring. 4. Field supplied components (IFC, LLS-1 and LLS-2) must have a maximum sealed coil rating of 30 va (.25 amps at 120 vac,.13 amps at 120 vac). Thermostats must have a pilot duty rating of 120 va, (1 amp at 120 vac,.52 amp at vac). The fan switch must have a pilot duty rating of 30 va (.25 amp at 120 vac,.13 amp at vac). The AFS must have a pilot duty rating of 30 va (1.25 amps at vac). 5. Replacement of factory wires must be with type 105 C wire or its equivalent. 6. Field-supplied liquid line solenoid valves installed at the evaporator are required on Circuits 1 and 2 on all units. 7. TRAN1 has 75 va available for field-installed accessories. 8. ModuPanel control is wired for one air handler only. Fig. 10 One 38AH Dual-Circuit Condensing Unit with ModuPanel Control a38-7113 15 709
NOTES: 1. Factory wiring is in accordance with National Electrical Code (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. Maximum incoming wire size for main terminal block (TB1) is 350 kcmil ( v). All other voltages 2/0 maximum. 3. Terminal blocks TB2 and TB3 are for external field control connections. Control connections are to be Class 2 wiring. 4. Field supplied components connected to TB3 (e.g., LLSV1 and LLSV2) cannot exceed 75 va total inductive load at vac, so that TRAN1 does not become overloaded. The air handler auxiliary motor starter contacts must have a minimum contact rating of 30 va at vac. The airflow switch must have a minimum contact rating of 125 va at vac. 5. Replacement of factory wires must be with type 105 C wire or its equivalent. 6. Field supplied liquid line solenoid valves installed at the evaporator are required on Circuits 1 and 2 on all units. 7. TRAN1 has 75 va available for field-installed accessories. 8. ModuPanel is wired for one air handler only. 9. AFR only used with single air handler. Use HN61KK040,060 or equivalent. 10. For MPR, use HN61KK040,060 or equivalent. MPR MPR SEE MODUPANEL ACCESSORY INSTALLATION FOR SCHEMATIC SEE MODUPANEL ACCESSORY INSTALLATION FOR SCHEMATIC Fig. 11 Two 38AH Dual-Circuit Condensing Units with ModuPanel Control Copyright 2009 Carrier Corporation Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations. Catalog No. 04-56380002-01 Printed in U.S.A. Form 38AH-9W Pg 16 709 4-09 Replaces: 38AH-8W