Carrier 38MGR Series Service Manual

Carrier 38MGR Series Service Manual

Multi-zone outdoor unit ductless system, sizes 18, 24, 30, 36, 48
Table of Contents

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38MGR
Multi-zone Outdoor Unit Ductless System
Sizes 18, 24, 30, 36 and 48

TABLE of CONTENTS

SAFETY CONSIDERATIONS ....................................................... 1

INTRODUCTION............................................................................ 1

Specifications .......................................................................... 3
Dimensions ................................................................................. 4
Clearances................................................................................ 8
Electrical Data ..................................................................... 9
Wiring ........................................................................................... 9
Connection Diagrams ......................................................... 10
Automatic Wiring/Piping Correction ......................... 13
Wiring Diagrams..................................................................... 14
Refrigeration Cycle Diagrams...................................... 22
Refrigerant Lines .................................................................. 24
System Evacuation And Charging ............................... 25
Electronic Function............................................................ 26
Troubleshooting ................................................................... 31
Outdoor Unit Digital Display......................................... 32
OUTDOOR UNIT DISPLAY.......................................................... 32
Appendices.................................................................................. 64
Disassembly Instructions Size 18.................................. 72
Disassembly Instructions Size 24.................................. 80
Disassembly Instructions Size 30.................................. 89
SAFETY CONSIDERATIONS
Installing, starting up, and servicing air-conditioning equipment can
be hazardous due to system pressures, electrical components, and
equipment location (roofs, elevated structures, etc.).
Only trained, qualified installers and service mechanics should install,
start-up, and service this equipment.
Untrained personnel can perform basic maintenance functions such as
coil cleaning. 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 a
quenching cloth and fire extinguisher nearby when brazing. Use care
in handling, rigging, and setting bulky equipment.
Read this manual thoroughly and follow all warnings or cautions
included in the literature and attached to the unit. Consult local
building codes and National Electrical Code (NEC) for special
requirements. Recognize safety information.
This is the safety-alert symbol
unit and in instructions or manuals, be alert to the potential for
personal injury. Understand these signal words: DANGER,
WARNING, and CAUTION.
SERVICE MANUAL
PAGE
. When you see this symbol on the
These words are used with the safety-alert symbol. DANGER
identifies the most serious hazards which will result in severe personal
injury or death. WARNING signifies hazards which could result in
personal injury or death. CAUTION is used to identify unsafe
practices which may result in minor personal injury or product and
property damage. NOTE is used to highlight suggestions which will
result in enhanced installation, reliability, or operation.
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Before installing, modifying, or servicing system, main
electrical disconnect switch must be in the OFF position.
There may be more than 1 disconnect switch.
Lock out and tag switch with a suitable warning label.
WARNING
EXPLOSION HAZARD
Failure to follow this warning could result
in death, serious personal injury, and/or
property damage. Never use air or gases
containing oxygen for leak testing or
operating refrigerant compressors.
Pressurized mixtures of air or gases
containing oxygen can lead to an explosion.
CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
or improper operation.
Do not bury more than 36 in. (914 mm) of refrigerant pipe in
the ground. If any section of pipe is buried, there must be a 6
in. (152 mm) vertical rise to the valve connections on the
outdoor units. If more than the recommended length is buried,
refrigerant may migrate to the cooler buried section during
extended periods of system shutdown. This causes refrigerant
slugging and could possibly damage the compressor at start-up.
INTRODUCTION
This service manual provides the necessary information to service,
repair, and maintain the multi-zone family of heat pumps. This
manual has an appendix with data required to perform
troubleshooting. See "APPENDICES" on page 64. Use the "TABLE
of CONTENTS" on page 1 to locate a desired topic.

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Summary of Contents for Carrier 38MGR Series

  • Page 1 38MGR Multi-zone Outdoor Unit Ductless System Sizes 18, 24, 30, 36 and 48 SERVICE MANUAL TABLE of CONTENTS These words are used with the safety-alert symbol. DANGER identifies the most serious hazards which will result in severe personal injury or death. WARNING signifies hazards which could result in PAGE personal injury or death.
  • Page 2: Model / Serial Number Nomenclatures

    MODEL / SERIAL NUMBER NOMENCLATURES Table 1 — Unit Sizes SYSTEM TONS kBTUh VOLTAGE - PHASE OUTDOOR MODEL 208/230-1 38MGRQ18B--3 208/230-1 38MGRQ24C--3 208/230-1 38MGRQ30D--3 208/230-1 38MGRQ36D--3 208/230-1 38MGRQ48E--3 OUTDOOR UNIT 38 = OUTDOOR UNIT VOLTAGE 3 = 208/230-1-60 MG = ALL UNIT TYPE R = OUTDOOR UNIT NOT USED...
  • Page 3: Specifications

    SPECIFICATIONS Table 2 — Specifications SIZE System OUTDOOR MODEL 38MGRQ18B--3 38MGRQ24C--3 38MGRQ30D--3 38MGRQ36D--3 38MGRQ48E--3 Max Number of Zones Cooling Outdoor DB -13~122 -13~122 -13~122 -13~122 -13~122 °F (°C) Min - Max (-25~50) (-25~50) (-25~50) (-25~50) (-25~50) Operating Range Heating Outdoor DB -22~86 -22~86 -22~86...
  • Page 4: Dimensions

    DIMENSIONS Table 3 — Dimensions UNIT SIZE Height in (mm) 27.6 (703) 31.89 (810) 31.89 (810) 52.48 (1333) 52.48 (1333) Width in (mm) 37.31 (948) 41.22 (1047) 41.22 (1047) 41.14 (1045) 41.14 (1045) Depth in (mm) 14.82 (376) 17.91 (455) 17.91 (455) 17.63 (448) 17.63 (448)
  • Page 5 DIMENSIONS (CONT) Fig. 2 — Size 24K Fig. 3 — Size 30K 38MGR-04SM Specifications subject to change without notice.
  • Page 6 DIMENSIONS (CONTINUED) Fig. 4 — Size 36K Specifications subject to change without notice. 38MGR-04SM...
  • Page 7 DIMENSIONS (CONT) Fig. 5 — Size 48K 38MGR-04SM Specifications subject to change without notice.
  • Page 8: Clearances

    CLEARANCES Air-inlet Air-outlet Fig. 6 — Unit Clearances Table 4 — Unit Clearances MINIMUM VALUE UNIT in. (mm) 24 (609) 24 (609) 24 (609) 4 (101) 6 (152) NOTE: The outdoor unit must be mounted at least 2 in. (50mm) above the maximum anticipated snow depth. Fig.
  • Page 9: Electrical Data

    ELECTRICAL DATA Table 5 — Electrical Data SYSTEM VOLTAGE OPERATING VOLTAGE COMPRESSOR OUTDOOR FAN UNIT SIZE MOCP VOLT / PHASE / HZ MAX / MIN* 0.74 0.07 0.16 208-230/1/60 253 / 187 0.16 1.0x2 0.11 1.0x2 0.11 *Permissible limits of the voltage range at which the unit will operate satisfactorily. LEGEND •...
  • Page 10: Connection Diagrams

    CONNECTION DIAGRAMS Indoor Indoor Indoor Unit A Indoor Unit B Unit A Unit B Power Supply Power Supply Ground Signal Signal Ground High High 208-230-1-60 208-230-1-60 Voltage Voltage CONNECTING CABLE CONNECTING CABLE 208-230-1-60 FIELD POWER SUPPLY OUTDOOR TO INDOOR OUTDOOR TO INDOOR L1(B) L2(B) S(B) L1(A) S(A)
  • Page 11 CONNECTION DIAGRAMS (CONT) Fig. 10 — Size 30K 4 Zone Fig. 11 — Size 36K 4 Zone 38MGR-04SM Specifications subject to change without notice.
  • Page 12 CONNECTION DIAGRAMS (CONT) Indoor Indoor Indoor Indoor Indoor Indoor Unit A Indoor Unit C Indoor Unit D Indoor Unit E Indoor Unit B Unit A Unit C Unit D Unit E Unit B Power Supply Power Supply Power Supply Power Supply Power Supply Ground Ground...
  • Page 13: Automatic Wiring/Piping Correction

    AUTOMATIC WIRING/PIPING CORRECTION The unit is capable of automatically correcting a wiring/piping error. Indoor units do not have to be in the run mode. The outdoor temperature should be above 41F (5C) to use this feature. Press the CHECK button on the outdoor unit PCB board for 6 seconds until the display shows “CE”...
  • Page 14: Wiring Diagrams

    WIRING DIAGRAMS Size 18K RED(BROWN) INDOOR PIPE OUT TEMP BLUE CN12 CN15 CN14 CN29 CompTop LOW/HIGH L-OUT IPM BOARD MAIN BOARD ELECTRONIC VALVE-B EXPANSIVE VALVE ELECTRONIC VALVE-A EXPANSIVE VALVE BLUE BLUE CN14 BLACK BLUE L1-IN L2-IN 4-WAY HEAT1 HEAT2 CN1 CN2 DC FAN REACTOR L1(A)
  • Page 15 WIRING DIAGRAMS (CONT) Size 24K RED(BROWN) INDOOR PIPE OUT TEMP BLUE CN12 CN14 CN15 CN29 CompTop LOW/HIGH L-OUT ELECTRONIC EXPANSIVE VALVE-C VALVE IPM BOARD MAIN BOARD ELECTRONIC VALVE-B EXPANSIVE VALVE ELECTRONIC VALVE-A EXPANSIVE BLUE VALVE BLUE CN14 BLACK BLUE L1-IN L2-IN 4-WAY HEAT1...
  • Page 16 WIRING DIAGRAMS (CONT) Size 30K Applicable to the units BLACK adopting DC motor only COMP BLUE 5(6) CN33 CN41 CN20 CN43 4-WAY1 5(6) CN21 BLUE CN42 BLUE 5(6) CN22 CN17 BLUE BLUE 5(6) BLACK CN18 CN40 HEAT_Y CN10 5(6) CN19 CN44 BLACK HEAT_D...
  • Page 17 WIRING DIAGRAMS (CONT) Size 30K Table 11 — 30K - 4 Zone Max OUTDOOR UNIT PFC & IPM BOARD CODE PART NAME CN53~CN54 Input: 230VAC High voltage CN55 Output: Pin1 (12VDC),Pin2 (5VDC),Pin3 (EARTH) CN19 Pin1~Pin3: Connect to FAN voltage among phases 0~200VAC U~V~W Connect to compressor voltage among phases 0~200VAC CN51~CN52...
  • Page 18 WIRING DIAGRAMS (CONT) Size 36K Notes: This symbol indicates the element is optional,the actual shape shall be prevail. Ferrite bead Ferrite bead Ferrite bead MAIN BOARD CN13 BLUE BLACK Ferrite bead COMP CN16 FAN1 Ferrite bead CN21 CON1 DCFAN2 FAN1 DCFAN1 FAN2 CN29...
  • Page 19 WIRING DIAGRAMS (CONT) Size 36K Table 13 — 36K - 4 Zone Max OUTDOOR UNIT MAIN BOARD CODE PART NAME CN1~ CN3 Input: 230VAC High voltage CN13, CN16, CN21, CN29, CN37 Output: Pin1(Connection of the high voltage) “S” Pin2~ Pin3 (230VAC High voltage)“L1&L2” P5, P6, P9 Connection to the earth CN22...
  • Page 20 WIRING DIAGRAMS (CONT) Size 48K Notes: This symbol indicates the element is optional,the actual shape shall be prevail. Ferrite bead Ferrite bead Ferrite bead MAIN BOARD CN13 BLUE BLACK Ferrite bead COMP CN16 FAN1 Ferrite bead CN21 CON1 DCFAN2 FAN1 DCFAN1 FAN2 CN29...
  • Page 21 WIRING DIAGRAMS (CONT) Size 48K Table 17 — 48K - 5 Zone Max OUTDOOR UNIT MAIN BOARD CODE PART NAME CN1~CN3 Input: 230VAC High voltage CN13,CN16,CN21,CN29,CN37 Output: Pin1 (Connection of the high voltage) “S” Pin2~Pin3 (230VAC High voltage) “L1 & L2” P5,P6,P9 Connection to the earth CN22...
  • Page 22: Refrigeration Cycle Diagrams

    REFRIGERATION CYCLE DIAGRAMS EXV A CAPILIARY A LIQUID VALVE A CHECK VALVE EXV B CAPILIARY B LIQUID VALVE B Condenser temp. sensor CAPILIARY TUBE HEAT HEAT EXCHANGE T4 Ambient T1 Room EXCHANGE (EVAPORATOR) temp. sensor temp. sensor (CONDENSER) T2B-A Evaporator temp.
  • Page 23 REFRIGERATION CYCLE DIAGRAMS (CONT) EXV A CAPILIARY A LIQUID VALVE A EXV B CAPILIARY B LIQUID VALVE B CHECK VALVE EXV C CAPILIARY C LIQUID VALVE C Condenser temp. sensor EXV D CAPILIARY D CAPILIARY TUBE LIQUID VALVE D HEAT HEAT EXCHANGE T4 Ambient...
  • Page 24: Refrigerant Lines

    REFRIGERANT LINES General Refrigerant Line Sizing 1. The outdoor units are shipped with a full charge of R410A refrigerant. All charges, line sizing, and capacities are based on runs of 25 ft. (7.6 m) per number of zones. For runs over 25 ft. (7.6 m), consult the Long Line Application section on this page for proper charge adjustments. 2.
  • Page 25: System Evacuation And Charging

    SYSTEM EVACUATION AND CHARGING Deep Vacuum Method CAUTION The deep vacuum method requires a vacuum pump capable of pulling a vacuum of 500 microns and a vacuum gage capable of accurately measuring this vacuum depth. The deep vacuum method is the most positive way of assuring a system is free of air and liquid water (see UNIT DAMAGE HAZARD Fig.
  • Page 26: Electronic Function

    ELECTRONIC FUNCTION Compressor Current Limit Protection The temperature interval for the current limit is the same as the range Abbreviation of the T4 frequency limit. • T1: Indoor ambient temperature • T2: Middle indoor heat exchanger coil temperature • T2B: Indoor heat exchanger exhaust coil temperature (located on the outdoor unit) •...
  • Page 27: Controls And Functions

    High Condenser Coil Temperature Protection Table 25 — Cooling Mode CAPACITY AREA NORM CODE (N) Table 26 — Cooling Mode Decrease MODEL Hold Resume NOTE: The final result is an integer. Use Table 27 and the final capacity request to confirm the operating Fig.
  • Page 28 Heating Mode T1 Ts Fig. 33 — Heating Mode Table 28 — Heating Mode Capacity Area Norm code (N) Table 29 — Heating Mode Model NOTE: The final result is an integer. Fig. 35 — T2 Average Modify the result according to a T2 average (correction). Defrosting Control NOTE: Average value of T2;...
  • Page 29 End Defrosting Action If any one of following items is satisfied, defrosting stops and the machine enters the normal Heating mode. Increase fan speed 1. T3 > TempQuitDefrost_ADD °C 2. The defrosting time achieves 10 minutes 3. Turn to other modes or OFF Keep current fan speed Outdoor Fan Control Cooling Mode...
  • Page 30 Heating Mode Four-way valve control The initial open angle of EXV is 250P, dependent on indoor model In Heating mode, the four-way valve opens. In Defrosting mode, the four.way valve operates in accordance to the Defrosting action. In size, adjustment range is 100-400p. After the unit works for three other modes, the four-way valve is closed.
  • Page 31: Troubleshooting

    TROUBLESHOOTING This section provides the required flow charts to troubleshoot 5. Probe the outdoor board inputs and outputs with a digital multi- problems that may arise. meter referring to the wiring diagrams. NOTE: Information required in the diagnoses can be found 6.
  • Page 32: Outdoor Unit Display

    OUTDOOR UNIT DIGITAL DISPLAY A digital display is featured on the outdoor PCB. The LED displays different codes in the following situations: • Standby: “- -.” • Low ambient cooling mode: “LC” or alternative displays between running frequency and “LC” (each appears for 0.5s.) •...
  • Page 33 OUTDOOR UNIT DISPLAY (CONT) Table 32 — Outdoor PCB No. of Display Remark Presses Normal Display Displays running frequency, running state, or malfunction code Actual Data Display Number of Indoor Units Quantity of indoor units with working connection Outdoor unit running mode code Off: 0, Fan only: 1, Cooling: 2, Heating: 3, Forced cooling: 4.
  • Page 34: Diagnosis And Solution

    DIAGNOSIS AND SOLUTION Indoor fan speed has been out of control (E0/E4) ERROR CODE E0/F4 MALFUNCTION DECISION When the indoor fan speed remains low (300RPM) for certain period of time, the unit stops and the LED CONDITIONS displays the failure. •...
  • Page 35 DIAGNOSIS AND SOLUTION (CONT) Indoor units mode conflict (P5) Error Code P5 (old model) or - (new model) The indoor units cannot operate the Cooling mode and Heating mode at the same time. Malfunction decision conditions The Heating mode has the priority. •...
  • Page 36 DIAGNOSIS AND SOLUTION (CONT) EEPROM parameter error (EO/E4) ERROR CODE E0/F4 MALFUNCTION DECISION Indoor or outdoor PCB main chip does not receive feedback from EEPROM chip CONDITIONS • Installation mistake SUPPOSED CAUSES • PCB faulty Troubleshooting Shut off the power supply and turn it on 5 seconds later.
  • Page 37 DIAGNOSIS AND SOLUTION (CONT) Communication malfunction between the indoor and outdoor units (E2/E1) ERROR CODE E2/E1 MALFUNCTION DECISION Indoor unit does not receive feedback from the outdoor unit during 120 seconds or the outdoor unit CONDITIONS does not receive feedback from any indoor unit during 180 seconds. •...
  • Page 38 DIAGNOSIS AND SOLUTION (CONT) Fig. 43 —Test the DC voltage Use a multimeter to test the DC voltage between the L2 port and S port of the outdoor unit. The red pin of the multimeter connects with the L2 port while the black pin is for the S port. When AC is running normally, the voltage moves alternately between positive and negative values. Standby Fig.
  • Page 39 DIAGNOSIS AND SOLUTION (CONT) Pic 2: IPM (For four or five zone) Standby Power Fig. 45 — IPM for four or five zone Fig. 46 — Main Board The main board LED when power is on and the unit is in standby. Fig.
  • Page 40 DIAGNOSIS AND SOLUTION (CONT) Zero Crossing Detection Error Diagnosis and Solution (E2) ERROR CODE MALFUNCTION DECISION When PCB does not receive zero crossing signal feedback for four minutes or the zero crossing signal CONDITIONS interval is abnormal. • Connection mistake SUPPOSED CAUSES •...
  • Page 41 DIAGNOSIS AND SOLUTION (CONT) Communication malfunction between IPM board and outdoor main board) error diagnosis (E3) ERROR CODE MALFUNCTION DECISION PCB main chip does not receive feedback from IPM module during 60 seconds. CONDITIONS • Wiring mistake SUPPOSED CAUSES • PCB faulty Troubleshooting Communication malfunction between IPM board and outdoor main board.
  • Page 42 DIAGNOSIS AND SOLUTION (CONT) Fig. 49 —Test the voltage Fig. 48 — Test the voltage Remark: Use a multimeter to test the DC voltage between black pin and white pin of signal wire The normal value should be around 5V. Use a multimeter to test the DC voltage between black pin and red pin of signal wire.
  • Page 43 DIAGNOSIS AND SOLUTION (CONT) Open or short circuit of outdoor temperature sensor) diagnosis and solution F1/F2/F3/F4/F5 (open or short circuit of indoor coil temperature sensor) diagnosis and solution (E4) ERROR CODE E4/F1/F2/F3/F4/F5/F6 MALFUNCTION DECISION If the sampling voltage is lower than 0.06V or higher than 4.94V, the LED displays the failure. CONDITIONS •...
  • Page 44 DIAGNOSIS AND SOLUTION (CONT) Voltage protection error (E5) ERROR CODE MALFUNCTION DECISION An abnormal voltage rise or drop is detected by checking the specified voltage detection circuit. CONDITIONS • Power supply problems SUPPOSED CAUSES • System leakage or block • PCB faulty Troubleshooting Voltage Protection Check the voltage of...
  • Page 45 DIAGNOSIS AND SOLUTION (CONT) IPM board (for 2-zone /3-zone) Fig. 52 — IPM Board (for 2-zone/3-zone) Bridge rectifier (for 2-zone/3-zone) Remark: Measure the DC voltage between + and - port. The normal value should be 190V~250V. P(or E1/E2/E3)-N(GND) (for 2-zone/3-zone) Fig.
  • Page 46 DIAGNOSIS AND SOLUTION (CONT) Bridge rectifier (for 2-zone/3-zone) IPM Module (for 2-zone/3-zone) Fig. 54 — Bridge Rectifier (for 2-zone/3-zone) and IPM Module (for 2-zone/3-zone) IPM board (for 4-zone) Fig. 55 — IPM Board (for 4-zone) Specifications subject to change without notice. 38MGR-04SM...
  • Page 47 DIAGNOSIS AND SOLUTION (CONT) Bridge rectifier (for 5-zone) Remark: Measure the DC voltage between + and - port. The normal value should be 190V~250V. IPM board (for 5-zone) Fig. 56 — Bridge Rectifier (for 5-zone) IPM Module (for 5-zone) Fig. 57 — IPM Module (for 5 - zone) 38MGR-04SM Specifications subject to change without notice.
  • Page 48 DIAGNOSIS AND SOLUTION (CONT) PFC module protection error diagnosis and solution (E6) ERROR CODE MALFUNCTION DECISION When the voltage signal that PFC sends to main control board is abnormal, the display LED displays CONDITIONS “E6” and the AC turns off. •...
  • Page 49 DIAGNOSIS AND SOLUTION (CONT) Inductance Fig. 58 — Inductance Two ports of the inductance Fig. 59 — Inductance 38MGR-04SM Specifications subject to change without notice.
  • Page 50 DIAGNOSIS AND SOLUTION (CONT) Outdoor fan speed has been out of control (E8) ERROR CODE MALFUNCTION DECISION When the outdoor fan speed stays too low (300RPM) or too high (2400RPM) for certain time, the unit CONDITIONS stops and the LED displays the failure. •...
  • Page 51 DIAGNOSIS AND SOLUTION (CONT) Index 1: DC fan motor (control chip is inside fan motor) Power on and when the unit is in standby, measure the voltage of pin1-pin3, pin4-pin3 in fan motor connector. If the value of the voltage is not in the range showing in the table below, the PCB needs to be replaced.
  • Page 52 DIAGNOSIS AND SOLUTION (CONT) Temperature protection of compressor top) error (PO) ERROR CODE MALFUNCTION DECISION If the sampling voltage is not 5V, the LED displays the failure. CONDITIONS • Wiring mistake • Over load protector faulty SUPPOSED CAUSES • System block •...
  • Page 53 DIAGNOSIS AND SOLUTION (CONT) Fig. 62 — Test the voltage Fig. 63 — Test the voltage 38MGR-04SM Specifications subject to change without notice.
  • Page 54 DIAGNOSIS AND SOLUTION (CONT) High pressure protection error (P1) ERROR CODE MALFUNCTION DECISION If the sampling voltage is not 5V, the LED displays the failure. CONDITIONS • Wiring mistake • Over load protector faulty SUPPOSED CAUSES • System block • Outdoor PCB faulty Troubleshooting High Pressure Protection Is the wiring between the high...
  • Page 55 DIAGNOSIS AND SOLUTION (CONT) Fig. 64 —Test the voltage 38MGR-04SM Specifications subject to change without notice.
  • Page 56 DIAGNOSIS AND SOLUTION (CONT) Low pressure protection error (P2) ERROR CODE MALFUNCTION DECISION If the sampling voltage is not 5V, the LED displays the failure. CONDITIONS • Wiring mistake • Over load protector faulty SUPPOSED CAUSES • System block • Outdoor PCB faulty Troubleshooting Low Pressure Protection Is the wiring between the low...
  • Page 57 DIAGNOSIS AND SOLUTION (CONT) Fig. 65 — Test the voltage 38MGR-04SM Specifications subject to change without notice.
  • Page 58 DIAGNOSIS AND SOLUTION (CONT) Current protection of compressor error (P3) ERROR CODE MALFUNCTION DECISION If the outdoor current exceeds the current limit value, the LED displays the failure. CONDITIONS • Wiring mistake • Over load protector faulty SUPPOSED CAUSES • System block •...
  • Page 59 DIAGNOSIS AND SOLUTION (CONT) Fig. 66 — Test the voltage 38MGR-04SM Specifications subject to change without notice.
  • Page 60 DIAGNOSIS AND SOLUTION (CONT) Temperature protection of compressor discharge error (P4) ERROR CODE ° MALFUNCTION DECISION When the compressor discharge temperature (T5) is more than 239 F for ten seconds, the compressor ° CONDITIONS stops and restarts when T5 is less than 194 •...
  • Page 61 DIAGNOSIS AND SOLUTION (CONT) High temperature protection of condenser error (P5) ERROR CODE MALFUNCTION DECISION When the outdoor pipe temperature is more than 149°F, the unit stops, and unit runs again when the CONDITIONS outdoor pipe temperature is less than 125°F •...
  • Page 62 DIAGNOSIS AND SOLUTION (CONT) IPM module protection error (P6) ERROR CODE MALFUNCTION DECISION When the voltage signal that IPM send to compressor drive chip is abnormal, the display LED displays CONDITIONS “P6” and the AC turns off. • Wiring mistake •...
  • Page 63 DIAGNOSIS AND SOLUTION (CONT) The cooling operation or heating operation does not operate Probable cause: 4-way valve faulty Check the 4-way valve. See “4-Way Valve” on page 68 for more information. When cooling, the heat exchanger of the non-operating indoor unit frosts. When heating, the non-operating indoor unit gets warm. Probable causes: •...
  • Page 64: Appendices

    APPENDICES Appendix 1 Table 33 — Temperature Sensor Resistance Value (C-K) °C °F K OHM °C °F K OHM °C °F K OHM °C °F K OHM 115.266 12.6431 2.35774 0.62973 108.146 12.0561 2.27249 0.61148 101.517 11.5 2.19073 0.59386 96.3423 10.9731 2.11241 0.57683...
  • Page 65 Appendix 2 Table 34 — Unit C Discharge Temperature Sensor (°C-K) K OHM K OHM K OHM K OHM °C °F °C °F °C °F °C °F 542.7 68.66 13.59 3.702 511.9 65.62 13.11 3.595 62.73 12.65 3.492 455.9 59.98 12.21 3.392 430.5...
  • Page 66 Compressor Check Measure the resistance value of each winding by using the tester. Fig. 68 — Measure the Resistance Table 36 — Compressor Check POSITION RESISTANCE VALUE COMPRESSOR ATM150D23UFZ ATF235D22UMT ATF250D22UMT ATF310D43UMT ATQ360D1UMU BLUE - RED 1.72 Ω 0.75 Ω 0.75 Ω...
  • Page 67 IPM Continuity Check Turn off the power, let the large capacity electrolytic capacitors discharge completely, and dismount the IPM. Use a digital tester to measure the resistance between P and UVWN; UVW and N. Table 37 — IPM Continuity Check DIGITAL TESTER NORMAL RESISTANCE VALUE DIGITAL TESTER...
  • Page 68: Way Valve

    4-Way Valve 1. Power on. Use a digital tester to measure the voltage. When the unit operates in cooling, it is 0V. When the unit operates in the Heating mode, it is about 230VAC. If the value of the voltage is not in the range, the PCB needs to be replaced. Fig.
  • Page 69 EXV Check 1. Disconnect the connectors. Fig. 73 — Disconnect the connectors Fig. 74 — Disconnect the connectors Table 40 — Resistance to EXV Coil LEAD WIRE COLOR NORMAL VALUE Red - Blue Red - Yellow About 50Ω Brown - Orange Brown - White 38MGR-04SM Specifications subject to change without notice.
  • Page 70 EXV Check (CONT) Fig. 75 — EXV Check Specifications subject to change without notice. 38MGR-04SM...
  • Page 71 EXV Check (CONT) Brown-Orange Brown-White 38MGR-04SM Specifications subject to change without notice.
  • Page 72: Disassembly Instructions Size 18

    DISASSEMBLY INSTRUCTIONS SIZE 18 No. Part name Procedures Remarks How to remove the fan assembly. assembly 1) Turn off the air conditioner and turn off the power breaker. 2) Remove the screws (4) of the air outlet grille. 3) Remove hex nut securing the fan.
  • Page 73 DISASSEMBLY INSTRUCTIONS SIZE 18 (CONT) Remove the electrical control box cover. Disconnect the fan motor connector CN14 (3p, white) from the IPM board. 8) Remove the fan motor after unfastening the screws (4). Panel plate How to remove the panel plate. Front panel screws 1) Remove the front panel screws (6) then remove the...
  • Page 74 DISASSEMBLY INSTRUCTIONS SIZE 18 (CONT) Front panel screws 2) Remove the big handle screws (4), and remove the big handle. 3) Remove the terminal board Big handle screws (2) and the right-rear screws panel screws (7), then remove the right rear panel. Terminal board screws Right-rear...
  • Page 75 DISASSEMBLY INSTRUCTIONS SIZE 18 (CONT) Electrical How to remove the electrical parts parts. Complete the steps in the “Fan Assembly” and “Panel Plate” sections. 2) Remove the four (4) screws securing the IPM board. IPM board PCB board 3) Unfasten the reactor connector.
  • Page 76 DISASSEMBLY INSTRUCTIONS SIZE 18 (CONT) Connectors: CN15 CN17 7 CN18/CN19 9 CN25/CN23 CN17:T3/T4 temperature sensor (2p/2p,white) CN7: Discharge temperature (2p,white) CN15:T2B-A,B temperature sensor (2p/2p,white) CN18/CN19: Electronic expansion valve A,B (6p/6p,red/red) CN25/CN23: S-A,S-B (3p/3p,white/white) Wires: CN5/CN6 CN1/CN2 CN1/CN2: 4-way valve (blue-blue) CN5/CN6: Crankcase heating cable (red-red) CN3:L-IN (red)
  • Page 77 DISASSEMBLY INSTRUCTIONS SIZE 18 (CONT) Compressor How to remove the compressor 1) Complete the steps in the “Fan Assembly” and “Panel Plate” sections for size 18. 2) Remove the electrical control box cover. 3) Extract the refrigerant gas. Remove the sound insulation material and crankcase heating cable.
  • Page 78 DISASSEMBLY INSTRUCTIONS SIZE 18 (CONT) Reactor How to remove the reactor Complete the steps in the “Panel Plate”section for size 18. Unfasten the connector between the IPM and the reactor. Remove the reactor’s screws (3) and remove the reactor. Inductance cover screws The 4-way How to remove the 4-way valve...
  • Page 79 DISASSEMBLY INSTRUCTIONS SIZE 18 (CONT) How to remove the expansion valve expansion valve 1) Complete the steps in the “Fan Assembly” and “Panel Plate” sections. Expansion 2) Remove the electrical parts valves per the “Electrial Parts” section. 3) Remove the coils. Coils 4) Detach the welded parts of the expansion valves and...
  • Page 80: Disassembly Instructions Size 24

    DISASSEMBLY INSTRUCTIONS SIZE 24 Part name Procedures Remarks Panel plate How to remove the panel plate Top cover screws Big handle screws Turn off the air conditioner. Turn off the power breaker. Remove the big handle screws (4), then remove the big handle.
  • Page 81 DISASSEMBLY INSTRUCTIONS SIZE 24 (CONT) Right front side Front panel screws panel screws Front panel screws Remove the terminal board screws (2), the water collector screws, and the right-rear panel screws (15) and then remove the right-rear panel. Front panel screws Front panel screws 38MGR-04SM Specifications subject to change without notice.
  • Page 82 DISASSEMBLY INSTRUCTIONS SIZE 24 (CONT) Right-rear panel screws Terminal board screws Specifications subject to change without notice. 38MGR-04SM...
  • Page 83 DISASSEMBLY INSTRUCTIONS SIZE 24 (CONT) How to remove the fan assembly. assembly 1) Remove the top cover, right front side panel and the front panel. See “How to ”Remove the Panel Plate. 2) Remove the hex nut securing the fan. 3) Remove the fan.
  • Page 84 DISASSEMBLY INSTRUCTIONS SIZE 24 (CONT) Electrical How to remove the electrical parts parts. Complete the steps in the “Fan Assembly and ”Panel Plate” sections. Remove the screws (4) securing the IPM board. 3) Unfasten the reactor connector. IPM board PCB board 4) Unfasten the compressor connector.
  • Page 85 DISASSEMBLY INSTRUCTIONS SIZE 24 (CONT) 7) Disconnect the connectors CN15 CN7 CN17 and wires connected to the CN18/CN19/CN22 PCB and other parts. Connectors: CN17:T3/T4 temperature sensor (2p/2p,white) CN7: Discharge temperature sensor (2p,white) CN20 CN12:Ttop temperature CN23 sensor (2p,white) CN25 CN15:T2B-A,B,C temperature sensor (2p/2p/2p,white) CN18/CN19/CN22: Electronic expansion valve A,B,C...
  • Page 86 DISASSEMBLY INSTRUCTIONS SIZE 24 (CONT) Compressor How to remove the compressor 1) Complete steps in the “Panel Plate, Fan Assembly, and Electrical Parts sections. 2) Remove the electrical control box and partition plate. 3) Extract the refrigerant gas. 4) Remove the sound insulation material and crankcase heating cable.
  • Page 87 DISASSEMBLY INSTRUCTIONS SIZE 24 (CONT) Reactor How to remove the reactor 1) Compete the steps in the “Panel Plate and Fan Assembly” sections. 2) Unfasten the connector between the IPM and the reactor. 3) Remove the inductance cover screws (2) then Inductance remove the inductance cover screws...
  • Page 88 DISASSEMBLY INSTRUCTIONS SIZE 24 (CONT) How to remove the expansion expansion valve valve 1) Complete steps in the “Panel Plate and ”Fan Assembly” sections. Expansion Valves 2) Remove the electrical parts. See the “Electrical Parts” section. 3) Remove the coils. 4) Detach the welded parts of the expansion valves and the pipes.
  • Page 89: Disassembly Instructions Size 30

    DISASSEMBLY INSTRUCTIONS SIZE 30 No. Part name Procedures Remarks Panel plate How to remove the panel plate Big handle screws 1) Turn off the air conditioner. Turn off the power breaker. Top cover screws 2) Remove the big handle screws. 3) Remove the top cover screws and then remove the top cover (4 screws).
  • Page 90 DISASSEMBLY INSTRUCTIONS SIZE 30 (CONT) 5) Remove the front panel screws (8) and remove the front panel. Front panel screws Right front side panel screws 6) Remove the terminal board Front panel screws screws (2), the water collector screws, and the right-rear panel screws (15), and then remove the right-rear panel.
  • Page 91 DISASSEMBLY INSTRUCTIONS SIZE 30 (CONT) Right-rear panel screws Terminal board screws How to remove the fan assembly assembly 1) Remove the top cover, right front side panel and the front panel as described in the “Panel Plate” section. 2) Remove the hex nut securing the fan.
  • Page 92 DISASSEMBLY INSTRUCTIONS SIZE 30 (CONT) 3) Remove the fan. 4) Undo the hooks, remove the screws, and then open the electrical control box. 5) Disconnect the fan motor connector CN19 (3P, white) from the driver board. 6) Remove the screws (4) and then remove the fan motor.
  • Page 93 DISASSEMBLY INSTRUCTIONS SIZE 30 (CONT) 5) Disconnect the following three connection wires between the driver board and PCB. CN55-CN7(7p,white) CN54-CN6(red) CN53-CN5(black) 6) Remove the screws then remove the driver board. 7) Disconnect the connectors and wires from the PCB and CN53 other parts.
  • Page 94 DISASSEMBLY INSTRUCTIONS SIZE 30 (CONT) Wires: CN3/CN22: 4-way valve (blue-blue) CN13 CN4/CN40: Crankcase heating cable CN10 CN33 (black-red) CN22 CN40 CN10/CN44: Crankcase heating CN44 CN2 CN1 cable (black-red) CN1:L1-IN (red) CN2:L2-IN (black) 8) Disconnect the grounding wire (yellow-green) after removing the right-rear panel.
  • Page 95 DISASSEMBLY INSTRUCTIONS SIZE 30 (CONT) 6) Remove the discharge pipe and suction pipe with a burner. 7) Remove the hex nuts and washers securing the compressor to the bottom plate. 8) Lift the compressor. The 4-way How to remove the 4-way valve valve 1) Complete the steps in the Coil...
  • Page 96: Disassembly Instructions Sizes 36 And 48

    DISASSEMBLY INSTRUCTIONS SIZES 36 AND 48 Part name Procedures Remarks How to remove the fan assembly assembly 1) Turn off the air conditioner. Turn off the power breaker. 2) Remove the air outlet grille screws (8). 3) Remove the hex nut securing the fan.
  • Page 97 DISASSEMBLY INSTRUCTIONS SIZES 36 AND 48 (CONT) 6) Remove the front side panel screw (1), and then remove the front side panel. 7) Disconnect the fan motor connectors FAN1 (3p,white) and FAN2 (3p,white) from the DC motor driver board. 8) Remove the fan screws and remove the fan motor.
  • Page 98 DISASSEMBLY INSTRUCTIONS SIZES 36 AND 48 (CONT) 2) Remove the terminal board screws (2) and the right-rear Terminal Board panel screws (15) and then Screws remove the right-rear panel. Right-rear panel screws Right-rear panel screws Electrical How to remove the electrical parts parts.
  • Page 99 DISASSEMBLY INSTRUCTIONS SIZES 36 AND 48 (CONT) 3) Disconnect the following connection wires and connectors between the IPM and the other parts. CN2(yellow) CN1(red) CN6(black) CN3(yellow) U V W(black) CN9 (10p,white) 4) Remove the screws and then remove the IPM board. 5) Disconnect the connectors and wires connected from the PCB and the other parts.
  • Page 100 DISASSEMBLY INSTRUCTIONS SIZES 36 AND 48 (CONT) CN37/CN29/CN21/CN16/CN13: S-A,S-B,S-C,S-D,S-E (3p/3p/3p/3p/3p,white) CN10: High and low pressure switch (2p/2p, white) Wires: CN10 CN30/CN23 CN17/CN18: 4-way valve (blue-blue) CN19/CN20: connected to crankcase heating cable. (black-red) CN24/CN25: Electric heater of CN17/CN18 CN19/CN20 chassis (orange-orange) CN24/CN25 CN1:L-IN (red) CN3:N-IN (black)
  • Page 101 DISASSEMBLY INSTRUCTIONS SIZES 36 AND 48 (CONT) 5) Remove the discharge pipe and suction pipe with a burner. 6) Remove the hex nuts and washers securing the compressor to the bottom plate. 7) Lift the compressor. The 4-way How to remove the 4-way valve valve 1) Complete steps 5 and 6 in the Fan Assembly section...
  • Page 102 DISASSEMBLY INSTRUCTIONS SIZES 36 AND 48 (CONT) How to remove the expansion expansion valve valve 1) Complete the steps in the Fan Assembly and Panel Plate sections. Expansion valves 2) Remove the electrical parts as described in the Electrical Parts section. 3) Remove the coil.

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