Carrier 38MHRB series User Manual

Service Manual
38MHRB
Outdoor Unit Single Zone Ductless System
Sizes 09 to 24
TABLE OF CONTENTS
PAGE
SAFETY CONSIDERATIONS 1.........................
INTRODUCTION 1...................................
MODEL/SERIAL NUMBER NOMENCLATURES 2.........
SPECIFICATIONS 3...................................
DIMENSIONS 5.....................................
CLEARANCES 8.....................................
ELECTRICAL DATA 9................................
WIRING 9...........................................
CONNECTION DIAGRAMS 10.........................
WIRING DIAGRAMS 11...............................
REFRIGERATION CYCLE DIAGRAMS 17................
REFRIGERANT LINES 18.............................
SYSTEM EVACUATION AND CHARGING 19.............
ELECTRONIC FUNCTIONS 18.........................
TROUBLESHOOTING 23..............................
OUTDOOR UNIT DIAGNOSTIC GUIDES 24..............
PCB DIAGRAMS 25..................................
DIAGNOSIS AND SOLUTION 27.......................
DISASSEMBLY INSTRUCTIONS 48.....................
APPENDIX 71.......................................
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 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 setting bulky equipment.
Read this manual thoroughly and follow all warnings or cautions
included in 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
!
!
.
When you see this symbol on the unit and in instructions or manuals,
be alert to the potential for personal injury. Understand these signal
words: DANGER, WARNING, and CAUTION.
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.
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.
!
WARNING
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 outdoor units. Section 2 of this manual has
an appendix with data required to perform troubleshooting. Use the
Table of Contents to locate a desired topic.

Carrier 38MHRB series Specifications

General

Brand	Carrier
Model	38MHRB series
Category	Air Conditioner
Language	English

Summary

SAFETY CONSIDERATIONS

Electrical Shock Hazard Warning

Warning about severe personal injury or death from electrical shock during service.

Explosion Hazard Warning

Warning about severe personal injury, death, or property damage from gas mixtures.

Equipment Damage Hazard Caution

Caution regarding potential equipment damage or improper operation due to specific practices.

MODEL/SERIAL NUMBER NOMENCLATURES

Outdoor Unit Model Structure

Explanation of how model numbers are structured for outdoor units.

SPECIFICATIONS (Cooling Only)

Cooling Unit Specifications

Detailed specifications for cooling-only outdoor units across various sizes.

SPECIFICATIONS (Heat Pump)

Heat Pump Unit Specifications

Detailed specifications for heat pump outdoor units across various sizes.

DIMENSIONS

Unit Dimensions and Weights

Table showing physical dimensions and net weights for various unit sizes.

OUTDOOR UNIT DIMENSIONS

18K Heat Pump Unit Dimensions

Diagram illustrating the dimensions of the 18K Heat Pump outdoor unit.

OUTDOOR UNIT DIMENSIONS (CONTINUED)

24K Unit Dimensions

Diagram illustrating the dimensions of the 24K outdoor unit.

CLEARANCES

Outdoor Unit Clearance Requirements

Specifies minimum clearance values for outdoor unit installation and airflow.

ELECTRICAL DATA

Unit Electrical Specifications

Electrical data including voltage, MCA, MOCP, RLA, FLA, and HP for unit sizes.

WIRING

Recommended Power & Communication Wiring

Guidelines for connecting power and communication wires between units.

CONNECTION DIAGRAMS

115V and 230V Wiring Connections

Diagrams illustrating electrical connections for 115V and 230V indoor and outdoor units.

WIRING DIAGRAMS (COOLING ONLY)

12K (115V) Cooling Wiring Diagram

Detailed wiring diagram for the 12K Cooling Only unit operating on 115V.

WIRING DIAGRAMS (COOLING ONLY) (CONT.)

12K (230V) Cooling Wiring Diagram

Detailed wiring diagram for the 12K Cooling Only unit operating on 230V.

WIRING DIAGRAMS (COOLING ONLY) (CONT.)

18-24K Cooling Wiring Diagram

Detailed wiring diagram for 18K and 24K Cooling Only units.

WIRING DIAGRAMS (HEAT PUMP)

12K (115V) Heat Pump Wiring Diagram

Detailed wiring diagram for the 12K Heat Pump unit operating on 115V.

WIRING DIAGRAMS (HEAT PUMP) (CONT.)

09, 12, 18 (230V) Heat Pump Wiring Diagram

Detailed wiring diagram for 09K, 12K, and 18K Heat Pump units on 230V.

WIRING DIAGRAMS (HEAT PUMP) (CONT.)

24 (230V) Heat Pump Wiring Diagram

Detailed wiring diagram for the 24K Heat Pump unit operating on 230V.

REFRIGERATION CYCLE DIAGRAMS

Heat Pump Refrigeration Cycle Diagram

Diagram illustrating the refrigeration cycle for heat pump models.

REFRIGERANT LINES

General Refrigerant Line Sizing

Guidelines for sizing refrigerant lines, including lengths and insulation requirements.

Long Line Applications

Information for systems with extended refrigerant line lengths, including adjustments.

SYSTEM EVACUATION AND CHARGING

Vacuum Pump Evacuation Procedure

Step-by-step guide for evacuating the system using a vacuum pump.

Deep Vacuum & Triple Evacuation Methods

Explanation of deep vacuum and triple evacuation methods for system evacuation.

Final Tubing Check

Important final check of refrigerant tubing connections and security.

OPERATION MODES AND FUNCTIONS

FAN and COOLING Modes

Details on FAN mode operation and compressor/fan rules for COOLING mode.

Compressor & Fan Running Rules

Rules governing compressor and outdoor fan operation based on temperature and settings.

OPERATION MODES AND FUNCTIONS (CONT.)

HEATING, DEFROST, and AUTO Modes

Explains auto fan action in HEATING, DEFROST mode, and AUTO mode operation.

Temperature Protections & DRY Mode

Covers Evaporator Coil Protection, DRY mode, and low room temp. protection.

Forced Operation & Auto-Restart

Details on Forced Operation, Forced Cooling, and the AUTO-RESTART function.

Refrigerant Leak Detection

Describes the function of refrigerant leak detection and its display codes.

POINT CHECK FUNCTION

Information Enquiry Codes and Values

Lists codes displayed during information enquiry and their corresponding values/meanings.

TROUBLESHOOTING

Electrolytic Capacitor Safety

Safety precautions for handling electrolytic capacitors, including discharge procedures.

OUTDOOR UNIT DIAGNOSTIC GUIDES

LED Status and Error Codes

Table correlating operation/timer lamp status with diagnostic codes and LED status.

PCB DIAGRAMS

115V and 208-230V PCB Layouts

Diagrams showing component layout for 115V and 208-230V outdoor unit PCBs.

PCB DIAGRAMS (CONT.)

18-24 208-230V PCB Layout & LED Codes

PCB layout for 18-24K units and table of LED error codes.

DIAGNOSIS AND SOLUTION

EEPROM Parameter Error (E0/F4)

Troubleshooting steps for EEPROM parameter errors, including PCB replacement.

DIAGNOSIS AND SOLUTION (CONT.)

Communication Error (E1)

Diagnosis and solution for indoor/outdoor unit communication errors, checking wiring and components.

DIAGNOSIS AND SOLUTION (CONT.)

Testing DC Voltage and Reactor Resistance

Procedures for testing DC voltage and reactor resistance using a multimeter.

DIAGNOSIS AND SOLUTION (CONT.)

Zero Crossing Detection Error (E2)

Troubleshooting steps for zero crossing detection errors, checking connections and PCB.

DIAGNOSIS AND SOLUTION (CONT.)

Fan Speed Control Error (E3/F5)

Diagnosis and solution for indoor fan speed control issues, checking wiring, fan motor, and PCB.

DIAGNOSIS AND SOLUTION (CONT.)

DC and AC Fan Motor Checks

Procedures for checking indoor/outdoor DC and AC fan motors, including voltage and resistance tests.

DIAGNOSIS AND SOLUTION (CONT.)

Temperature Sensor Circuit Errors (E4/E5/F1/F2/F3)

Troubleshooting for temperature sensor open/short circuits, checking connections, sensors, and PCB.

DIAGNOSIS AND SOLUTION (CONT.)

Refrigerant Leakage Detection (EC)

Diagnosis and solution for refrigerant leakage detection, checking sensors and system integrity.

DIAGNOSIS AND SOLUTION (CONT.)

Overload Current Protection (F0)

Troubleshooting steps for overload current protection, checking power, blockages, compressor, and reactor.

DIAGNOSIS AND SOLUTION (CONT.)

IPM Malfunction / Over-Current Protection (P0)

Diagnosis and solution for IPM malfunction or over-current protection, checking wiring, IPM, fan, and compressor.

DIAGNOSIS AND SOLUTION (CONT.)

IPM Testing Procedures (P-U, P-V)

Visual guide for performing IPM testing steps P-U and P-V using a multimeter.

DIAGNOSIS AND SOLUTION (CONT.)

IPM Testing Procedures (P-W, N-U)

Visual guide for performing IPM testing steps P-W and N-U using a multimeter.

DIAGNOSIS AND SOLUTION (CONT.)

IPM Testing Procedures (N-V, N-W)

Visual guide for performing IPM testing steps N-V and N-W using a multimeter.

DIAGNOSIS AND SOLUTION (CONT.)

Over/Under Voltage Protection (P1)

Troubleshooting for over/under voltage protection, checking power, connections, voltage, and reactor.

DIAGNOSIS AND SOLUTION (CONT.)

Compressor Top High Temp. Protection (P2)

Diagnosis for compressor top high temp. protection, checking screws, airflow, connections, OLP sensor, and refrigerant.

DIAGNOSIS AND SOLUTION (CONT.)

Inverter Compressor Drive Error (P4)

Troubleshooting for inverter compressor drive errors, checking wiring, IPM, fan, and compressor.

DIAGNOSIS AND SOLUTION (CONT.)

Temperature Sensor Resistance Check

Procedure for checking temperature sensor resistance values using a tester.

DIAGNOSIS AND SOLUTION (CONT.)

Compressor Resistance Check

Procedure for checking compressor winding resistance values using a tester.

DIAGNOSIS AND SOLUTION (CONT.)

IPM and Fan Motor Continuity Checks

Procedures for checking IPM continuity and fan motor winding resistance.

PRESSURE ON SERVICE PORT

Cooling Mode Pressure Charts

Charts showing service port pressures for various outdoor/indoor temperatures in cooling mode.

PRESSURE ON SERVICE PORT (CONT.)

Heating Mode Pressure Charts

Charts showing service port pressures for various outdoor/indoor temperatures in heating mode.

DISASSEMBLY INSTRUCTIONS

12K (115V) Unit Panel Plate Removal

Steps for removing the panel plate from the 12K (115V) outdoor unit.

DISASSEMBLY INSTRUCTIONS (CONT.)

12K (115V) Unit Fan Assembly Removal

Steps for removing the fan assembly from the 12K (115V) outdoor unit.

DISASSEMBLY INSTRUCTIONS (CONT.)

12K (115V) Unit Electrical Parts Removal

Steps for removing electrical components from the 12K (115V) outdoor unit.

DISASSEMBLY INSTRUCTIONS (CONT.)

Four-way Valve & Compressor Removal

Steps for removing the four-way valve and the compressor from the unit.

DISASSEMBLY INSTRUCTIONS

12K (208-230V) Unit Panel Plate Removal

Steps for removing the panel plate from the 12K (208-230V) outdoor unit.

DISASSEMBLY INSTRUCTIONS (CONT.)

12K (208-230V) Unit Fan Assembly Removal

Steps for removing the fan assembly from the 12K (208-230V) outdoor unit.

DISASSEMBLY INSTRUCTIONS (CONT.)

Four-way Valve & Compressor Removal (208-230V)

Steps for removing the four-way valve and compressor from the 208-230V unit.

DISASSEMBLY INSTRUCTIONS

18K (208-230V) Unit Panel Plate Removal

Steps for removing the panel plate from the 18K (208-230V) outdoor unit.

DISASSEMBLY INSTRUCTIONS (CONT.)

18K (208-230V) Unit Fan Assembly Removal

Steps for removing the fan assembly from the 18K (208-230V) outdoor unit.

DISASSEMBLY INSTRUCTIONS (CONT.)

18K (208-230V) Unit Electrical Parts Removal

Steps for removing electrical components from the 18K (208-230V) outdoor unit.

DISASSEMBLY INSTRUCTIONS (CONT.)

Four-way Valve & Compressor Removal (18K)

Steps for removing the four-way valve and compressor from the 18K unit.

DISASSEMBLY INSTRUCTIONS

24K (208-230V) Unit Panel Plate Removal

Steps for removing the panel plate from the 24K (208-230V) outdoor unit.

DISASSEMBLY INSTRUCTIONS (CONT.)

24K (208-230V) Unit Fan Assembly Removal

Steps for removing the fan assembly from the 24K (208-230V) outdoor unit.

DISASSEMBLY INSTRUCTIONS (CONT.)

24K (208-230V) Unit Electrical Parts Removal

Steps for removing electrical components from the 24K (208-230V) outdoor unit.

DISASSEMBLY INSTRUCTIONS (CONT.)

Four-way Valve & Compressor Removal (24K)

Steps for removing the four-way valve and compressor from the 24K unit.

APPENDIX

Temperature Sensor Resistance Values (T1-T4)

Table providing resistance values for temperature sensors T1, T2, T3, and T4 at various temperatures.

APPENDIX (CONT.)

Temperature Sensor Resistance Values (T5)

Table providing resistance values for temperature sensor T5 at various temperatures.

APPENDIX (CONT.)

Celsius to Fahrenheit Conversion Table

Table for converting Celsius temperatures to Fahrenheit.