Carrier 38MAQB24-3 User Manual

38MAQ
Outdoor Unit Single Zone Ductless System
Sizes 09 to 30
Service Manual
TABLE OF CONTENTS
PAGE
SAFETY CONSIDERATIONS 1.........................
INTRODUCTION 1...................................
MODEL/SERIAL NUMBER NOMENCLATURES 2.........
SPECIFICATIONS 3...................................
DIMENSIONS 4.....................................
CLEARANCES 7.....................................
PERFORMANCE 6...................................
ELECTRICAL DATA 8................................
WIRING 8...........................................
CONNECTION DIAGRAMS 9..........................
WIRING DIAGRAMS 10...............................
FAN AND MOTOR SPECIFICATIONS 15.................
REFRIGERANT COIL SPECIFICATIONS 16..............
REFRIGERATION CYCLE DIAGRAMS 17................
REFRIGERANT LINES 18.............................
SYSTEM EVACUATION AND CHARGING 19.............
ELECTRONIC FUNCTION 20..........................
TROUBLESHOOTING 21..............................
DIAGNOSTIC GUIDES 23.............................
DIAGNOSIS AND SOLUTION 29.......................
APPENDIX 46.......................................
DISASSEMBLY INSTRUCTIONS 52.....................
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 38MAQB24-3 Specifications

General

Energy Efficiency Ratio (EER)	12.5
Refrigerant	R-410A
Operating Temperature (Cooling)	5°F to 122°F
Type	Ductless Mini Split
Cooling Capacity	24000 BTU/h
Heating Capacity	24000 BTU/h
Power Supply	208/230V, 1 Phase, 60 Hz
Outdoor Unit Noise Level	55 dB

Summary

Safety Considerations

Hazard Signal Words

Defines hazard signal words used to alert users to potential injury or damage.

Clearances for Outdoor Units

Outdoor Unit Clearance Requirements

Electrical Data and Wiring

Electrical Specifications by Unit Size

Lists electrical data including voltage, MCA, MOCP, RLA, and FLA for different unit sizes.

Power and Communication Wiring Guidelines

Fan and Motor Specifications

Outdoor Fan Motor Specifications

Refrigeration Cycle Diagrams

Heat Pump Refrigerant Cycle Diagram

Illustrates the refrigerant flow through the indoor and outdoor units for heat pump operation.

Refrigerant Lines

General Refrigerant Line Sizing Guidelines

Provides guidelines for sizing refrigerant lines, including minimum lengths and insulation requirements.

Piping and Refrigerant Information Table

Lists maximum piping lengths, additional refrigerant charge, and pipe sizes for various unit configurations.

Long Line Applications Guidance

Details refrigerant charge adjustments for longer piping runs.

System Evacuation and Charging

Evacuation Using a Vacuum Pump

Outlines the procedure for evacuating the system using a vacuum pump.

Deep Vacuum Method Procedure

Explains the deep vacuum method for system evacuation, emphasizing micron levels.

Triple Evacuation Method Procedure

Describes the alternate triple evacuation method using nitrogen to remove moisture.

Electronic Function and Protection

Main Protection Features

Details protection functions like compressor restart delay, temperature protection, and fan speed control.

Condenser Temperature Protection

Describes protection triggered by high condenser temperature, affecting compressor operation.

Evaporator Temperature Protection

Explains protection that stops the compressor when evaporator temperature is too low.

Diagnostic Guides for Indoor Units

Indoor Unit Diagnostic Codes and LED Status

Lists diagnostic codes (E0-E5, EC, F0-F5, P0-P4) for indoor units and their corresponding LED status.

Outdoor Unit Error Display (09-12, 115V)

Outdoor Unit Error Display (09-12, 208-230V)

Outdoor Unit Error Display (Size 18)

Error Codes and LED Indicators for Size 18

Lists error codes, LED status (Green/Red), and corresponding IU display for Size 18 units.

Outdoor Unit Error Display (Size 24)

Outdoor Unit Error Display (Size 30)

Diagnosis and Solution

EEPROM Parameter Error (E0/F4) Troubleshooting

Troubleshooting steps for EEPROM parameter errors, including PCB checks and replacement.

Diagnosis and Solution (Continued)

Communication Error (E1) Troubleshooting

Troubleshooting for communication errors between indoor and outdoor units, covering wiring and PCB checks.

DC Voltage and Reactor Testing

Zero Crossing Detection Error (E2) Troubleshooting

Troubleshooting steps for zero crossing detection errors, focusing on connections and PCB faults.

Fan Speed Control Error (E3/F5) Troubleshooting

Troubleshooting for fan speed control issues, including wiring, motor, and PCB checks.

DC Fan Motor Voltage Check Procedure

Details voltage measurements for DC fan motors to diagnose PCB or motor issues.

Temperature Sensor Circuit Error (E4/E5/F1/F2/F3) Troubleshooting

Guides on troubleshooting temperature sensor circuit errors, checking connections, resistance, and PCB.

Refrigerant Leakage Detection (EC) Troubleshooting

Provides troubleshooting for refrigerant leakage detection, including sensor checks and system repairs.

Overload Current Protection (F0) Troubleshooting

Details troubleshooting for overload current protection, covering power supply, blockages, wiring, and compressor issues.

IPM Malfunction / IGBT Over-Current Protection (P0) Troubleshooting

Offers troubleshooting for IPM or IGBT over-current protection, checking wiring, IPM, fan, and compressor.

IPM Voltage Measurement (P-U, P-V)

IPM Voltage Measurement (P-W, N-U)

IPM Voltage Measurement (N-V, N-W)

Over Voltage / Low Voltage Protection (P1) Troubleshooting

Provides troubleshooting for over/under voltage protection, checking power, wiring, voltage, and reactor.

High Temperature Protection (P2) Troubleshooting

Guides on troubleshooting high temperature protection for the compressor, checking airflow, temperature, and OLP.

Inverter Compressor Drive Error (P4) Troubleshooting

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

Compressor Checking

Compressor Winding Resistance Check

IPM Continuity Check

Digital Tester Resistance Measurement for IPM

Disassembly Instructions (Sizes 09-12)

Panel Plate Removal (09-12)

Disassembly Instructions (Sizes 09-12) (Continued)

Fan Assembly Removal (09-12)

Fan Motor Removal (09-12)

Electrical Parts Removal (09-12)

Four-Way Valve Removal (09-12)

Compressor Removal (09-12)

Disassembly Instructions (Size 18K)

Panel Plate Removal (18K)

Disassembly Instructions (Size 18K) (Continued)

Side Plate Removal (18K)

Fan Assembly Removal (18K)

Electrical Parts Removal (18K)

Reactor and Power Supply Removal (18K)

Four-Way Valve and Compressor Removal (18K)

Disassembly Instructions (Sizes 24K-30K)

Panel Plate Removal (24K-30K)

Disassembly Instructions (Sizes 24K-30K) (Continued)

Side Plate and Control Box Removal (24K-30K)

Fan Assembly Removal (24K-30K)

Fan Motor and Compressor Connector Removal (24K-30K)

IPM Board and Sensor Connector Removal (24K-30K)

Sensor and Control Box Removal (24K-30K)

Four-Way Valve Removal (24K-30K)

Compressor Removal (24K-30K)