Carrier 38MHRCQ18AA3 - User Manual

Specifications subject to change without notice.
TABLE OF CONTENTS
PAGE
SAFETY CONSIDERATIONS ....................................................... 1
INTRODUCTION............................................................................ 1
MODEL / SERIAL NUMBER NOMENCLATURES .................... 2
SPECIFICATIONS (HEAT PUMP)................................................ 3
PERFORMANCE ............................................................................ 4
DIMENSIONS AND WEIGHTS .................................................... 5
CLEARANCES................................................................................ 9
ELECTRICAL DATA ..................................................................... 10
WIRING........................................................................................... 10
CONNECTION DIAGRAMS ......................................................... 11
WIRING DIAGRAMS (HEAT PUMP) .......................................... 12
REFRIGERATION CYCLE DIAGRAMS...................................... 15
SYSTEM EVACUATION AND CHARGING ............................... 20
TROUBLESHOOTING................................................................... 27
DIAGNOSIS AND SOLUTION...................................................... 31
DISASSEMBLY INSTRUCTIONS SIZES 9K (115V) - 18K (208/
230V)................................................................................................ 51
DISASSEMBLY INSTRUCTIONS SIZE 24K............................... 54
APPENDIX ...................................................................................... 57
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 . 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.
INTRODUCTION
This service manual provides the necessary information to service,
repair, and maintain the outdoor units. This manual has an appendix
with data required to perform troubleshooting. Use the “Table of
Contents” to locate a desired topic.
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.
WAR N I N G
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.
WAR N I N G
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.
CAUTION
Service Manual
38MHRC
Outdoor Unit Single Zone Ductless System
Sizes 09 to 24

Summary

SAFETY CONSIDERATIONS

Electrical Shock Hazard

Warning about electrical hazards during installation and servicing.

Explosion Hazard

Warning about explosion risks from pressurized gas mixtures.

Equipment Damage Hazard

Caution against practices that could damage equipment.

Signal Words Explanation

Defines DANGER, WARNING, and CAUTION for safety information.

MODEL; SERIAL NUMBER NOMENCLATURES

SPECIFICATIONS (HEAT PUMP)

PERFORMANCE

DIMENSIONS AND WEIGHTS

CLEARANCES

ELECTRICAL DATA

WIRING GUIDELINES

Instructions for power and communication wiring connections.

ELECTRICAL SAFETY CAUTIONS

Warnings regarding wiring practices and local codes.

CONNECTION DIAGRAMS

WIRING DIAGRAMS

REFRIGERATION CYCLE DIAGRAMS

REFRIGERANT LINES

General Refrigerant Line Sizing

Guidelines for selecting appropriate refrigerant line sizes.

Long-Line Applications

Considerations for extended refrigerant line installations.

SYSTEM EVACUATION AND CHARGING

Deep Vacuum Method

Procedure for achieving a deep vacuum in the system.

Triple Evacuation Method

Step-by-step process for triple evacuation.

ELECTRONIC FUNCTIONS

Protection Features

Details on various protection mechanisms for the unit.

Operating Modes and Rules

Explains FAN, COOLING, HEATING, AUTO modes and their rules.

DEFROST Mode

Forced Defrosting

Procedure to manually activate the defrost mode.

ADDITIONAL SYSTEM FUNCTIONS

Special Modes and Features

Covers Drying mode, forced operation, auto-restart, leakage detection, heating.

POINT CHECK FUNCTION

TROUBLESHOOTING

Capacitor Safety Precautions

Warnings regarding capacitor discharge before troubleshooting.

OUTDOOR UNIT DIAGNOSTIC GUIDE

PCB DIAGRAMS

DIAGNOSIS AND SOLUTION

EEPROM Parameter Error (E0;F4)

Troubleshooting steps for EEPROM parameter errors.

Indoor;Outdoor Unit Communication Error (E1)

Steps to resolve communication errors between units.

Zero Crossing Detection Error (E2)

Diagnosis and solution for zero crossing detection issues.

Indoor Fan Speed Errors (E3;F5)

Troubleshooting for abnormal indoor fan speed conditions.

Fan Motor Diagnosis

Procedures for diagnosing indoor and outdoor fan motor faults.

Temperature Sensor Errors (E4;E5;F1;F2;F3)

Troubleshooting sensor open/short circuits.

Refrigerant Leakage Detection (EC)

Diagnosis and solution for refrigerant leakage detection.

Overload Current Protection (F0)

Troubleshooting steps for overload current protection.

IPM;IGBT Over-current Protection (P0)

Diagnosis for IPM or IGBT over-current protection faults.

Over;Under Voltage Protection (P1)

Troubleshooting voltage protection errors.

Compressor Top Temperature Protection (P2)

Diagnosis for compressor top high-temperature protection.

Inverter Compressor Drive Error (P4)

Troubleshooting inverter compressor drive errors.

Main Parts Check

Procedures for checking critical system components.

Compressor Checking

Method for checking compressor winding resistance.

IPM Continuity Check

Procedure to test IPM continuity.

Fan Motor Check

Method for measuring fan motor winding resistance.

PRESSURE ON THE SERVICE PORT

Cooling Chart

Service port pressure values for cooling operation.

Heating Chart

Service port pressure values for heating operation.

DISASSEMBLY INSTRUCTIONS

Sizes 9 K (115 V) - 18 K (208;230 V)

Steps to disassemble specific outdoor unit sizes.

Size 24 K

Steps to disassemble the size 24K outdoor unit.

APPENDIX

Temperature Sensor Resistance Table

Resistance values for T1, T2, T3, T4 sensors.

T5 Temperature Sensor Resistance Table

Resistance values for T5 sensor.

Carrier 38MHRCQ18AA3 Specifications

General

Brand	Carrier
Model	38MHRCQ18AA3
Category	Air Conditioner
Language	English