Carrier 38MBRQ48A-3 - User Manual

Specifications subject to change without notice.
TABLE of CONTENTS
PAGE
SA\FETY CONSIDERATIONS ...................................................... 1
INTRODUCTION............................................................................ 1
MODEL / SERIAL NUMBER NOMENCLATURES .................... 2
WIRING........................................................................................... 3
CONNECTION DIAGRAM............................................................ 3
WIRING DIAGRAMS..................................................................... 4
REFRIGERATION CYCLE DIAGRAM........................................ 8
REFRIGERANT LINES .................................................................. 9
SYSTEM EVACUATION AND CHARGING ............................... 10
SYSTEM VACUUM AND CHARGE ............................................ 10
ELECTRONIC FUNCTIONS ......................................................... 11
POINT CHECK FUNCTION .......................................................... 14
TROUBLESHOOTING................................................................... 16
DIAGNOSTIC GUIDES.................................................................. 17
DIAGNOSIS AND SOLUTION...................................................... 18
DISASSEMBLY INSTRUCTIONS SIZE 36.................................. 47
DISASSEMBLY INSTRUCTIONS SIZE 48-58 ............................ 53
SA\FETY 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 38MBR family of heat pumps. Use the
“TABLE of CONTENTS” on page 1 to locate a desired topic. For
detailed information regarding product specifications refer to product
data documentation.
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.
WA RNING
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.
WA RNING
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
38MBR
Outdoor Unit Single Zone Ductless System
Sizes 36 to 58

Summary

Safety Considerations and Introduction

Safety Alert Symbols and Hazards

Identifies DANGER, WARNING, CAUTION meanings and specific hazards like electrical shock and explosion.

Equipment Damage Precautions

Cautions regarding pipe burial and general equipment handling.

System Evacuation and Charging

Vacuum Pump Evacuation Method

Step-by-step guide on using a vacuum pump to evacuate the system.

Deep Vacuum and Triple Evacuation

Evacuation Procedure Diagrams

Defrosting Mode Operations

Defrost Trigger and Measurement Conditions

Defrost Exit Criteria

Defrosting Process Chart

Unit Protections and Diagnostics

Evaporator Coil Temperature Protection

Diagram illustrating evaporator coil temperature protection states: Off, Decrease, Hold, Resume.

Troubleshooting Procedures

Required Tools for Diagnosis

Troubleshooting Steps and Guidelines

Control Board Measurement Precautions

Diagnostic Error Guides

Indoor Unit Error Display Table

Lists indoor unit error codes, LED status, and corresponding solutions with page references.

Wired Controller Error Display Table

Lists error codes displayed on the wired controller and their solutions.

Outdoor Unit Diagnosis and Solutions

Outdoor Unit Error Code Guide

Table correlating outdoor unit problems with error codes and solutions.

EEPROM Parameter Error Diagnosis (E0;F4)

Troubleshooting EEPROM Errors

Steps to diagnose and resolve EEPROM parameter errors, including PCB replacement.

Overload Current Protection Diagnosis (F0)

Troubleshooting Overload Current Issues

Flowchart to diagnose and resolve overload current protection issues.

Communication Error Diagnosis (E1)

Troubleshooting Unit Communication Errors

Steps to diagnose and fix communication errors between indoor and outdoor units.

Electrical Component Testing

DC Voltage Measurement Procedure

Reactor Resistance Measurement Procedure

Fan Speed Range Error (E3;F5) Diagnosis

Troubleshooting Fan Speed Malfunctions

Flowchart to diagnose and resolve indoor/outdoor fan speed problems.

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

Troubleshooting Sensor Circuit Faults

Steps to diagnose and fix temperature sensor circuit faults.

Refrigerant Leakage Detection (EC) Diagnosis

Troubleshooting Refrigerant Leakage

Flowchart to diagnose and resolve refrigerant leakage detection errors.

IPM Malfunction or Over-Current Protection (PO) Diagnosis

Troubleshooting IPM;IGBT Protection Issues

Steps to diagnose and resolve IPM or IGBT over-current protection faults.

Voltage Protection Errors (P1) Diagnosis

Troubleshooting Voltage Protection Issues

Flowchart to diagnose and resolve over/under voltage protection issues.

Compressor Top Temperature Protection (P2) Diagnosis

Troubleshooting Compressor Top Temperature Issues

Flowchart to diagnose and resolve compressor top high temperature protection.

Inverter Compressor Drive Error (P4) Diagnosis

Troubleshooting Inverter Compressor Drive Issues

Flowchart for diagnosing inverter compressor drive errors.

IPM Module Temperature Sensor Malfunction (P7) Diagnosis

Troubleshooting IPM Module Temperature Sensor Issues

Steps to diagnose and resolve IPM module temperature sensor faults.

Evaporator High Temperature Protection (J0) Malfunction

Troubleshooting J0 Malfunction

Flowchart for diagnosing and resolving evaporator high temperature protection (J0).

Condenser High Temperature Protection (J1) Malfunction

Troubleshooting J1 Malfunction

Flowchart for diagnosing and resolving high temperature condenser protection (J1).

Compressor Discharge Temperature Protection (J2) Malfunction

Troubleshooting J2 Malfunction

Flowchart for diagnosing compressor discharge temperature protection (J2).

PFC Module Protection (J3) Malfunction

Troubleshooting J3 Malfunction

Flowchart for diagnosing PFC module protection (J3) issues.

IPM Communication Error (J4) Malfunction

Troubleshooting J4 Malfunction

Flowchart for diagnosing communication errors between IPM and main control board (J4).

High Pressure Protection (J5) Malfunction

Troubleshooting J5 Malfunction

Flowchart for diagnosing high pressure protection (J5) issues.

Low Pressure Protection (J6;P6) Malfunction

Troubleshooting J6;P6 Malfunction

Flowchart for diagnosing low pressure protection (J6/P6) issues.

AC Power Input Voltage Protection (J8) Malfunction

Troubleshooting J8 Malfunction

Flowchart for diagnosing AC power input voltage protection (J8) issues.

Component Resistance Checks

Compressor and IPM Continuity Checks

Carrier 38MBRQ48A-3 Specifications

General

Brand	Carrier
Model	38MBRQ48A-3
Category	Heat Pump
Language	English