Carrier 38MBRC Series - User Manual

Specifications subject to change without notice.
TABLE of CONTENTS
PAGE
SAFETY CONSIDERATIONS ....................................................... 1
INTRODUCTION............................................................................ 1
MODEL / SERIAL NUMBER NOMENCLATURES .................... 2
WIRING........................................................................................... 3
CONNECTION DIAGRAM............................................................ 4
WIRING DIAGRAMS..................................................................... 5
REFRIGERATION CYCLE DIAGRAM........................................ 7
REFRIGERANT LINES .................................................................. 8
SYSTEM EVACUATION AND CHARGING ............................... 9
SYSTEM VACUUM AND CHARGE ............................................ 9
ELECTRONIC FUNCTIONS ......................................................... 10
TROUBLESHOOTING................................................................... 15
DIAGNOSIS AND SOLUTION...................................................... 16
DIAGNOSIS AND SOLUTION...................................................... 18
DISASSEMBLY INSTRUCTIONS ................................................ 38
DISASSEMBLY INSTRUCTIONS ................................................ 42
APPENDICIES ................................................................................ 55
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 38MBRC 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
38MBRC
Outdoor Unit Single Zone Ductless System
Sizes 36 to 58

Carrier 38MBRC Series Specifications

General

Series	38MBRC
Type	Heat Pump
Cooling Capacity	18, 000 - 60, 000 BTU/h
HSPF Rating	Up to 9.5
Refrigerant	R-410A
Power Supply	208/230V

Summary

SAFETY CONSIDERATIONS

General Safety Guidelines

Outlines precautions for installation, startup, and servicing of HVAC equipment.

Safety Signal Words

Explains DANGER, WARNING, and CAUTION signal words used with safety alerts.

INTRODUCTION

Service Manual Purpose

Provides information for servicing, repairing, and maintaining the 38MBRC heat pumps.

MODEL; SERIAL NUMBER NOMENCLATURES

Unit Identification

Explains the model numbering system and unit size definitions.

WIRING

Wiring Specifications and Guidelines

Details recommended wiring methods, sizes, and precautions.

CONNECTION DIAGRAM

Unit Wiring Connections

Illustrates connection diagrams for indoor and outdoor units and terminals.

WIRING DIAGRAMS

Size 36 K Wiring Diagram and Codes

Provides the wiring diagram and component codes for the 36K model.

WIRING DIAGRAMS (CONT)

Sizes 48 K and 58 K Wiring Diagrams and Codes

Provides wiring diagrams and codes for 48K and 58K models.

REFRIGERATION CYCLE DIAGRAM

Refrigerant Flow Path

Illustrates the refrigerant cycle diagram showing component flow.

REFRIGERANT LINES

Line Sizing and Charging Guidelines

Provides guidelines for sizing lines, insulation, and refrigerant charge.

SYSTEM EVACUATION AND CHARGING

Vacuum and Evacuation Methods

Details deep and triple evacuation methods and vacuum pump usage.

ELECTRONIC FUNCTIONS

Sensor Definitions and Protections

Defines sensors and describes main protection functions like compressor restart delay and temperature limits.

Operation Modes

Explains FAN mode operation.

OPERATING MODES

Cooling and Heating Fan Rules

Rules for indoor and outdoor fan control in cooling and heating modes.

DEFROSTING MODE

Defrosting Conditions and Exit

Explains conditions triggering and terminating defrost mode.

ADDITIONAL FUNCTIONS

Evaporator Protection, Drying Mode, Auto-Restart

Covers evaporator protection, drying mode, and auto-restart features.

Auto Mode Operation

Describes how auto mode selects operating modes based on temperature.

ENQUIRY INFORMATION

Outdoor Unit Check Function Parameters

Details display values and meanings for outdoor unit check.

TROUBLESHOOTING

Diagnostic Procedures and Tools

Outlines recommended steps, required tools, and control board measurement notes.

DIAGNOSIS AND SOLUTION

Outdoor Unit Error Code Guide

Lists error codes, LED status, and pages for outdoor unit diagnostics.

OUTDOOR UNIT POINT CHECK FUNCTION

Check Function Parameter Interpretation

Explains display values and interpretation for outdoor unit checks.

COMMUNICATION ERROR DIAGNOSIS

EL 01 Troubleshooting

Describes communication errors and provides troubleshooting flowchart.

S COMMUNICATION TROUBLESHOOTING

Communication Fault Diagnosis

Provides a flowchart for diagnosing communication faults.

ELECTRICAL TESTS AND REMARKS

Multimeter Test Procedures

Instructions for testing DC voltage and reactor resistance.

FAN SPEED MALFUNCTION DIAGNOSIS

EC 07;EC 71;EC73 Troubleshooting

Describes fan speed issues and provides troubleshooting flowchart.

EEPROM PARAMETER ERROR DIAGNOSIS

EC 51 Troubleshooting

Describes EEPROM errors and provides troubleshooting steps.

LACK PHASE FAILURE DIAGNOSIS

EC 72 Troubleshooting

Describes lack phase failure and provides troubleshooting flowchart.

TEMPERATURE SENSOR DIAGNOSIS

EH;EC Sensor Issues Troubleshooting

Describes temperature sensor issues and provides troubleshooting flowchart.

IPM MALFUNCTION DIAGNOSIS

PC 00 Troubleshooting

Describes IPM malfunction and provides troubleshooting flowchart.

COMPRESSOR;IPM PROTECTION DIAGNOSIS

PC 02 Troubleshooting

Describes compressor/IPM protection and provides troubleshooting flowchart.

DISCHARGE TEMPERATURE PROTECTION DIAGNOSIS

PC 06 Troubleshooting

Describes discharge temp protection and provides troubleshooting flowchart.

CURRENT & SPEED ISSUE DIAGNOSIS

PC 08;PC 44;PC 46;PC 49 Troubleshooting

Describes current/speed issues and provides troubleshooting flowchart.

CONDENSER HIGH TEMPERATURE PROTECTION DIAGNOSIS

PC 0 A Troubleshooting

Describes condenser high temp protection and provides troubleshooting flowchart.

PFC MODULE PROTECTION DIAGNOSIS

PC 0 F Troubleshooting

Describes PFC module protection and provides troubleshooting flowchart.

VOLTAGE PROTECTION DIAGNOSIS

PC 01;PC 10;PC 11;PC 12 Troubleshooting

Describes voltage protection and provides troubleshooting flowchart.

HIGH PRESSURE PROTECTION DIAGNOSIS

PC 30 Troubleshooting

Describes high pressure protection and provides troubleshooting flowchart.

PCB-IPM COMMUNICATION ERROR DIAGNOSIS

PC 40 Troubleshooting

Describes PCB-IPM communication error and provides troubleshooting flowchart.

COMPRESSOR LACK PHASE PROTECTION DIAGNOSIS

PC 43 Troubleshooting

Describes compressor lack phase protection and provides troubleshooting flowchart.

IR CHIP DRIVE FAILURE DIAGNOSIS

PC 45 Troubleshooting

Describes IR chip failure and provides troubleshooting flowchart.

LOW AMBIENT TEMPERATURE PROTECTION

PC 0 L Description

Explains low ambient temperature protection.

PRESSURE ON SERVICE PORT

Cooling Pressure Charts

Presents pressure data tables and graphs for cooling mode.

PRESSURE ON SERVICE PORT (CONT.)

Heating Pressure Charts

Presents pressure data tables and graphs for heating mode.

DISASSEMBLY INSTRUCTIONS

Size 36 Unit Disassembly

Step-by-step instructions for disassembling the size 36 unit.

Sizes 48-58 Unit Disassembly

Step-by-step instructions for disassembling the size 48-58 unit.

Electrical Parts Disassembly

Instructions for disassembling electrical parts for 36K and 48K-58K models.

Fan Assembly and Motor Disassembly

Instructions for disassembling the fan assembly and motor.

Sound Blanket Removal

Instructions for removing the sound blanket.

4-Way Valve and Compressor Removal

Instructions for removing the 4-way valve and compressor.

APPENDICES

Appendix 1: Temperature Sensor Resistance Values

Table of resistance values for sensors T1, T2, T3, T4.

Appendix 2: Temperature Sensor Resistance Values

Table of resistance values for sensor T5.

Appendix 3: Temperature Conversion Table

Table for converting between Celsius and Fahrenheit.