Mitsubishi Electric MSC-GA20VB- E1 User Manual

SERVICE MANUAL
CONTENTS
1. TECHNICAL CHANGES ····································3
2. PART NAMES AND FUNCTIONS······················3
3. SPECIFICATION·················································5
4. NOISE CRITERIA CURVES·······························6
5. OUTLINES AND DIMENSIONS ·························7
6. WIRING DIAGRAM ············································8
7. REFRIGERANT SYSTEM DIAGRAM················8
8. SERVICE FUNCTIONS ······································9
9. TROUBLESHOOTING······································11
10. DISASSEMBLY INSTRUCTIONS·····················18
11. PARTS LIST······················································20
12. OPTIONAL PARTS···········································22
Wireless type
Models
MSC-GA20VB -
(WH)
MSC-GA25VB -
(WH)
MSC-GA35VB -
(WH)
E1
E1
E1
MSC-GA20VB -
MSC-GA25VB -
MSC-GA35VB -
E1
E1
E1
No. OB385
SPLIT-TYPE, AIR CONDITIONERS
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS
Indication of model name
NOTE:
•This manual describes technical data of indoor units.
•As for outdoor units MU-GA20/GA25/GA35VB - , refer to the service manual OB386.
•As for outdoor units MUH-GA20/GA25/GA35VB - , refer to the service manual OB387.
•As for outdoor units MUX-2A28/2A59/3A60/3A63/2A70/4A73VB - , refer to the service manual
OB384.
•As for outdoor units MXZ-A14/A18/A26/A32WV - , refer to the service manual OB319 REVISED
EDITION-A.
E1
E1
E1
E1
OB385-1.qxp 05.1.25 18:50 Page 1

Mitsubishi Electric MSC-GA20VB- E1 Specifications

General

Brand	Mitsubishi Electric
Model	MSC-GA20VB- E1
Category	Air Conditioner
Language	English

Summary

2 PART NAMES AND FUNCTIONS

3 SPECIFICATION

Technical Specifications Overview

Presents detailed technical specifications for cooling and heating modes, electrical data, and special remarks.

4 NOISE CRITERIA CURVES

Sound Pressure Level Graphs

5 OUTLINES AND DIMENSIONS

Unit Physical Dimensions and Layout

6 WIRING DIAGRAM

Indoor Unit Electrical Schematics

Details the internal wiring diagram for the indoor unit, including component symbols and terminal blocks.

7 REFRIGERANT SYSTEM DIAGRAM

Refrigerant Circuitry Overview

Depicts the refrigerant flow path and main components like the indoor coil and thermistors.

8 SERVICE FUNCTIONS

9 TROUBLESHOOTING

Troubleshooting Precautions and General Steps

Troubleshooting Flowcharts for Common Issues

Presents flowcharts for diagnosing common problems like outdoor unit non-operation or abnormal indicator flashes.

Troubleshooting Symptom and Checkpoint Table

A detailed table correlating operation indicator symptoms with potential causes and checkpoints for diagnosis.

Main Component Diagnostic Criteria

Details methods and criteria for checking critical components like thermistors, fan motors, and vane motors.

Indoor Fan Motor Fault Diagnosis

Provides a step-by-step troubleshooting guide specifically for indoor fan motor operation issues.

Remote Controller and Receiver Malfunction Checks

Indoor Electronic Control Board Diagnosis

Mis-wiring and Serial Signal Error Troubleshooting

Electrical Test Points and Voltage References

10 DISASSEMBLY INSTRUCTIONS

Front Panel and Electronic Board Removal

11 PARTS LIST

Indoor Unit Structural Component List

Electrical and Functional Component Catalog

Details electrical components such as motors, thermistors, fuses, varistors, and boards with their part numbers.

Heat Exchanger Assembly Parts