Mitsubishi Electric MUH-GA20VB-E1 - User Manual

CONTENTS
1. TECHNICAL CHANGES ····································2
2. PART NAMES AND FUNCTIONS······················3
3. SPECIFICATION·················································3
4. NOISE CRITERIA CURVES·······························5
5. OUTLINES AND DIMENSIONS ·························6
6. WIRING DIAGRAM ············································7
7. REFRIGERANT SYSTEM DIAGRAM················8
8. PERFORMANCE CURVES································9
9. ACTUATOR CONTROL····································19
10. SERVICE FUNCTIONS·····································20
11. TROUBLESHOOTING······································20
12. DISASSEMBLY INSTRUCTIONS·····················27
13. PARTS LIST······················································30
14. RoHS PARTS LIST···········································32
HFC
utilized
R410A
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS
MUH-GA20VB
MUH-GA25VB
MUH-GA35VB
Wireless type
Models
MUH-GA20VB-
MUH-GA20VB-
MUH-GA25VB-
MUH-GA25VB-
MUH-GA35VB-
MUH-GA35VB-
E3
E1
E2
E1
E2
E1
SERVICE MANUAL
OUTDOOR UNIT
Indoor unit service manual
MSC-GA• VB Series (OB385)
MSC-CA• VB Series (OB393)
MSC-CB• VB Series (OB439)
No. OB387
REVISED EDITION-B
Please void OB387 REVISED EDITION-A.
Revision B:
● MUH-GA35VB - has been added.
E3
NOTE:
• This service manual describes technical data of outdoor units.
• RoHS compliant products have <G> mark on the spec name plate.
For servicing of RoHS compliant products, refer to the RoHS Parts List.
OB387B-1.qxp 07.5.23 2:47 PM Page 1

Summary

Technical Changes

Specification

Wiring Diagram

Refrigerant System Diagram

Performance Curves

Actuator Control

Service Functions

Troubleshooting

Instruction of Troubleshooting

A step-by-step guide to diagnose and resolve operational issues based on error indicators.

Trouble Criterion of Main Parts

Lists key components and their resistance/voltage criteria for diagnosing faults.

Troubleshooting Flow

Flowchart for diagnosing issues with compressor and outdoor fan motor operation.

Compressor and;or Outdoor Fan Motor Doesnt Stop

Troubleshooting steps for when the compressor or fan fails to stop.

Unit Operates COOL Mode Even If Set to HEAT Mode

Diagnostic procedure for incorrect mode operation (COOL instead of HEAT).

Unit Operates HEAT Mode Even If Set to COOL Mode

Diagnostic procedure for incorrect mode operation (HEAT instead of COOL).

When Operation Indicator Lamp Flashes 0.5-Second Intervals. Outdoor Unit Does Not Operate

Guide to check mis-wiring and serial signal errors causing outdoor unit non-operation.

When Operation Indicator Lamp Flashes 6-Time. Thermistors in the Outdoor Unit Are Abnormal

Test Point Diagram and Voltage

Disassembly Instructions

Mitsubishi Electric MUH-GA20VB-E1 Specifications