Mitsubishi Electric MUZ-GB50VA User Manual

SERVICE MANUAL
CONTENTS
1. TECHNICAL CHANGES ··································· 3
2. PART NAMES AND FUNCTIONS ····················· 4
3. SPECIFICATION ················································ 4
4. NOISE CRITERIA CURVES ······························ 6
5. OUTLINES AND DIMENSIONS ························ 6
6. WIRING DIAGRAM ············································ 7
7. REFRIGERANT SYSTEM DIAGRAM ··············· 9
8. PERFORMANCE CURVES ····························· 11
9. ACTUATOR CONTROL ··································· 16
10. SERVICE FUNCTIONS ···································· 17
11. TROUBLESHOOTING ····································· 18
12. DISASSEMBLY INSTRUCTIONS ···················· 44
13. RoHS PARTS LIST ·········································· 48
Models
MUZ-GB50VA -
E1
MUZ-GB50VA -
E2
MUZ-GB50VA -
E3
OUTDOOR UNIT
Indoor unit service manual
MSZ-GB·VA Series (OB454)
NOTE:
• This service manual describes technical data of the outdoor units.
HFC
utilized
R410A
Please void OB455 REVISED EDITION-F.
No. OB455
REVISED EDITION-G
Revision G:
• Errors in TROUBLESHOOTING have been
corrected.

Mitsubishi Electric MUZ-GB50VA Specifications

General

Type	Split System Air Conditioner
Brand	Mitsubishi Electric
Model	MUZ-GB50VA
Cooling Capacity	5.0 kW
Heating Capacity	6.0 kW
Refrigerant	R410A
Power Supply	220-240 V, 50 Hz
Energy Efficiency Ratio (EER)	3.21
Outdoor Unit Dimensions (W x H x D)	800 x 550 x 285 mm
Indoor Unit Weight	10 kg

Summary

1 TECHNICAL CHANGES

2 PART NAMES AND FUNCTIONS

3 SPECIFICATION

Specifications and rated conditions of main electric parts

Detailed specifications for main electrical components used in the outdoor unit.

4 NOISE CRITERIA CURVES

5 OUTLINES AND DIMENSIONS

6 WIRING DIAGRAM

7 REFRIGERANT SYSTEM DIAGRAM

MAX. REFRIGERANT PIPING LENGTH and MAX. HEIGHT DIFFERENCE

Specifies maximum refrigerant piping length and height difference limits.

ADDITIONAL REFRIGERANT CHARGE (R410A : g)

Details the additional refrigerant charge required for longer piping lengths.

8 PERFORMANCE CURVES

8-1. CAPACITY AND INPUT CURVES

Charts showing cooling capacity and input based on indoor/outdoor temperatures.

8-2. CAPACITY AND INPUT CORRECTION BY OPERATIONAL FREQUENCY OF COMPRESSOR

Corrections for capacity and input based on compressor operating frequency.

8-3. TEST RUN OPERATION

Procedure for performing a test run operation of the air conditioner.

8-4. OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT

Performance data related to outdoor low pressure and unit current in different modes.

9 ACTUATOR CONTROL

9-1. OUTDOOR FAN MOTOR CONTROL

Explains the operation and control logic of the outdoor fan motor.

9-2. R.V. COIL CONTROL

Details the control logic for the reversing valve (R.V.) coil in different modes.

9-3. RELATION BETWEEN MAIN SENSOR AND ACTUATOR

Shows the relationship between sensors and actuators for unit control.

10 SERVICE FUNCTIONS

10-1. CHANGE IN DEFROST SETTING

Instructions for changing the defrost finish temperature setting.

10-2. PRE-HEAT CONTROL SETTING

Configuration of the pre-heat control to prevent moisture interference.

11 TROUBLESHOOTING

11-1. CAUTIONS ON TROUBLESHOOTING

Important safety precautions and checks before troubleshooting the unit.

11-2. FAILURE MODE RECALL FUNCTION

Procedure to recall and identify past failure modes of the unit.

11-3. TROUBLESHOOTING CHECK TABLE

A table detailing symptoms, LED indications, conditions, and remedies for troubleshooting.

11-4. TROUBLE CRITERION OF MAIN PARTS

Criteria and methods for checking the normal operation of key components.

11-5. TROUBLESHOOTING FLOW

Step-by-step troubleshooting procedures for various unit issues.

11-6. TEST POINT DIAGRAM AND VOLTAGE

Diagrams and voltage measurements for diagnosing electronic control boards.

Electromagnetic Noise Issues

12 DISASSEMBLY INSTRUCTIONS

1. Removing the cabinet

Step-by-step guide to removing the external cabinet of the outdoor unit.

2. Removing the inverter assembly, inverter P.C. board and power board

Procedure for removing the inverter and power boards.

3. Removing the inverter assembly, inverter P.C. board

Steps to remove the inverter assembly and P.C. board for the E3 model.

4. Removing R.V. coil

Instructions for removing the reversing valve (R.V.) coil.

5. Removing the defrost thermistor, discharge temperature thermistor, outdoor heat exchanger temperature thermistor and ambient temperature thermistor

Guide to removing various thermistors from the unit.

6. Removing outdoor fan motor

Procedure for removing the outdoor fan motor assembly.

7. Removing the compressor and 4-way valve

Steps for removing the compressor and the 4-way valve.

8. Removing the reactor

Instructions for removing the reactor component.

13 RoHS PARTS LIST (RoHS compliant)

13-1. OUTDOOR UNIT STRUCTURAL PARTS, ELECTRICAL PARTS AND FUNCTIONAL PARTS

List of structural, electrical, and functional parts for MUZ-GB50VA-E1/E2 models.

13-2. OUTDOOR UNIT STRUCTURAL PARTS, ELECTRICAL PARTS AND FUNCTIONAL PARTS

List of structural, electrical, and functional parts for MUZ-GB50VA-E3 model.

13-3. ACCESSORY

List of accessories provided with the outdoor unit.