Mitsubishi Electric MU-A12WV User Manual

SERVICE MANUAL
CONTENTS
1. TECHNICAL CHANGES ····································2
2. PART NAMES AND FUNCTIONS······················6
3. INDOOR/OUTDOOR
CORRESPONDENCE TABLE ···························8
4. INDOOR UNITS COMBINATION ·······················9
5. SPECIFICATION···············································10
6. NOISE CRITERIA CURVES···························· 17
7. OUTLINES AND DIMENSIONS ······················ 20
8. WIRING DIAGRAM ··········································25
9. REFRIGERANT SYSTEM DIAGRAM··············32
10. PERFORMANCE CURVES······························45
11. MICROPROCESSOR CONTROL·····················84
12. SERVICE FUNCTIONS···································102
13. TROUBLESHOOTING····································104
14. DISASSEMBLY INSTRUCTIONS···················129
15. PARTS LIST····················································144
16. OPTIONAL PARTS·········································157
Wireless type
Models
MSC-A07WV -
(
WH
)
· MU-A07WV -
MSC-A09WV -
(
WH
)
· MU-A09WV -
MSC-A12WV -
(
WH
)
· MU-A12WV -
MSC-A07WV -
(
WH
)
· MUH-A07WV -
MSC-A09WV -
(
WH
)
· MUH-A09WV -
MSC-A12WV -
(
WH
)
· MUH-A12WV -
Multi system type
Models
MSC-A07WV -
(
WH
)
· MUX-A10WV -
MSC-A09WV -
(
WH
)
· MUX-A19WV -
MSC-A12WV -
(
WH
)
· MUX-A20WV -
· MUX-A25WV -
· MUX-A26WV -
Inverter-controlled multi system Model
· MXZ-A18WV -
E1
E1
E1
E1E1
E1E1
E1E1
E1E1
E1E1
E1E1
E1E1
E1E1
E1E1
MSC-A07WV -
MSC-A09WV -
MSC-A12WV -
E1
E1
E1
No. OB307
REVISED EDITION-A
HFC
utilized
R410A
SPLIT-TYPE, AIR CONDITIONERS
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS
Revision:
● MXZ-A18WV - have been added.
● MSC-A07/09/12WV - Part No.
.
have changed.
VARISTOR (NR11& NR12)
E02 336 385 ➔ E02 749 385
● Please void OB307.
E1
E1
Indication of
model name
Remote
controller
OB307A1.qxp 03.2.19 3:56 PM Page 1
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Mitsubishi Electric MU-A12WV Specifications

General

Brand	Mitsubishi Electric
Model	MU-A12WV
Category	Air Conditioner
Language	English

Summary

Technical Changes

Part Names and Functions

Indoor Unit

Details of indoor unit components and their functions.

Outdoor Unit

Details of outdoor unit components and their functions.

Indoor/Outdoor Correspondence Table

Indoor Units Combination

Specification

Noise Criteria Curves

Outlines and Dimensions

Indoor Unit

Physical dimensions and installation details for indoor units.

Outdoor Unit

Physical dimensions and installation details for outdoor units.

Wiring Diagram

Refrigerant System Diagram

MSC-A07WV - MU-A07WV -

Refrigerant circuit diagram for specific models.

MSC-A12WV - MU-A12WV -

Refrigerant circuit diagram for specific models.

Performance Curves

Capacity and Input Curves

Graphs showing capacity and input based on operating conditions.

Microprocessor Control

Wireless Remote Controller

Details on remote controller functions and display.

Indoor Unit Display Section

Explanation of the operation indicator lamp and its states.

Service Functions

12-1. Compulsory Defrosting Mode for Service

Procedure for forcing defrost mode for servicing purposes.

12-2. Change in Defrost Setting

How to change defrost interval time and start/finish temperatures.

12-4. P.C. Board Modification for Individual Operation

Modifying P.C. boards for individual indoor unit operation.

Troubleshooting

13-1. Cautions on Troubleshooting

Important warnings and precautions before starting troubleshooting.

Troubleshooting Procedure

Step-by-step guide to diagnose and resolve issues.

How to Replace Batteries

Instructions for replacing remote controller batteries.

Disassembly Instructions

14-1. Indoor Unit

Step-by-step instructions for disassembling the indoor unit.

14-2. Outdoor Unit

Disassembly steps for the outdoor unit.

14-3. MUH Outdoor Unit

Disassembly steps for MUH outdoor units.

14-5. MUX Outdoor Unit

Disassembly steps for MUX outdoor units.

14-6. MXZ-A18WV Outdoor Unit

Disassembly steps for the MXZ-A18WV outdoor unit.

Parts List

15-1. Indoor Unit Structural Parts

List of structural components for indoor units with part numbers.

15-3. Indoor Unit Electrical Parts and Functional Parts

Electrical components and functional parts for indoor units.

15-5. Outdoor Unit Structural Parts

List of structural components for outdoor units with part numbers.

15-6. Outdoor Unit Electrical Parts and Functional Parts

Electrical components and functional parts for outdoor units.

15-8. Outdoor Unit Electrical Parts and Functional Parts

Electrical and functional parts for MUH outdoor units.

15-10. Outdoor Unit Structural Parts

Structural components for MUX outdoor units.

15-14. Outdoor Unit Functional Parts and Electrical Parts

Electrical and functional parts for MXZ-A18WV.

Optional Parts

16-1. Different-Diameter Pipe

Specifications for different diameter pipes used in installations.