Mitsubishi Electric MSC-A12YV-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. MICROPROCESSOR CONTROL ······················9
9. SERVICE FUNCTIONS ····································17
10. TROUBLESHOOTING······································19
11. DISASSEMBLY INSTRUCTIONS·····················26
12. PARTS LIST······················································28
Wireless type
Models
MSC-A07YV -
(WH)
MSC-A09YV -
(WH)
MSC-A12YV -
(WH)
E1
E1
E1
MSC-A07YV -
MSC-A09YV -
MSC-A12YV -
E1
E1
E1
No. OB329
HFC
utilized
R410A
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-A07/A09/A12YV - , refer to the service manual OB330.
•As for outdoor units MUH-A07/A09/A12YV - , refer to the service manual OB331.
•As for outdoor units MUX-A10/A19/A20/A25/A26WV - , refer to the service manual OB307 REVISED
EDITION-A.
•As for outdoor units MUX-A22WV - , refer to the service manual OB318.
•As for outdoor units MXZ-A18/A26/A32WV - , refer to the service manual OB319.
E1
E1
E1
E1
E1
OB329-1.qxp 03.12.3 1:16 PM Page 1

Summary

Specifications

Microprocessor Control

Thermostat Control

Explains how thermostat functions based on temperature differences.

Dry Operation Mode

Explains the operation and control logic for the dry mode.

Heat Operation Mode

Details the control and functions specific to the heating mode.

I Feel Control Operation

Timer Operation

Emergency Test Operation

Service Functions

Auto Restart Function

Troubleshooting

Troubleshooting Procedure

Instruction of Troubleshooting

Provides a detailed flowchart for troubleshooting common issues.

Troubleshooting Check Table

A table correlating operation indicator patterns with specific faults.

Trouble Criterion of Main Parts

Mis-wiring and Serial Signal Error Check

Procedure to diagnose wiring issues and serial communication errors.

Test Point Diagram and Voltage

Disassembly Instructions

Parts List

Mitsubishi Electric MSC-A12YV-E1 Specifications

General

Cooling Capacity	3.5 kW
Heating Capacity	4.0 kW
Power Supply	220-240 V, 50 Hz
Type	Air Conditioner
Indoor Unit Noise Level	21 dB