Mitsubishi Electric MSZ-A12YV-E1WH User Manual

SERVICE MANUAL
CONTENTS
1. PART NAMES AND FUNCTIONS······················2
2. SPECIFICATION·················································4
3. NOISE CRITERIA CURVES·······························5
4. OUTLINES AND DIMENSIONS ·························6
5. WIRING DIAGRAM ············································7
6. REFRIGERANT SYSTEM DIAGRAM················7
7. SERVICE FUNCTIONS ······································8
8. TROUBLESHOOTING······································10
9. DISASSEMBLY INSTRUCTIONS ····················19
10. PARTS LIST······················································21
11. OPTIONAL PARTS···········································23
Wireless type
Models
MSZ-A09YV -
(WH)
MSZ-A12YV -
(WH)
E1
E1
No. OB327
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS
Indication of model name
MSZ-A09YV -
MSZ-A12YV -
E1
E1
NOTE:
This service manual describes technical data of the indoor units.
•Refer to the service manual OB328 when MSZ-A09YV- or MSZ-A12YV- is connected
with MUZ-A09YV- , MUZ-A12YV- , MUZ-A09YVH- or MUZ-A12YVH- .
•Refer to the service manual OB319 when MSZ-A09YV- or MSZ-A12YV- is connected
with MXZ-A18WV- , MXZ-A26WV- or MXZ-A32WV- as multi system units.
E1E1E1
E1E1
E1E1E1E1
E1E1
OB327 --1qxp 04.1.8 1:41 PM Page 1

Mitsubishi Electric MSZ-A12YV-E1WH Specifications

General

Cooling Capacity	3.5 kW
Heating Capacity	4.0 kW
Refrigerant	R32
Power Supply	220-240 V / 50 Hz
Outdoor Unit Noise Level	50 dB

Summary

PART NAMES AND FUNCTIONS

Indoor Unit Components Overview

SPECIFICATIONS

WIRING AND REFRIGERANT DIAGRAMS

Indoor Unit Wiring Diagram

Indoor Unit Refrigerant System Diagram

SERVICE FUNCTIONS

Timer Short Mode Configuration

Explains how to shorten timer settings for service purposes.

PC Board Modification for Individual Operation

Details PC board modifications for multi-unit remote control.

Auto Restart Function Operation

Describes the unit's behavior after a power failure.

Releasing Auto Restart Function

TROUBLESHOOTING BASICS

Troubleshooting Safety Precautions

Essential safety guidelines to follow before troubleshooting.

General Troubleshooting Procedure

Step-by-step guide for diagnosing unit issues.

Remote Controller Battery Replacement

Instructions for replacing batteries in the remote controller.

HORIZONTAL VANE INSTALLATION

Vane Installation Procedure

Procedure to verify correct installation of horizontal vanes.

DETAILED TROUBLESHOOTING GUIDE

Troubleshooting Scenarios and Causes

Covers various operational failures and their potential causes.

TROUBLESHOOTING CHECK TABLE

Symptom Detection and Check Points

A table linking symptoms to detection methods and check points.

MAIN PARTS TROUBLE CRITERIA

Sensor and Motor Component Checks

Criteria for checking thermistors, fan motor, and vane motor resistance/voltage.

Indoor Fan Motor Specific Troubleshooting

Detailed steps for diagnosing indoor fan motor issues.

COMPONENT-SPECIFIC TROUBLESHOOTING

Remote Controller and Receiver Board Check

Steps to diagnose issues with the remote controller and receiver.

Indoor Electronic Control PC Board Check

MIS-WIRING CHECK PROCEDURE

Mis-wiring Detection and Verification

SPECIFIC COMPONENT CHECKS

Horizontal Vane and Safety Device Check

Thermal Fuse Resistance Check

TEST POINT DIAGRAMS AND VOLTAGES

PC Board Test Points and Voltage Readings

Auto Restart Function Release Procedure

DISASSEMBLY INSTRUCTIONS

Indoor Unit Disassembly Overview

Panel and PC Board Removal Steps

ELECTRICAL BOX AND NOZZLE ASSEMBLY REMOVAL

Electrical Box and Nozzle Assembly Removal

Fan Motor and Line Flow Fan Removal