Mitsubishi Electric MSZ-HM18NA-U1 User Manual

Outdoor unit service manual
MUZ-HM•NA Series (OBH747)
NOTE:
RoHS compliant products have <G> mark on the spec name plate.
PARTS CATALOG (OBB746)
MSZ-HM24NA
INDOOR UNIT
SERVICE MANUAL
INDOOR UNIT
Models
MSZ-HM09NA
-
U1
MSZ-HM12NA
-
U1
MSZ-HM15NA
-
U1
MSZ-HM18NA
-
U1
MSZ-HM24NA
-
U1
CONTENTS
1. TECHNICAL CHANGES
·······································
2
2. PART NAMES AND FUNCTIONS ····················· 3
3. SPECIFICATION ················································ 5
4. OUTLINES AND DIMENSIONS ························ 7
5. WIRING DIAGRAM ············································ 8
6. REFRIGERANT SYSTEM DIAGRAM ··············· 9
7. SERVICE FUNCTIONS ··································· 10
8. MICROPROCESSOR CONTROL ··················· 12
9. TROUBLESHOOTING ····································· 16
10. DISASSEMBLY INSTRUCTIONS ···················· 30
No. OBH746
REVISED EDITION-B
Please void OBH746 REVISED EDITION-A.
Revision B:
• 3-1. OPERATING RANGE has been modified.

Mitsubishi Electric MSZ-HM18NA-U1 Specifications

General

Refrigerant	R410A
Voltage	208/230V
Cooling Capacity	18000 BTU/h
Outdoor Unit Noise Level	50 dB
Power Supply	1 Phase, 60 Hz

Summary

Unit Specifications and Performance Data

OPERATING RANGE

Details the operating temperature and humidity ranges for the unit.

Electrical Wiring Diagrams

Refrigerant System Diagrams

Service Functions and Procedures

Microprocessor Control and Operational Modes

WIRELESS REMOTE CONTROLLER

EMERGENCY/TEST OPERATION

Troubleshooting and Fault Diagnosis

CAUTIONS ON TROUBLESHOOTING

FAILURE MODE RECALL FUNCTION

Procedure to recall and check stored error codes from the unit.

Indoor unit failure mode table

Table listing specific failure modes based on indicator lamp patterns.

INSTRUCTION OF TROUBLESHOOTING

Flowchart to guide troubleshooting based on unit operation status.

TROUBLESHOOTING CHECK TABLE

Detailed table correlating symptoms, conditions, and remedies for abnormalities.

TROUBLE CRITERION OF MAIN PARTS

Troubleshooting Flowcharts

Step-by-step troubleshooting flow for specific faults like fan motor issues.

Remote Controller & Indoor PC Board Check

Procedures to check the remote controller and the indoor electronic control board.

Indoor PC Board & Fan Motor Check

Steps to diagnose issues with the indoor PC board and fan motor.

Miswiring and Serial Signal Error Check

Guidance for identifying and correcting wiring and communication errors.

Test Point Diagrams and Voltage Readings

Diagrams showing test points and expected voltage readings for diagnostics.

Disassembly Instructions and Procedures