Mitsubishi Electric MUZ-FH18NA User Manual

SERVICE MANUAL
CONTENTS
1. TECHNICAL CHANGES ··································· 2
2. PART NAMES AND FUNCTIONS ····················· 3
3. SPECIFICATION ················································ 4
4. OUTLINES AND DIMENSIONS ························ 6
5. WIRING DIAGRAM ············································ 8
6. REFRIGERANT SYSTEM DIAGRAM ··············11
7. DATA ································································ 13
8. ACTUATOR CONTROL ··································· 21
9. SERVICE FUNCTIONS ··································· 22
10. TROUBLESHOOTING ····································· 23
11. DISASSEMBLY INSTRUCTIONS ···················· 44
Models
SPLIT-TYPE AIR CONDITIONERS
OUTDOOR UNIT
Indoor unit service manual
MSZ-FH•NA Series (OBH683)
NOTE:
RoHS compliant products have <G> mark on the spec name plate.
HFC
utilized
R410A
No. OBH684
REVISED EDITION-B
PARTS CATALOG (OBB684)
MUZ-FH09NA
MUZ-FH12NA
MUZ-FH09NAH
MUZ-FH12NAH
Please void OBH684 REVISED EDITION-A.
Revision B:
• MUZ-FH18NA and MUZ-FH18NAH have been
added.
MUZ-FH09NA
MUZ-FH12NA
MUZ-FH15NA
MUZ-FH18NA
MUZ-FH09NAH
MUZ-FH12NAH
MUZ-FH15NAH
MUZ-FH18NAH

Mitsubishi Electric MUZ-FH18NA Specifications

General

Cooling Capacity	18, 000 BTU/h
Heating Capacity	21, 600 BTU/h
Seasonal Energy Efficiency Ratio (SEER)	20.5
Refrigerant	R410A
Type	Heat Pump
Indoor Noise Level	19 dB (Low)
Outdoor Noise Level	49 dB
Power Supply	208/230V, 1Ph, 60Hz
Operating Temperature (Cooling)	14° to 115°F
Operating Temperature (Heating)	-13° to 70°F

Summary

Technical Changes

Part Names and Functions

Specification

Outlines and Dimensions

Wiring Diagram

Refrigerant System Diagram

Maximum Refrigerant Piping Length and Height Difference

Additional Refrigerant Charge

Data

Performance Data

Detailed performance data including cooling capacity and corrections.

Heating Capacity

Data related to heating capacity under various conditions.

Performance Curve

Condensing Pressure

Standard Operation Data

Troubleshooting

Cautions on Troubleshooting

Important safety and procedural notes before starting troubleshooting.

Failure Mode Recall Function

Procedure to recall and diagnose past system failures.

Troubleshooting Check Table

Table listing symptoms, LED indications, conditions, and remedies for faults.

Trouble Criterion of Main Parts

Criteria for checking the normal operation of key components.

Troubleshooting Flow

Step-by-step diagnostic guides for various system issues.

Disassembly Instructions

Removing the cabinet

Steps to remove the outer cabinet and its panels for access.

Removing the inverter assembly, P.C. board

Procedure for disassembling the inverter and associated electronic boards.

Removing R.V. coil

Instructions for removing the reversing valve coil.

Removing outdoor fan motor

Steps to safely remove the outdoor fan motor.

Removing the compressor and 4-way valve

Procedure for detaching the compressor and 4-way valve.