Mitsubishi Electric MS-18NN Series User Manual

SERVICE MANUAL
SPLIT-TYPE, AIR CONDITIONERS
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··············10
7. PERFORMANCE CURVES······························13
8. MICROPROCESSOR CONTROL ····················15
9. SERVICE FUNCTIONS ····································23
10. TROUBLESHOOTING······································24
11. DISASSEMBLY INSTRUCTIONS·····················30
12. PARTS LIST······················································34
13. OPTIONAL PARTS···········································38
Wireless type
Models
No. OB188
MS-18NN -
(
WH
)
· MU-18NN -
MS-24NN -
(
WH
)
· MU-24NN -
S1S1
S1S1
OB188--1.qxp 25/9/97 6:06 PM Page 3

Mitsubishi Electric MS-18NN Series Specifications

General

Refrigerant	R410A
Indoor Unit Dimensions (W x H x D)	Varies by model. Consult specific model documentation.
Outdoor Unit Dimensions (W x H x D)	Varies by model. Consult specific model documentation.
Type	Split System
Weight (Indoor Unit)	9.5 kg
Weight (Outdoor Unit)	32 kg
Cooling Capacity (kW)	1.8 kW
Heating Capacity (kW)	2.0 kW
Indoor Unit Weight	9.5 kg
Outdoor Unit Weight	32 kg

Summary

Technical Changes

Specifications

Outlines and Dimensions

Wiring Diagram

Indoor Unit Wiring Diagram

Wiring diagram for the indoor unit, detailing internal connections.

Outdoor Unit Wiring Diagram

Wiring diagram for the outdoor unit, detailing internal connections.

Refrigerant System Diagram

Refrigerant System Diagram for MS-18NN / MU-18NN

Illustrates the refrigerant flow for the 18NN model indoor and outdoor units.

Refrigerant System Diagram for MS-24NN / MU-24NN

Illustrates the refrigerant flow for the 24NN model indoor and outdoor units.

Microprocessor Control

I FEEL CONTROL Operation

Timer Operation

Emergency and Test Operation

Service Functions

Timer Short Mode for Service

PC Board Modification for Individual Operation

Troubleshooting

Troubleshooting Cautions and Procedures

Provides essential precautions and a general procedure for troubleshooting.

Troubleshooting Flowchart and Check Table

Flowchart and check table for diagnosing operational issues and symptoms.

Trouble Criterion of Main Parts

Lists resistance and voltage criteria for diagnosing main component faults.

Disassembly Instructions

Indoor Unit Disassembly

Outdoor Unit Disassembly