Mitsubishi Electric MUH-09NV User Manual

SERVICE MANUAL
SPLIT-TYPE,HEAT PUMP AIR CONDITIONERS
CONTENTS
1. TECHNICAL CHANGES ····································2
2. PART NAMES AND FUNCTIONS······················3
3. SPECIFICATION·················································6
4. OUTLINES AND DIMENSIONS ······················ 11
5. WIRING DIAGRAM ··········································15
6. REFRIGERANT SYSTEM DIAGRAM··············24
7. PERFORMANCE CURVES······························29
8. MICROPROCESSOR CONTROL ····················33
9. SERVICE FUNCTIONS ····································44
10. TROUBLESHOOTING······································47
11. DISASSEMBLY INSTRUCTIONS·····················60
12. PARTS LIST······················································70
13. OPTIONAL PARTS ····································BACK
Wireless type
Models
MSH-07NV -
(
WH
)
· MUH-07NV -
MSH-09NV -
(
WH
)
· MUH-09NV -
MSH-12NV -
(
WH
)
· MUH-12NV -
MSH-18NV -
(
WH
)
· MUH-18NV -
MSH-24NV -
(
WH
)
· MUH-24NV -
MSH-07NV -
(
WH
)
· MUH-07NV -
MSH-09NV -
(
WH
)
· MUH-09NV -
MSH-12NV -
(
WH
)
· MUH-12NV -
MSH-18NV -
(
WH
)
· MUH-18NV -
MSH-24NV -
(
WH
)
· MUH-24NV -
MSH-18NV -
(
WH
)
· MUH-18NV -
E3E3
E2E2
E2E2
E2E2
E2E2
E2E2
E1E1
E1E1
E1E1
E1E1
E1E1
No. OB207
MSH-18NV -
MSH-18NV -
MSH-18NV -
E3
E2
E1
This Servise Manual OB207 deals with MSH-07/09/12/18/24NV-E1,
MUH-07/09/12/18/24NV-E1, MSH-18NV-E2, and MUH-18NV-E2 in
OB176 REVISED EDITION-A issued in July in1997.
Therefore, please refer to OB207, not to OB176 REVISED
EDITION-A, for the above models.
Refer to the Service Manual OB185 when MSH-07/09/12NV- , MSH-07/09/12/18NV- , and MSH-18NV-
are connected with MXZ-32NV- as multi system units.
E1
E3E2E1
OB207t-1qxp 25/9/97 8:51 PM Page 1

Mitsubishi Electric MUH-09NV Specifications

General

Brand	Mitsubishi Electric
Model	MUH-09NV
Category	Air Conditioner
Language	English

Summary

1 TECHNICAL CHANGES

2 PART NAMES AND FUNCTIONS

REMOTE CONTROLLER

3 SPECIFICATION

4 OUTLINES AND DIMENSIONS

5 WIRING DIAGRAM

6 REFRIGERANT SYSTEM DIAGRAM

MAX. REFRIGERANT PIPING LENGTH

EVACUATION PROCEDURES(AIR PURGE)

7 PERFORMANCE CURVES

OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT

8 MICROPROCESSOR CONTROL

8-1. "I FEEL CONTROL" (□) OPERATION

Explains the "I FEEL CONTROL" mode and its behavior based on room temperature.

(5) TEMPERATURES buttons

Describes the function of temperature adjustment buttons and fuzzy control.

COOL mode of "I FEEL CONTROL"

DRY mode of "I FEEL CONTROL"

HEAT mode of "I FEEL CONTROL"

2. High pressure protection

3. Defrostings

(3) Defrosting time chart

Illustrates the timing of components during the defrosting cycle.

4. Reversing valve control

8-2. COOL OPERATION

8-3. DRY OPERATION

8-4. HEAT OPERATION

8-5. FAN MOTOR CONTROL

8-6. AUTO VANE OPERATION

(4) VANE AUTO mode

Explains automatic vane angle determination for optimal air distribution.

(7) Cold air prevention in HEAT operation

Details how cold air is prevented during heating operation.

8-8. TIMER OPERATION

8-9. EMERGENCY-TEST OPERATION

9 SERVICE FUNCTIONS

1. COMPULSORY DEFROSTING MODE FOR SERVICE

Describes forcing defrost mode for servicing.

2. DEFROST TERMINATION CHANGE

Explains altering defrost interval and temperature settings.

4. P.C. BOARD MODIFICATION FOR INDIVIDUAL OPERATION

Explains modifications for individual unit control with multiple remotes.

10 TROUBLESHOOTING

10-1 Cautions on troubleshooting

Lists important precautions and checks before troubleshooting.

10-1-3 Troubleshooting procedure

Describes diagnosing issues based on indicator lamps.

10-1-4 How to replace batteries

Guides on remote battery replacement and reset.

10-2 Instruction of troubleshooting

10-2-1 troubleshooting check table

10-2-2 Trouble criterion of main parts

A Check of indoor fan motor

B Check of receiver P.C. board

C Check of indoor electronic control P.C. board

D Check of outdoor unit

E How to check mis-wiring and serial signal error (when outdoor unit does not work)

TEST POINT DIAGRAM AND VOLTAGE

Outdoor deicer P.C. board

11 DISASSEMBLY INSTRUCTIONS

11-1 MSH-07NV / MSH-09NV / MSH-12NV INDOOR UNIT

Specific disassembly steps for the indoor units of MSH-07/09/12 series.

11-2 MSH-18NV / MSH-24NV INDOOR UNIT

Disassembly instructions for MSH-18/24 indoor units.

11-3 MUH-07NV / MUH-09NV OUTDOOR UNIT

Steps for disassembling MUH-07/09 outdoor units.

11-4 MUH-12NV / MUH-18NV OUTDOOR UNIT

Disassembly instructions for MUH-12/18 outdoor units.

11-5 MUH-24NV OUTDOOR UNIT

Disassembly procedure for MUH-24 outdoor units.

12 PARTS LIST

13 OPTIONAL PARTS

1. REFRIGERANT PIPES

Details optional refrigerant pipe kits, including lengths and sizes.

2. AIR CLEANING FILTER

Describes the air cleaning filter and its maintenance.

3. DEODORIZING FILTER

Explains the deodorizing filter and its cleaning/replacement.