Mitsubishi Electric MSH-18NV User manual

SERVICE MANUAL
SPLIT-TYPE, HEAT PUMP AIR CONDITIONERS
CONTENTS
1. TECHNICAL CHANGES ····································2
2. PART NAMES AND FUNCTIONS······················2
3. SPECIFICATION·················································4
4. OUTLINES AND DIMENSIONS ························ 5
5. WIRING DIAGRAM ············································6
6. REFRIGERANT SYSTEM DIAGRAM················7
7. PERFORMANCE CURVES································8
8. MICROPROCESSOR CONTROL ····················10
9. SERVICE FUNCTIONS ····································19
10. TROUBLESHOOTING······································21
11. DISASSEMBLY INSTRUCTIONS·····················30
12. PARTS LIST······················································34
13. OPTIONAL PARTS···········································37
Wireless type
Model
MSH-18NV - (WH) · MUH-18NV - E4E4
No. OB229
REVISED EDITION-A
MSH-18NV - E4
•Refer to the Service Manual OB185 REVISED EDITION C when MSH-18NV- is connected with
MXZ-32NV- or MXZ-32NV- as multi system units.
•Refer to the Service Manual OB227 REVISED EDITION-B when MSH-18NV- is connected with
MXZ-32RV- as multi system units.
E1
E4
E2E1
E4
Revision:
●Information for connecting MSH-18NV- with
MXZ-32RV- was described.
●TROUBLESHOOTING has been modified.
E1
E4

2
PART NAMES AND FUNCTIONS
2
INDOOR UNIT


,

(When the grille is open)
Front panel
MSH-18NV - E4
TECHNICAL CHANGES
MSH-18NV- became possible the connection to MXZ-32RV- as multi system units.
E1E4
1

3
Drainage hose
Piping
Air inlet
Air outlet
Drain outlet
(back and side)
OUTDOOR UNIT
MUH-18NV - E4
TEMPERATURE buttons
VANE CONTROL button
SWING button
OFF-TIMER button
RESET button
Signal transmitting section
Operation display section
OPERATE/STOP
(ON/OFF)button
OPERATION SELECT button
FAN SPEED CONTROL button
SLEEP button
ON-TIMER button
CLOCK SET button
HR. button
MIN. button
(TIMER SET button)
MSH-18NV - E4
REMOTE CONTROLLER

4
Capacity
Electrical data
Compressor
Indoor
fan motor
Outdoor
fan motor
Dimensions
Weight
Special remarks
Model
Function
Power supply
Coefficient of performance(C.O.P)
Capacity
Dehumidification
Air flow(Hi)
Power outlet
Running current
Power input
Auxiliary heater
Power factor
Starting current
Compressor motor current
Fan motor current
Model
Output
Winding resistance(at20:)
Model
Winding resistance(at20:)
Model
Winding resistance(at20:)
Indoor unit
Outdoor unit
Indoor unit
Outdoor unit
Air direction
Sound level
(Hi)
Fan speed
(Hi)
Fan speed
regulator
Refrigerant filling capacity(R-22)
Refrigerating oil (Model)
Thermistor
Width
Height
Depth
Width
Height
Depth
Indoor unit
Outdoor unit
Indoor unit
Outdoor unit
Indoor unit
Outdoor unit
RT11(at25:)
RT12(at25:)
RT61(at0:)
kW
R/h
K /h
A
A
W
A(kW)
%
A
A
A
W
"
"

"
mm
mm
mm
mm
mm
mm
kg
kg
dB
dB
rpm
rpm
kg
cc
k"
k"
k"
MSH-18NV - E4
Single phase,220-240V,50Hz
INDOOR 756 OUTDOOR 2142-2244
15
52-58
INDOOR 0.25 OUTDOOR 0.39
PH-36VPET
1600
C-R1.03 C-S2.04
RA4V27-EA or EF
WHT-BLK183.8 BLK-RED250.5
RA6V50-OF or OG
WHT-BLK116.4 BLK-RED111.0
1,015
320
190
850
605
290
14
54
5
42
52
1,180
810-845
4
1
1.65
900 (MS32N1)
10
10
33.18
Cooling
5.1
2.5
9.4-9.2
2,030-2,120
—
98-96
8.76-8.56
2.51-2.41
Heating
5.4
—
9.2-9.0
1,980-2,070
—
98-96
8.56-8.36
2.73-2.61
WMSH-18NV-
E4
(INDOOR UNIT)
Cooling Heating
Single phase,220-240V,50Hz
— —
—
756
10
0.28
60
—
97-89
—
—
0.25
—
—
—
—
RA4V27-EA or EF
WHT-BLK183.8 BLK-RED250.5
—
—
1,015
320
190
—
—
—
14
—
5
42
—
1,180
—
4
—
—
—
10
10
—
wRefer to the Service Manual OB185 REVISED EDITION C when MSH-18NV- is connected with
MXZ-32NV- or MXZ-32NV- as multi system units.
wRefer to the Service Manual OB227 REVISED EDITION-B when MSH-18NV- is connected with
MXZ-32RV- as multi system units.
E1
E4
E2E1
E4
SPECIFICATION
3
NOTE:Test conditions
Cooling : Indoor DB27°C / WB19°C Heating : Indoor DB20°C /WB15.5°C
Outdoor DB35°C / WB24°C Outdoor DB7°C / WB6°C

5
OUTLINES AND DIMENSIONS
4
Unit: mm
OUTDOOR UNIT
MSH-18NV - E4
MUH-18NV - E4
INDOOR UNIT
3 297
450
450
352438
254
20
60
40
150 648 217
5190
995
19077550
320
1015
17.5
160
56
4holes 11✕20 Indoor unit
Installation plate
Power supply cord
Lead to right 2m
Lead to left 1m
Wall hole [75
Installation plate
Liquid line [8-0.5m
Gas line [12-0.43m
Insulation [50 O.D
[28 I.D
Insulation [28
Drain hose [16
Air out
{
Air in
If the right/left sides or
back side is vacant, the
front has only to be 50cm
unobstructed.
If the front or right/left sides
are vacant, the top has only
to be 10cm unobstructed.
Drainage
3holes [33 Air out
Air in
Air in
Service panel
Liquid refrigerant
pipe joint
Refregerant pipe
(flared) [6.35
Gas refregerant
pipe joint
Refregerant pipe
(flared) [15.88
35-
30-
30
100
161
157
74
850
500
183
20 292
605 248
35
350
50
290
310 345
20
355
90
Drainage
hole [16.2

6
MSH-18NV - E4
MUH-18NV - E4
MODEL WIRING DIAGRAM
MODEL WIRING DIAGRAM
INDOOR UNIT
OUTDOOR UNIT
CIRCUIT BREAKER
N
2
12VDC L
50Hz
CORD
POWER
SUPPLY
~/N 220-240V
F11
NR11
TRANS
HIC1
12VDC
220-240V~
DSAR
BRN
GRN/YLW
LD1
DISPLAY
P.C.BOARD
RECEIVER
P.C.BOARD
33
101 102
CN CN
1
TO OUTDOOR
UNIT
CONNECTING
NBLU
GRN/YLW MV
151
CN
5
BLU 3
BLU
ELECTRONIC CONTROL P.C BOARD
REMOTE
CONTROLLER
3
BLU
BLU
RED 2
1
F12
2WHT
BRN
BRN
L
3
TB
CN201 CN211
121
CN
112
CN
3
4
RT11
BRN
YLW
RED
GRY
WHT
BLK
RT12
52C
IC141
C11
1
2
4MF
FOR MULTI SYSTEM
TO OUTDOOR
UNIT
CONNECTING
3
111
CN
❈
❈
❈❈
❈
❈
SYMBOL
RT12
TB
52C
SYMBOL
HIC1
MF
MV
NR11
RT11
SYMBOL
C11
DSAR
F11
F12
IC141
NAME NAME NAME
INDOOR FAN CAPACITOR
SURGE ABSORBER
FUSE(3.15A)
THERMAL FUSE(93:)
HYBRID IC
DC/DC CONVERTER
INDOOR FAN MOTOR(INNER FUSE)
VANE MOTOR
VARISTOR
ROOM TEMPERATURE THERMISTOR
INDOOR COIL THERMISTOR
TERMINAL BLOCK
CONTACTOR
CN720
52C
1
X62
21S4
CN721 MF
SR61
MC
WHT
WHT
WHT
VLT
VLT
COM
52C
TAB21
DSAR
ORN
WHT
WHT RED
RED
RED
WHT
BLU
BLU
RED
BLK
CN730
C65
DEICER P.C.BOARD
RT61
F61
IC881
X62
CN711
BLK
TRANS
TAB20
BLK
R
C
C1
FROM
INDOOR UNIT CONNECTING
GRN/YLW
12VDC TB
220-240V~
N
2
3
4
1
4
3
2
1
BLK
BLK
CN661
NO
NR61
S
3
2
❈
❈❈
❈
❈
NAME NAME NAME
SYMBOL
C1
C65
DSAR
F61
IC881
SYMBOL
TB
X62
21S4
52C
SYMBOL
MC
MF
NR61
RT61
SR61
COMPRESSOR CAPACITOR
OUTDOOR FAN CAPACITOR
SURGE ABSORBER
FUSE(2A)
DC/DC CONVERTER
COMPRESSOR(INNER THERMOSTAT)
OUTDOOR FAN MOTOR(INNER THERMOSTAT)
VARISTOR
DEFROST THERMISTOR
SOLID STATE RELAY
TERMINAL BLOCK
REVERSING VALVE COIL RELAY
REVERSING VALVE COIL
CONTACTOR
NOTE:1. For the outdoor electric wiring refer to the outdoor unit electric wiring diagram for servicing.
2. Use copper conductors only.(For field wiring)
3. Symbols below indicate.
: Terminal block, : Connector
WIRING DIAGRAM
5
Sleeve
Locking lever
NOTE:1. Use copper conductors only (For field wiring).
2. Symbols below indicate.
: Terminal block, : Connector
3. “❈”show the terminals with a lock mechanism, so they cannot be removed when you pull
the lead wire.
Be sure to pull the wire by pushing the locking lever (projected part) of the terminal with a finger.
1.Slide the sleeve.
2.Pull the wire while
pushing the locking
lever.

7
REFRIGERANT SYSTEM DIAGRAM
6
MSH-18NV - E4 MUH-18NV - E4
INDOOR UNIT OUTDOOR UNIT
Indoor
heat
exchanger
Room temperature
thermistor
RT11
Refrigerant pipe [15.88
(Option)
Flared connection
Flared connection
Indoor coil
thermistor
RT12
Refrigerant pipe[ 6.35
(Option)
Stop valve
Strainer
Check
valve
Capillary tube
[3.0o[2.0o500
Capillary tube
[3.0o[1.6o750
(2 pcs)
Compressor
Accumulator
Stop valve
(with service port)
Muffler
Outdoor
heat
exchanger
Defrost
thermistor
RT61
Reversing valve coil
(4-way valve coil)
Heating ON
Cooling OFF
Refrigerant flow in cooling
Refrigerant flow in heating
(with heat insulator)
Strainer
Distributor
Reversing valve
(4- way valve)
Model Piping size O.D : mm Length of connecting pipe : m
Refrigerant piping
Max. length : m
A
15
Indoor unit
Gas 0.43
Liquid 0.5
Gas
15.88
Liquid
6.35
Outdoor unit
Gas 0
Liquid 0
MSH-18NV - E4
Indoor
unit
wMax. Height
difference: 5m
A
Refrigerant Piping
Max. Length
wHeight difference should be within 5m
regardless of which unit, indoor or outdoor position is high.
Outdoor unit
Model
MSH-18NV - E4
Refrigerant piping length (one way)
Outdoor unit precharged
(up to 7m)
1650
15m
400
7m
010m
150
MAX. HEIGHT DIFFERENCE
ADDITIONAL REFRIGERANT CHARGE(R-22 : g)
MAX. REFRIGERANT PIPING LENGTH
Calculation : Xg=50g/m ✕ (A-7)m
(with heat insulator)

8
11.2
7.2
8.2
9.1
10.1
12.2
MSH-18NV - E4
7
The standard data contained in these specifications apply only to the operation of the air conditioner under normal conditions,
since operating conditions vary according to the areas where these units are installed. The following information has been
provided to clarify the operating characteristics of the air conditioner under the conditions indicated by the performance curve.
(1) GUARANTEED VOLTAGE
Rated voltage : ±10% (198 ~ 264V), 50Hz
(2) AIR FLOW
Air flow should be set at MAX.
(3) MAIN READINGS
(1) Indoor intake air wet-bulb temperature : °CWB
(2) Indoor outlet air wet-bulb temperature : °CWB
(3) Outdoor intake air dry-bulb temperature : °CDB
(4) Total input: W
(5) Indoor intake air dry-bulb temperature : °CDB
(6) Outdoor intake air wet-bulb temperature : °CWB
(7) Total input : W
Indoor air wet/dry-bulb temperature difference on the left side of the chart on this page and next page shows the
difference between the indoor intake air wet/dry-bulb temperature and the indoor outlet air wet/dry-bulb temperature for
your reference at service.
How to measure the indoor air wet-bulb/dry-bulb temperature difference
1. Attach at least 2 sets of wet-and dry-bulb thermometers to the indoor air intake as shown in the figure, and at least 2 sets
of wet-and dry-bulb thermometers to the indoor air outlet. The thermometers must be attached to the position where air
speed is high.
2. Attach at least 2 sets of wet-and dry-bulb thermometers to the outdoor air intake.
Cover the thermometers to prevent direct rays of the sun.
3. Check that the air filter is cleaned.
4. Open windows and doors of room.
5. Press the EMERGENCY OPERATION switch once(twice) to start the EMERGENCY COOL(HEAT) MODE.
6. When system stabilizes after more than 15 minutes, measure temperature and take an average temperature.
7. 10 minutes later, measure temperature again and check that the temperature does not change.
INDOOR UNIT OUTDOOR UNIT
}
}
Cooling
Heating
PERFORMANCE CURVES
Wet-and dry-bulb
thermometers Wet-and dry-bulb
thermometers
MSH-18NV - E4

9
28.0
25.9
23.7
21.6
19.4
17.2
15.1
12.9
MSH-18NV - E4
NOTE:The above curves are for the heating operation without any frost.
OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT
COOL operation
11Both indoor and outdoor unit are under the same temperature/humidity condition.
22Air flow should be set at MAX.
Dry-bulb temperature Relative humidity(%)
20 50
25 60
30 70
33The unit of pressure has been changed to MPa on the international system of units(SI unit system).
The conversion factor is : 1(MPa • G) =10.2(kgf/ff• G)
15 20
50 25 60 30 70(%) 35(:)
0.3
0.4
0.5
0.6
0.7
18 32
220V/240V
7
6
5
4
3
15 20
50 25 60 30 70(%) 35(:)
6
7
8
9
10
11
18 32
220V/240V
MUH-18NV - E4
MUH-18NV - E4
Outdoor low pressure
Ambient temperature(˚C)
Ambient humidity(%) Ambient temperature(˚C)
Ambient humidity(%)
Outdoor unit current (A)
(kgf/F•G)(MPa•G)
HEAT operation
Condition indoor:Dry bulb temperature 20.0°C
Wet bulb temperature 14.5°C
Outdoor:Dry bulb temperature 7,15,20°C
Wet bulb temperature 6,12,14.5°C
MUH-18NV - E4
5 10152025
7
8
9
10
11
721
220V/240V
(:)
Outdoor unit current (A)
Ambient temperature(˚C)

10
MICROPROCESSOR CONTROL
8
Once the operation mode are set, the same operation mode
can be repeated by simply turning the OPERATE/STOP
(ON/OFF) button ON.
Indoor unit receives the signal with a beep tone.
When the system turns off, 3-minute time delay will operate to
protect system from overload and compressor will not restart
for 3 minutes.
8-1. “I FEEL CONTROL” ( ) OPERATION
(1) Press OPERATE/STOP (ON/OFF) button on the remote
controller. Operation Indicator lamp of the indoor unit
turns on with a beep tone.
(2) Press OPERATION SELECT button to set “I FEEL
CONTROL”( ). Then a beep tone is heard.
(3) The operation mode is determined by the room
temperature at start-up of the operation.
lighting
not lighting
Approx. 2 : 
or more
Difference
betweeen set
temperature
and room
temperature
Approx. 2 : 
or less
This shows that the
air conditioner is
operating to reach
the target temperature.
Please wait unit the
target temperature is
obtained.
This shows that the
room temperature is
approaching the
target temperature.
Operation state
Indication
Operation Indicator
Operation Indicator lamp
The operation indicator at the right side of the indoor
unit indicates the operation state.
INDOOR UNIT DISPLAY SECTION
WIRELESS REMOTE CONTROLLER
Example
Previous operation
COOL mode of
“I FEEL CONTROL”
or COOL mode
• Once the mode is fixed, the mode does not change by
room temperature afterwards.
• Under the ON-TIMER ( ) operation, mode is
determined according to the room temperature as the
operation starts.
• When the system is stopped with the OPERATE/STOP
(ON/OFF) button on the remote controller, and restarted
within 2 hours in “I FEEL CONTROL” ( ) mode, the
system operates in previous mode automatically
regardless of the room temperature.
Mode
COOL mode of
"I FEEL CONTROL"
DRY mode of
"I FEEL CONTROL"
HEAT mode of
"I FEEL CONTROL"
Initial room temperature
25:or more
23:to 25:
less than 23:
Example
Previous operation
COOL mode of
“I FEEL CONTROL”
or COOL mode
When the system is restarted after 2 hours and more, the
operation mode is determined by the room temperature
at start-up of the operation.
Restart
COOL mode of
“I FEEL CONTROL”
Restart
COOL or DRY or
HEAT mode of “I FEEL
CONTROL” that
determined by room
temperature at start-up
of the operation.
MSH-18NV - E4