Mitsubishi Electric MS-18NV User manual

SERVICE MANUAL
SPLIT-TYPE 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 ····································16
10. TROUBLESHOOTING······································18
11. DISASSEMBLY INSTRUCTIONS·····················24
12. PARTS LIST······················································28
13. OPTIONAL PARTS···········································31
Wireless type
Models
MS-18NV - (WH) · MU-18NV - E4E4
No. OB228
MS-18NV - E4

2
TECHNICAL CHANGES
MS-18NV - ➔MS-18NV -
1. Indoor electronic control P.C. board has changed.
MU-18NV - ➔MU-18NV -
1. Compressor has changed.(NH-33VMDT➔PH-33VPET)
2. Outdoor heat exchanger has changed.
3. Refrigerant filling capacity(R-22) has changed.(1.65kg➔1.05kg)
E4E3
E4E3
1
PART NAMES AND FUNCTIONS
2
INDOOR UNIT
Remote control
receiving section
Air cleaning filter(option)
Deodorizing filter(option)
Grille
(When the grille is open)
MS-18NV - E4

3
TEMPERATURE buttons
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
(TIME SET button)
VANE CONTROL button
OFF-TIMER button
RESET button
SWING buttons
MS-18NV - E4
OUTDOOR UNIT
MU-18NV - E4
REMOTE CONTROLLER

4
NOTE:Test conditions
Cooling : Indoor DB27:/ WB19:
Outdoor DB35:/ WB24:
SPECIFICATION
3
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:)
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"
MS-18NV - E4
Single phase, 220-240V, 50Hz
—
WHT-BLK183.8 BLK-RED250.5
1,015
320
190
850
605
290
14
5
4
10
10
Cooling
5.1
2.5
INDOOR 756 / OUTDOOR 2340-2400
15
9.1
1,910-2,010
95-92
51-55
8.46
INDOOR 0.25 / OUTDOOR 0.39
2.67-2.54
PH-33VPET
1,500
C-R1.08
C-S 2.18
RA4V27-EA or EF
RA6V50-OF or OG
WHT-BLK116.4 BLK-RED111
48
42
52
1,180
830-860
1
1.05
900 (MS32N1)

5
OUTLINES AND DIMENSIONS
4
MS-18NV - E4
MU-18NV - E4
OUTDOOR UNIT
INDOOR UNIT
3 297
450
450
352438
254
20
60
40
150 648 217
5190
995
19077550
320
1015
17.5
160
56
4holes 11o20 Indoor unit
Installation plate
Wireless remote controller
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.
Unit : mm

6
WIRING DIAGRAM
5
MU-18NV - E4
MODEL WIRING DIAGRAM
OUTDOOR UNIT
NOTE:1. Use copper conductors only.(For field wiring)
2. “w”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.
3. Symbols below indicate.
: Terminal block, : Connector
1.Slide the sleeve.
2.Pull the wire while
pushing the locking
lever.
SYMBOL
C1
C2
SYMBOL
F
MC
SYMBOL
MF
TB
NAME NAME NAME
COMPRESSOR CAPACITOR
OUTDOOR FAN CAPACITOR FUSE(2A)
COMPRESSOR(INNER THERMOSTAT)
OUTDOOR FAN MOTOR(INNER THEMOSTAT)
TERMINAL BLOCK
MS-18NV - E4 MODEL WIRING DIAGRAM
INDOOR UNIT
SYMBOL
RT12
TB
52C
SYMBOL
IC141
MF
MV
NR11
RT11
SYMBOL
C11
DSAR
F11
F12
HIC1
NAME NAME NAME
INDOOR FAN CAPACITOR
SURGE ABSORBER
FUSE(3.15A)
THERMAL FUSE(93¡C)
DC / DC CONVERTER
HYBRID IC
INDOOR FAN MOTOR
VANE MOTOR
VARISTOR
ROOM TEMPERATURE THERMISTOR
INDOOR COIL THERMISTOR
TERMINAL BLOCK
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
MF
BLK
WHT
RED
ORN
N
220-240V~
BLU 4
BLU
WHT
BLK
RED
C1
TB
WHT
ORN
F
C2 RED
WHT
1
2
3
GRN/YLW
FROM
INDOOR UNIT
CONNECTING
C
SR
MC
2w
w
CIRCUITBREAKER
50Hz
220-240V~
BRN
DSAR
GRN/YLW
LD1
REMOTE
CONTROLLER
3
1
DISPLAY
P.C.BOARD
101
CN 102
CN 151
CN ELECTRONIC CONTROL P.C BOARD
BLU
RECEIVER
P.C.BOARD
MV
5
F11
33
BLU
~/N 220-240V
CORD
POWER
SUPPLY
TO OUTDOOR
UNIT
CONNECTING
BRN
L
N
GRN/YLW
TB
52C
BRN
24
3
CN201
1
2
F12
WHT
BLU
BLU
BLU
TRANS
HIC1
111
CN
4
2
1
C11
CN211
BLK
WHT
GRY
RED
RT11
MF
3
121
CN
CN
112
NR11
IC141 RT12
YLW
BRN
w
w
w
w
w
w

7
REFRIGERANT SYSTEM DIAGRAM
6
MS-18NV - E4 MU-18NV - E4
INDOOR UNIT OUTDOOR UNIT
Indoor
heat
exchanger
Room temperature
thermistor
RT11
Refrigerant pipe [15.88
(Option)
(with heat insulator)
Flared
connection
Indoor coil
thermistor
RT12
Refrigerant pipe [6.35
(Option)
(with heat insulator)
Stop valve Capillary tube
[3.0X[2.0X700
Compressor
Accumulator
Stop valve
(with service port) Outdoor
heat
exchanger
Refrigerant flow in cooling
Strainer
Unit:mm
Distributor
Indoor
unit
w Max. Height
difference 5m
wHeight difference should be within 5m regardless of which unit,
indoor or outdoor position is high.
Outdoor unit
Refrigerant Piping
Max.length
A
Model Outdoor unit precharged
1050
Refrigerant piping length (one way)
15m
120
7m
0
10m
45
MS-18NV - E4
MAX. HEIGHT DIFFERENCE
ADDITIONAL REFRIGERANT CHARGE(R-22 : g)
Model Refrigerant piping
Max. length : m
A
Piping size O.D : mm Length of connecting pipe : m
Indoor unit
Gas 0.43
Liquid 0.5
Gas
15.88
Liquid
6.35
Outdoor unit
Gas 0
Liquid 0
MS-18NV - E4 15
MAX. REFRIGERANT PIPING LENGTH
Calculation : Xg=15g/mO(A-7)m

8
PERFORMANCE CURVES
Wet and dry-bulb
thermometers
Dry-bulb
thermometers
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
Indoor air wet-bulb temperature difference on the left side of the chart on next page shows the difference between the
indoor intake air wet-bulb temperature and the indoor outlet air wet-bulb temperature for your reference at service.
How to measure the indoor air wet-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 dry-bulb thermometers to the outdoor air inlet.
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 to start the EMERGENCY operation.
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.
7
INDOOR UNIT OUTDOOR UNIT
}
Cooling
MS-18NV - E4

9
MS-18NV - E4
11Both indoor and outdoor unit are under the same temperature/humidity condition.
OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT
COOL operation
22Air flow should be set at MAX.
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)
Dry-bulb temperature Relative humidity(%)
20 50
25 60
30 70
15 20
50 25 60 30 70(%) 35(:)
0.3
0.4
0.5
0.6
0.7
7
6
5
4
318 32
220V/240V
15 20
50 25 60 30 70(%) 35(:)
6
7
8
9
10
11
220V/240V
18 32
MU-18NV - E4 MU-18NV - E4
Ambient temperature(˚C)Ambient humidity(%) Ambient temperature(˚C)Ambient humidity(%)
Outdoor low pressure
(kgf/F•G)(MPa•G)
Outdoor unit current(A)

10
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) Select “I FEEL CONTROL”( ) mode with the
OPERATION SELECT button.
(3) The operation mode is determined by the room
temperature at start-up of the operation.
MICROPROCESSOR CONTROL
8
lighting
not lighting
About 2 : 
or more
Difference
betweeen set
temperature
and room
temperature
About 2 : 
or less
This shows that the
air conditioner is
operating to reach
the target temperature.
Please wait unitil 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
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, the 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.
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 mode of
“I FEEL CONTROL” that
determined by room
temperature at start-up
of the operation.
MS-18NV - E4
TEMPERATURE buttons
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
(TIME SET button)
VANE CONTROL button
OFF-TIMER button
RESET button
SWING buttons
Initial room temperature
25:or more
more than 13:,
less than 25:
mode
COOL mode of
“I FEEL CONTROL“
DRY mode of
“I FEEL CONTROL”
WIRELESS REMOTE CONTROLLER