Mitsubishi MCFH-24NV-EB, MUCFH-24NV-EB Service Manual
(When installed on the ceiling)
(When installed on the floor)
Note:
●Refer to OB196 REVISED EDITION-A for the details of
MCFH-24NV- and MUCFH-24NV- .
FLOOR AND CEILING TYPE AIR CONDITIONERS
SERVICE MANUAL
Wireless type
Models
EAEA
No. OB266
MCFH-24NV-
(WH)
·MUCFH-24NV-
CONTENTS
1. TECHNICAL CHANGES ····································2
2. PART NAMES AND FUNCTIONS······················2
3. SPECIFICATION·················································4
4. OUTLINES AND DIMENSIONS·························5
5. WIRING DIAGRAM ············································7
6. REFRIGERANT SYSTEM DIAGRAM················8
7. PERFORMANCE CURVES································9
8. MICROPROCESSOR CONTROL ····················11
9. SERVICE FUNCTIONS ····································21
10. TROUBLESHOOTING ······································23
11. DISASSEMBLY INSTRUCTIONS·····················34
12. PARTS LIST······················································38
13. OPTIONAL PARTS ···········································42
EBEB
1
(When installed on the floor)
(When the air inlet grille is opened.)
Deodorizing filter (gray sponge type)(option)
Air filter
Remote controller
Air inlet
Operation section
Air cleaning filter (whilte bellows type)(option)
Front panel
Receiving section
Operation indicator lamp
Horizontal vane
Vertical vanes
Emergency operation switch
(When installed on the ceiling)
ACCESSORIES
Item
Installation plate
Unit fixing screw 5 o 12mm
Wireless remote controller
Remote controller mounting hardware
Fixing screw for 3.5 o 16mm (Black)
Battery (AAA) for remote controller
Drain hose
Drain pipe cover
Knockout cover
Screw for 4 o 10mm
2
2
1
1
2
2
1
1
1
2
Q'ty
TECHNICAL CHANGES
MCFH-24NV - →MCFH-24NV -
1. Only model name has changed.
MUCFH-24NV - →MUCFH-24NV -
1. Ball valve has changed to stop valve.
2. Deicer P.C. board has changed.
2
MCFH-24NV -
PART NAMES AND FUNCTIONS
EB
INDOOR UNIT
EBEA
EBEA
2
RESET
CLOCK
g
MUCFH-24NV -
OUTDOOR UNIT
Air inlet
EB
Air outlet
MCFH-24NV -
EB
3
3
Indoor model
Function
Power supply
Capacity
Air flow(High)
Dehumidification
Power outlet
Running current
Power input
Auxiliary heater
Power factor
Starting current
Fan motor current
Model
Winding
resistance(at20:)
Dimensions WOHOD
Weight
Air direction
Sound level (High)
Fan speed (High)
Fan speed regulator
Thermistor RT11(at25:)
Thermistor RT12(at25:)
Outdoor model
Air flow (High)
Compressor motor current
Fan motor current
Model
Output
Winding
resistance(at20:)
Model
Winding
resistance(at20:)
Dimensions WOHOD
Weight
Sound level(High)
Fan speed(High)
Fan speed regulator
Refrigerant filling
capacity(R22)
Refrigerating oil (Model)
Thermistor RT61(at0:)
Thermistor RT63(at0:)
kW
K /h
L/h
A
A
W
A(kW)
%
A
A
"
mm
kg
dB
rpm
k"
k"
K /h
A
A
W
"
"
mm
kg
dB
rpm
kg
cc
k"
k"
Electrical
data
Fan
motor
Special
remarks
Compressor
Electrical
data
Fan
motor
Special
remarks
Capacity
Coefficient of performance(C.O.P)
Capacity
MCFH-24NV-
EB
Cooling
6.0
3.1
12.5-11.7
2,720-2,750
-
99-98
2.21-2.18
11.56-10.76
0.58
Heating
6.2
-
11.7-11.3
2,540-2,650
-
98-98
2.44-2.34
10.76-10.36
0.58
Single phase 220 - 240 V, 50Hz
840
25
59
0.36
RB4V36-AB
WHT-BLK 82.9 BLK-YLW 65.6
YLW-BLU 36.0 BLU- BRN 27.0
BRN-RED 13.7
1,100 ✕ 650 ✕ 180
26
5
48-48
1,310-1,330
3
10
10
MUCFH-24NV-
EB
2,640-2,760
NH-47VMDT
2,200
C-R 0.96 C-S 2.07
RA6V85-AA
WHT-BLK 62.7 BLK-YLW 30.2
YLW-RED 62.9
870 ✕ 850 ✕ 295
72
53
720-750
2
2.40
1.2 (MS32N1)
33.18
33.18
SPECIFICATION
NOTE:Test conditions are based on ISO 5151
Cooling : Indoor DB27°C WB19°C Heating : Indoor DB20°C WB15°C
Outdoor DB35°C WB(24°C) Outdoor DB 7°C WB 6°C
4
4
OUTLINES AND DIMENSIONS
MCFH-24NV -
INDOOR UNIT
(When installed on the floor)
50cm or more
50cm or more
(When installed on the ceiling)
EB
100cm or more
50cm or more
50cm or more
650
80.8 906 112.8
616.5
17042.5
56
160
17.5
16
1100
Liquid line
{9.52
93
77
Gas line
{15.88
114
113
Unit: mm
143
180
5
100 10
1000For 10 units or less
200
Outdoor Unit-Necessary surrounding clearance
(Concentrated installation)
The upper side must be open.
Outdoor Unit-Necessary surrounding clearance
200
10
10
10
Note:Allow adequate
upper clearance
150
500
500
Service space
Front opening
Handle
for moving
138
95
Rear piping hole
23
33
Rear fresh
air intake
Side air intake
7 24(1)295(11-5/8)
Outlet guide
installation hole
302
Air intake
Air intake
Air outlet
870(34-1/4)
185
(7-9/32)
185
(7-9/32)
500(19-11/16)
330(13)
362(14-1/4)
1715
39.5 27.5
Terminal block for indoor and outdoor unit connection
Handle for moving
179 524
441
337
352
403
553
850(33-7/16)
40 60524
Service panel
Refrigerant-pipe flared
connection [15.88 5/8F
Refrigerant-pipe flared
connection [9.52 3/8F
Knock out hole
for front piping
(refrigerant,drainage
and wiring)
Knock out hole
for right piping
(refrigerant,drainage
and wiring)
R20
R20
60
120
4553
25 max.
Knock out holes for
power line 2-[27
Standard bolt length
65
Front right piping holes-
detail figures
80
17
42
45
12
R6
104
33
Bottom
piping hole
2-U-shaped
notched
holes
Drain hole
Drain hole
2-12o23 Oval holes
(standard bolt M10)
Handle for moving
MUCFH-24NV -
EB
Unit: mm
6
TRANSFORMER
CONTACTOR
R.V. COIL RELAY
R.V. COIL
COMPRESSOR CONTACTOR
T61
X52
X62
21S4
52
VARISTOR
DEFROST TEMPERATURE THERMISTOR
AMBIENT TEMPERATURE THERMISTOR
SOLID STATE RELAY
SOLID STATE RELAY
TERMINAL BLOCK
NR61
RT61
RT63
SR61
SR62
TB
C1
C2
DSAR
F61
MC
MF
COMPRESSOR CAPACITOR
FAN MOTOR CAPACITOR
SURGE ABSORBER
FUSE(3.15A)
COMPRESSOR (INNER PROTECTOR)
FAN MOTOR (INNER PROTECTOR)
SYMBOL SYMBOL SYMBOLNAME NAME NAME
NOTES:
1.Use copper conductors only (For field wiring).
2.Since the indoor and outdoor unit connecting wires have polarity, connect them according to the numbers (3,2,N).
3.Symbols below indicate.
:Terminal block, :Connector
5
SOLID STATE RELAY
TERMINAL BLOCK
CONTACTOR
SR142~SR144
TB
52C
VANE MOTOR
VARISTOR
ROOM TEMP. THERMISTOR
COIL TEMP. THERMISTOR
MV
NR11
RT11
RT12
C11
F11
HIC1
MF
FAN MOTOR CAPACITOR
FUSE (3.15A)
DC/DC CONVERTER
FAN MOTOR(INNER PROTECTOR)
SYMBOL SYMBOL SYMBOLNAME NAME NAME
WIRING DIAGRAM
INDOOR UNIT
POWER
SUPPLY
CORD
~/N
220-240V
50Hz
TO OUTDOOR
UNIT
CONNECTING
GRN/YLW
NOTE:1. About the outdoor side 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
MODEL MCFH-24NV-
TB
GRN/YLW
N
BLU
L
WHT
N
BLU
2
WHT
DISP/
RECEIVER
P.C.BOARD
101CN113
5
5
3
RED
REMOTE
CONTROLLER
CN
4
SW/THERMO
P.C.BOARD
EB
HIC1
3
2
1
CN201
CN
151
4
52C
3
TRANS
BRN
ELECTRONIC CONTROL P.C BOARD
6
6
F11
MV
RT11
C11
NR11
SR144
SR143
SR142
SR141
CN
112
LDCOM
LDC11
LDC12
LDFH
LDFM
LDFL
LDFVL
22
WHT
ORN
RED
BLK
YLW
BLU
BRN
1
2
3
4
5
6
7
8
RT12
WHT
ORN
RED
BLK
YLW
BLU
BRN
GRN/YLW
MF
VG79B063H01
OUTDOOR UNIT
TO INDOOR UNIT
CONNECTING
MODEL MUCFH-24NV-
X62
X52
BLU
BLU
RT63
CN662
T61
WHT
52C
RT61
CN661
TB
3
2
N
WHT
DSAR
GRN/YLW
EB
MF
BLK
YLW
6543
YLW
BLK
SR62
SR61
DEICER PC BOARD
21
A2 A1
52C
WHT
WHT
321
CN711
NR61
ORN
RED
12
ORN
COM
RED
X62
X52
COM
F61
CN730
C1
C2
CN721
NO
TAB52
NO
WHT
RED
BLK
1
2
21S4
3
1
3
5
BLU
RED
BLU
WHT
S
C
MC
R
7
SG79J186H01
6
A: Refrigerant piping
Max.length
15m
Max. Height difference *
5m
REFRIGERANT SYSTEM DIAGRAM
MCFH-24NV-
INDOOR UNIT
Indoor
heat
exchanger
Coil temperature
thermistor
RT12
Room temperature
thermistor
RT11
Distributor
EB
Refrigerant pipe [15.88
(Option)
(with heat insulator)
Flared connection
Flared connection
Refrigerant pipe
(Option) [9.52
(with heat insulator)
Muffler
Stop valve
(with service port)
Accumulator
Check
valve
Strainer
Stop valve
4-way valve
Capillary tube
[3.0o[1.6o350
Capillary tube
Check
valve
Strainer
Compressor
Discharge pressure
regurator open
23.5Of/F
[3.0o[2.0o350
Capillary tube
[4.0o[2.4o200
Refrigerant flow in cooling
Refrigerant flow in heating
MUCFH-24NV-
OUTDOOR UNIT
Outdoor
heat
exchanger
EB
MAX. REFRIGERANT PIPING LENGTH & MAX. HEIGHT DIFFERENCE
Models
MCFH-24NV -
wIt does not matter which unit is higher.
EB
Refrigerant piping MAX. length : m
A
15
Piping size O.D. : mm
Gas Liquid
{15.88
{
9.52
ADDITIONAL REFRIGERANT CHARGE (R22 : g)
If pipe length exceeds 7m, additional refrigerant (R22) charge is required
Models
MCFH-24NV -
Calculation : og=65g/mo(Refrigerant piping length minus 7m)
EB
Outdoor unit:precharged
(up to 7m)
2,400 65 130 195 260 325 390 455 520
7m08m 9m 10m 11m 12m 13m 14m 15m
8
Refrigerant piping length (one way)
7
Air in
Air out
Wet-and dry-bulb
thermometers
FRONT VIEW
Wet-and dry-bulb
thermometers
BACK VIEW
PERFORMANCE CURVES
The standard data contained in these specifications apply only to the operation of the air conditioner under normal condition.
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
198~264V, 50Hz
(2) AIR FLOW
Air flow should be set at MAX..
(3) MAIN READINGS
COOLING
(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/dry-bulb temperature difference on the left side of the chart on page 16 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.
HEATING
(1) Indoor intake air dry-bulb temperature : ˚CDB
(2) Indoor outlet air dry-bulb temperature : ˚CDB
(3) Outdoor intake air wet-bulb temperature : ˚CWB
(4) Total input : W
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 inlet as shown in the figure, and at least 2 sets of wetand-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 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 the 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
14.7
13.4
12.1
10.9
9.7
8.5
MCFH-24NV- EB
29.0
26.7
24.5
22.3
20.0
17.8
15.6
13.4
OUTDOOR UNIT
MCFH-24NV- EB
9
OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT
240V
220V
240V
220V
0.7
0.6
0.5
0.4
0.3
0.2
15 18 20 25 30 32 35(:)
50 60 70 (%)
Ambient temperature (:)
Ambient humidity (%)
Outdoor low pressure
13
12
11
10
9
8
7
15 18 20 25 30 32 35(:)
50 60 70 (%)
Ambient temperature (:)
Ambient humidity (%)
Outdoor unit current (A)
(MPa•G)
7
6
4
3
2
5
(kgf/F• G)
13
11
9
7
0 2 5 10 15 20 25(:)
Ambient temperature (:)
Outdoor unit current (A)
HEAT operation
Condition Indoor : Dry bulb temerature 20.0:
Wet bulb temerature 14.5:
Outdoor : Dry bulb temerature 7, 15, 21:
Wet bulb temerature 6, 13, 15.3:
220-240V
COOL operation
1 Both indoor and outdoor units are under the same temperature/humidity condition.
Dry Bulb temperature (˚C)
20
25
30
2 Air flow should be set at MAX..
3 The unit of pressure has been changed to MPa on the international system of units(SI unit system).
The converted score against the traditional unit system can be gotten according to the formula below.
1(MPa • G) =10.2(kgf/ff• G)
Relative humidity (%)
50
60
70
MUCFH-24NV-
EB
10
8
RESET
CLOCK
g
Indication
Operation state
Difference
between set
temperatuer
and room
temperature
This shows that the air
conditioner is operating
to reach the target temperature.
Please wait until the
target temperature is
obtained.
This shows that the
room temperature is
approaching the target
temperature.
lighted
not lighted
Approx. 2 :
or more
Approx. 2 :
or less
Operation Indicator
OPERATION INDICATOR
lamp
The operation indicator at the right side of the indoor
unit indicates the operation state.
MICROPROCESSOR CONTROL
MCFH-24NV - MUCFH-24NV -
WIRELESS REMOTE CONTROLLER
EBEB
Once the operation mode are set, the same operation mode
can be repeated by simply turning the OPERATE/STOP 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 button on the remote con-
troller. OPERATION INDICATOR lamp of the indoor
unit will turn 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 initial room
temperature at start-up of the operation.
Initial room temperature
more than 25°C
23.0°C to 25°C
less than 23°C
mode
COOL mode of
“I FEEL CONTROL”
DRY mode of
“I FEEL CONTROL”
HEAT mode of
“I FEEL CONTROL”
INDOOR UNIT DISPLAY SECTION
● Once the mode is fixed, the mode will not change by
room temperature afterwards.
● Under the ON-TIMER( ) timer operation, mode is
determined according to the room temperature as the
operation starts.
● When the system is stopped with the OPERATE/ STOP
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”
Restart
COOL mode of
“I FEEL CONTROL”
or COOL mode
● When the system is restarted after 2 hours, the operation
mode is determined by the initial room temperature at
start-up of the operation.
Example
Previous operation
COOL mode of
“I FEEL CONTROL”
or COOL mode
Restart
COOL or DRY or HEAT
mode of “I FEEL CONTROL” that is determined
by
initial room temperature
at start-up of the
operation.
11
(4) The initial set temperature is decided by the initial room temperature.
Model
COOL mode of
“I FEEL CONTROL”
DRY mode of
“I FEEL CONTROL”
HEAT mode of
“I FEEL CONTROL”
w1 After the system restarts by the remote controller, the system operates with the previous set temperature regardless of
the initial set temperature.
The set temperature is calculated by the previous set temperature.
(5) TEMPERATURE buttons
In “I FEEL CONTROL” mode, set temperature is decided by the microprocessor based on the room temperature.
In addition, set temperature can be controlled by or TOO WARM or TOO COOL buttons when you feel too warm or too cool.
Each pressing the TOO WARM or TOO COOL button ,indoor unit receives the signal a beep tone.
Initial room temperature
26°C or more
26°C or less
23°C to 25°C
23°C or less 26°C
Initial set temperature
Initial room temperature
minus 2°C
Initial room temperature
minus 2°C
24°C
w1
● Fuzzy control
When the TOO COOL or TOO WARM button is pressed, the microprocessor changes the set temperature, considering
the room temperature, the frequency of pressing TOO COOL or TOO WARM button and the user’s preference to heat or
cold. So this is called “Fuzzy control”, and works only in “I FEEL CONTROL” operation.
In DRY mode of “I FEEL CONTROL”, the set temperature doesn’t change.
▲TOO
COOL… To raise the set temperature 1~2 degrees(°C)
▼ TOO
WARM … To lower the set temperature 1~2 degrees(°C)
12
— COOL mode of “I FEEL CONTROL” —
1deg.
2deg. 4deg.
1.7deg.
NOTE : Coil frost prevention during COOL mode of “I FEEL CONTROL”
There are two types of controls in coil frost prevention as follows.
1 Temperature control
When the indoor coil thermistor RT12 reads -1°C or below, the coil frost prevention mode starts immediately.
However the coil frost prevention will not work for 5 minutes after the compressor starts.
During the coil frost prevention compressor stops and the indoor fan operates at the set speed for 5 minutes.
After that, if RT12 still reads below -1°C, this mode is prolonged until the RT12 reads over -1°C.
2 Time control
When the three conditions below have been satisfied for 1 hour and 45 minutes, compressor stops for 3 minutes.
a. Compressor has been continuously operating.
b. Indoor fan speed is Low or Med..
c. Room temperature is below 26°C.
When compressor stops ,the accumulated time is cancelled and when compressor restarts, time counting starts from
the beginning.
Time counting also stops temporarily when the indoor fan speed becomes High or the room temperature exceeds 26°C.
However, when two of the above conditions (b.And c.) are satisfied again time accumulation is resumed.
● Indoor fan operates at the set speed by FAN SPEED CONTROL button.
Followings are the fan speed in AUTO.
Initial temperature difference Fan speed
Room temperature minus set temperature : 2 degrees or more·········································High
Room temperature minus set temperature : 1 degree or more and less than 2 degrees···Med.
Room temperature minus set temperature : less than 1 degree·········································Low
—DRY mode of “I FEEL CONTROL”—
The system for dry operation uses the same refrigerant circuit as the cooling circuit.
The compressor and the indoor fan are controlled by the temperature and the microprocessor.
By such controls, indoor air flow amounts will be reduced in order to lower humidity without much room temperature
decrease.
The operation of the compressor and indoor fan is as follows.
1. When the room temperature is 23°C or over:
Compressor operates by temperature control and time control.
1 Set temperature is controlled to fall 2°C above from initial set temperature.
2 When the thermostat is ON, the compressor repeats 8 minutes ON and 3 minutes OFF.
When the thermostat is OFF, the compressor repeats 4 minutes OFF and 1 minute ON.
Indoor fan and outdoor fan operate in the same cycle as the compressor.
2. When the room temperature is under 23°C.
When the thermostat is ON, the compressor repeats 2 minutes ON and 3 minutes OFF.
When the thermostat is OFF, the compressor repeats 4 minutes OFF and 1 minute ON.
13
Operation time chart
Example
Thermostat
OFF
1st ON
ON
OFF
Indoor fan
Outdoor fan
compressor
OFF
OFF
ON
ON
8 min.
ON
OFF
ON
OFF
3 min.
OFF
OFF
4 min.
ON
ON
1 min.
NOTE ● Coil frost prevention during DRY mode of “I FEEL CONTROL”
The operation is same as that of coil frost prevention during COOL mode of “I FEEL CONTROL”.
However the indoor fan speed becomes the set speed or Low.
— HEAT mode of “I FEEL CONTROL” —
1. Indoor fan speed control
(1) Followings are the fan speed in AUTO.
Initial temperature difference Fan speed
Room temperature minus set temperature: 2 degrees or more·········································High
Room temperature minus set temperature: 1 degree or more and less than 2 degrees···Med.
Room temperature minus set temperature: less than 1 degree·········································Low
(2) Cold air prevention control
The fan runs at set speed when the indoor coil thermistor RT12 temperature exceeds 22°C. The fan operates at Very
Low when the temperature is below 18°C. But the fan stops when the indoor fan operates at Very Low and the room
temperature is 15°C or less. Released
Cold Air Prevention
NOTE : At initial in hysteresis this control works.
18°C
22°C
(3) New warm air control.
When compressor starts in heating operation or after defrosting, the fan changes the speed with dependence on the
indoor coil thermistor RT12 temperature to blow out warm air.
After releasing of cold air prevention, when the indoor coil temperature is 37°C or above, the fan speed shifts to the set
speed, and when the fan speed is changed by the remote controller, the fan speed is the set speed.
When the indoor coil temperature is less than 37°C, the fan speed is controlled by time as below.
<Time condition> <Indoor fan speed>
less than 2 minutes························Low
2 minutes to 4 minutes···················Med.
4 minutes or more··························High
The upper limit of the fan speed is the set speed.
If the thermostat turns off, this operation changes to flow soft control.
(4) Flow soft control
After the thermostat turns off, the indoor fan operates at Very Low.
NOTE : When the thermostat turns on, the fan operates at the set speed. Due to the cold air prevention control, the fan
does not start until the indoor coil thermistor RT12 reads 22°C or more.
1 deg.
2 deg.
1.7 deg.
4 deg.
14
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