Mitsubishi Electric MSZ-LN-VG Series Service Manual page 122

2. Outdoor control P.C. board
MXZ-3F54VF MXZ-3F68VF
MXZ-3F54VF2 MXZ-3F68VF2 MXZ-4F72VF2 MXZ-4F80VF2
MXZ-3F54VF3 MXZ-3F68VF3 MXZ-4F72VF3 MXZ-4F80VF3
CN741
Signal translation
(To Communication
adaptor board)
V (Rotate signal)
FG
(Voltage between
right pins of PC931,
pin 3 and pin 4)
(Correspond to
(CNF1 (+)- (−))
V (Rotate instruction)
SP
(Voltage between pins
of C930): 0 V DC
(when stopped),
1.8 - 6.5 V DC
(when operated)
(Same as
(CNF1 (+)- (−))
CNF1
To fan motor
Bus-bar voltage
290 - 370 V DC
15 V DC
Rotate instruction
(Constant voltage)
Rotate signal
(Pulse wave)
CNDC
Bus-bar
voltage
290 - 370
V DC
CN63H
High
pressure
switch
CN702
Signal transmission
15 V
(To power board)
5 V DC pulse wave
15 V
CN701
Signal transmission
(To power board)
5 V DC pulse wave
OBH790D
MXZ-4F72VF
220 - 230 - 240 V AC
Room A
Input
CN601
(+)
(-)
(-)
(-)
(-)
(+)
Serial signal 12 ~ 24 V
Room B
Room D
Room C
CN621
CN611
CN793 CN791
LEV Room C LEV Room A
CN794 CN792
LEV Room D LEV Room B
CN797
LEV R
LEV: 12 V DC
pulse wave
122
Defrost thermistor (RT61)
Ambient temperature thermistor (RT65)
Outdoor heat exchanger temperature
thermistor (RT68)
100
90
80
70
60
50
40
30
20
10
0
-20 -10
Thermistor R25 = 10 kΩ ± 2%
B constant = 3950 ± 2%
Rt = 10exp{3950(
F711 FUSE
T3.15AL250V
CNAC
to outdoor power P.C. board
220 - 230 - 240 V AC
Input
CN714 Defrost heater
220 - 230 - 240 V AC
Output
CN712 R.V. coil
220 - 230 - 240 V AC
Output
CNTH2
Ambient temperature
thermistor
(RT65)
CNTH1
Outdoor heat exchanger
temperature thermistor
(RT68)
Discharge temperature
thermistor (RT62)
Defrost thermistor (RT61)
SW1
SW871
SW2
LED3
LED2
LED1
Discharge temperature thermistor (RT62)
800
700
600
500
400
300
200
100
0
0 10 20 30 40 50 60 70 80 90 100 110 120
Temperature( )
Thermistor R100 = 13.36 kΩ ± 2%
B constant = 4014 ± 2%
Rt = 13.36exp{4014(
0 10 20 30 40 (ºC)
Temperature
1 1
)}
273+t 298
1 1
)}
273+t 373