Mitsubishi Electric MXZ-2C20NA2 Service Manual page 129

1. Outdoor control P.C. board
MXZ-2C20NA4
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
15 V
CN701
Signal transmission
(To power board)
5 V DC pulse wave
OBH702N
Discharge temperature thermistor (RT62)
700
600
500
400
300
200
100
0
0 10
32 50
Thermistor R100 = 13.36 kΩ ± 2% , B constant = 4014 ± 2%
Rt = 13.36exp{4014(
Serial signal 12 ~ 24 V
Room A Room B
208/230 V AC
Input
CN601
(-)
(+)
129
20 30 40 50 60 70 80 90 100 110 120
68 86 104 122 140 158 176 194 212 230 248
Temperature
1 1
)} , t: ºC = (ºF - 32)/1.8
273+t 373
CN621
CN611
CN791 LED3
LED2
LEV Room A
LED1
CN792
LEV Room B
CN797
LEV R
LEV: 12 V DC
pulse wave
Defrost thermistor (RT61)
Ambient temperature thermistor (RT65)
Outdoor heat exchanger temperature
thermistor (RT68)
100
90
80
70
60
50
(ºC)
(ºF)
40
30
20
10
0
-20 -10 0 10 20
-4 14 32 50 68
Temperature
Thermistor R25 = 10 kΩ ± 2%
B constant = 3950 ± 2%
1
Rt = 10exp{3950(
273+t
t : ºC = (ºF - 32)/1.8
F711 FUSE
T3.15AL250V
CNAC
to outdoor power P.C. board
208/230 V AC
Input
CN714 Defrost heater
208/230 V AC
Output
CN712 R.V. coil
208/230 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
30 40 (ºC)
86 104 (ºF)
1
)}
298