Mitsubishi Electric MXZ-3C24NA Service Manual page 74

11-7. TEST POINT DIAGRAM AND VOLTAGE
1. Outdoor control P.C. board
MXZ-3C24NA MXZ-3C30NA
MXZ-4C36NA MXZ-5C42NA
MXZ-2C20NAHZ MXZ-3C24NAHZ
MXZ-3C30NAHZ
CN741
Signal translation
(To Communication
adaptor board)
CN930
To fan motor
Bus-bur voltage
290 ~ 370 VDC
15 VDC
Rotate instruction
(Constant voltage)
Rotate signal
(Pulse wave)
CNDC
Bus-bur
voltage
290 ~ 370
VDC
CN63H
High
pressure
switch
OBH702A
Serial signal 12 ~ 24 V
230 VDC Room A
Room B Room C Room D Room E
Input
CN601
74
CN621
CN611
LED3
LED2
LED1
Discharge temperature thermistor (RT62)
700
600
500
400
LEV: 12 VDC
300
pulse wave
200
100
0
0 10 20
32 50 68
Thermistor R100 = 13.36 k ± 2%
B constant = 4014 ± 2%
Rt = 13.36exp{4014(
t : ºC = (ºF - 32)/1.8
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 0 10 20
-4 14 32 50 68
Temperature
Thermistor R25 = 10 k ± 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 VAC
Input
CN714 Base heater
208/230 VAC
Input
CN713 Valve coil
208/230 VAC
Input
CN712 R.V. coil
208/230 VAC
Input
CNTH2
Ambient temperature
thermistor
(RT65)
CNTH1
Outdoor heat exchanger
temperature thermistor
(RT68)
Discharge temperature
thermistor (RT62)
Defrost thermistor
(RT61)
SW1
SW871
SW872
SW2
30 40 50 60 70 80 90 100 110 120
86 104 122 140 158 176 194 212 230 248
Temperature
1 1
)}
273+t 373
30 40 (ºC)
86 104 (ºF)
1
)}
298
(ºC)
(ºF)