Mitsubishi Electric MXZ-2A20NA - 1, Service Manual

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95
700
600
500
400
300
200
100
0
Resistance (k
Ω
)
Temperature (°F)
Discharge temperature thermistor (RT62)
32 50 68
86 104 122 140 158 176 194 212 230 248
-4 14 32 50 68 86 104
100
90
80
70
60
50
40
30
20
10
0
Resistance (k
Ω
)
Temperature (°F)
Except MXZ-2A20NA - , .
1 2
Defrost thermistor (RT61)
Ambient temperature thermistor (RT65)
Gas pipe temperature thermistor (RT6A,6B,6C)
Outdoor heat exchanger temperature
thermistor (RT68) 12-7. TEST POINT DIAGRAM AND VOLTAGE
1. Outdoor electronic control P.C. board
MXZ-2A20NA MXZ-2A20NA -
1
MXZ-2A20NA -
2
MXZ-3A30NA
LED 1
LED 2
Bus-bar
voltage
CN801
294 V DC
~
370 V DC
Input
(
(
(
LEV Room A
(
12 V DC pulse wave
(
LEV Room B
(
12 V DC pulse wave
(
LEV Room C
(
12 V DC pulse wave
(
High pressure switch
(
Gas pipe C thermistor
(
Gas pipe B thermistor
(
Gas pipe
A thermistor
CN932 20-90 V
AC
GND 5 V
5 V DC pulse wave
(
T
o
fan
motor
Defrost thermistor (R
T61)
Discharge temperature thermistor (R
T62)
Outdoor heat exchanger temperature thermistor (R
T68)
(
(
(+) (–)
(+)
Rush current relay
(–)
(–)R.V
. coil
(
12 V
DC
15 V 15 V
CN931
(+)
(–)
(
CN661
CN701 Signal transmission (T
o power board)
5 V DC pulse wave
(+) (–)
(
GND
CN702 Signal reception (From power board) 5 V DC pulse wave
GND (power board)
CN781
LEV E
(
(+) (–)
(
(+)
(–)
(
(+) (–)
(
CN791 CN792 CN793
CN681
CN662
( ( (
F801
FUSE
T3.15AL250V
LED 3
(
Ambient temperature thermistor (R
T65)
CN663
Serial signal Room C
12~24 V DC
Serial signal Room B
12~24 V DC
Serial signal
Room A
12~24 V DC
CN603
CN602
CN601
208/230 V AC
Input
SW1
CN795 12 V DC pulse wave
MXZ-3A30NA