Service manual

3 – 5
CAUTION: when attaching or removing the board
When operating only the outdoor unit (cooling 55 Hz fixed mode) To make only the outdoor unit run in cooling mode, and apply a voltage
of 220 ~ 240V AC to 1 and N on the terminal board and push the pump down switch (SW1).
(Avoid operating the outdoor unit alone for long periods of time.)
Thermistor No. Connector Color Connector pin
Compressor thermistor TH1 CN8A Red No. 1 to 2
Heat exchanger pipe thermistor TH2 CN8A Orange No. 3 to 4
100
80
60
40
20
0
-10 0 10 20 30 40
Resistance
Thermistor
Room temperature
Heat exchange
Pipe temperature
Color
Yellow
Orange
Black
Room temperature
thermistor TH1 (CN6 3 - 4 )
Heat exchange
thermistor TH2 (CN6 1 - 2 )
Pipe temperature
thermistor TH3 (CN6 5 - 6 )
Tester
CN6
1
6
Signal
TH1
TH2
TH3
Figure 1 Temperature properties of indoor thermistors
k
To measure the resistance, first remove
the soldering as shown at right.
Room temperature
thermistor TH1 (Yellow)
25ºC resistance 10 k
Heat exchange thermistor
TH2 (Orange), TH3 (Black)
25ºC resistance 4.431 k
500k
400k
300k
200k
100k
0
-20 0 20 60 80 100 120
3.06k
5.78k
2.28k
1.72k
40k
30k
20k
10k
0
-20 0 20 60
40
TH1 compressor thermistor
(CN8A 1 - 2 )
TH2 - TH4
TH6 - TH9
Temperature (ºC)
Temperature ( ºC)
25ºC resistance
45 k
Resistance ( )
Resistance ( )
0 ºC resistance
14.5 k
25
ºC resistance
4.431 k
4.17k
Figure 2 Temperature properties of outdoor thermistors
Connector
CN8A
Connector
CN8C
(MIH301C)
1
TH2 : Heat exchanger pipe thermistor (CN8A 3 - 4 )
TH3 : Outdoor temp. thermistor (CN8A 5 - 6 )
TH4 : Suction thermistor (CN8A7-8)
TH6 : Thermistor unit A (CN8C 1 - 2 )
TH7 : Thermistor unit B (CN8C 3 - 4 )
TH8 : Thermistor unit C (CN8C 5 - 6 )
TH9 : Thermistor unit D (CN8C 7 - 8 )
1
8
8