Service manual

[ VIII Troubleshooting ]
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HWE08010 GB
VIII Troubleshooting
[1] Troubleshooting
1. Check methods
1. Component and check points
(1) Thermistor
Room temperature thermistor (TH21)
Liquid pipe thermistor (TH22)
Gas pipe thermistor (TH23)
Disconnect the connector and measure the resistance between terminals with a tester.
(Ambient temperature 10°C - 30°C[50°F-86°F])
1) Thermistor characteristic graph
(2) Fan motor (CNMF)
Refer to the page on "DC fan motor (fan motor/indoor control board)."
(3) Linear expansion valve
Disconnect the connector, and measure the resistance between terminals with a tester.
Refer to the next page for details.
Normal Abnormal
4.3k - 9.6k Open or short
(Refer to the thermistor characteristic graph below.)
Low-temperature thermistor
Room temperature thermistor (TH21)
Liquid pipe thermistor (TH22)
Gas pipe thermistor (TH23)
Drain sensor (DS)
Thermistor R
0
= 15 k 3%
Multiplier of B = 3480 k 2%
0°C 32°F 15k
10°C 50°F 9.6k
20°C 68°F 6.3k
25°C 77°F 5.2k
30°C 86°F 4.3k
40°C 104°F 3.0k
(A) Temperature (°C)[°F]
(B) Resistance (k )
Normal Abnormal
1-5 2-6 3-5 4-6 Open or short
White-Red Yellow-Brown Orange-Red Blue-Brown
200 k 10%
(A) Brown (D) Orange
(B) Red (E) Yellow
(C) Blue (F) White
Rt = 15 exp { 3480( ) }
1
273+t
1
273
0
10
20
30
40
50
-20 -10 0 10 20 30 40 50
-4 14 32 50 68 86 104 122
(A)
(B)
1
2
3
4
5
6
LEV
M
(A)
(B)
(C)
(D)
(E)
(F)
CN60