Troubleshooting; Check Methods - Mitsubishi Electric CITY MULTI PEFY-P06NMAU-E4 Technical & Service Manual

[ VIII Troubleshooting ]
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])
Normal
4.3k - 9.6k
(Refer to the thermistor characteristic graph below.)
1) Thermistor characteristic graph
Low-temperature thermistor
Room temperature thermistor (TH21)
Liquid pipe thermistor (TH22)
Gas pipe thermistor (TH23)
Drain sensor (DS)
Thermistor R = 15 k
0
Multiplier of B = 3480 k
Rt = 15 exp { 3480(
273+t
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
(B) Resistance
(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.
CN60
(F)
1
(E)
2
(D)
3
M
(C)
4
LEV
(A)
6
(A) Red
(C) Blue
(D) Orange
HWE20150
Abnormal
Open or short
3%
2%
1
1
) }
273
(°C)[°F]
(k )
Normal
1-6 2-6
White-Red Yellow-Red
(150Ω) ±10%
(E) Yellow
(F) White
50
40
30
20
10
0
-20 -10 0 10 20 30
-4 14 32 50 68 86
(A)
3-6 4-6
Orange-Red Blue-Red
- 25 -
40 50
104 122
Abnormal
Open or short
GB