14
TROUBLESHOOTING
7
7-1. HOW TO CHECK THE PARTS
PKFY-P24NKMU-E.TH PKFY-P30NKMU-E.TH
Parts name
Check points
Disconnect the connector then measure the resistance with a tester.
(At the ambient temperature 50°F~86°F)
Disconnect the connector then measure the resistance value with a tester.
(Coil temperature 68°F)
Vane motor (MV)
Linear expansion
valve (LEV)
Refer to 7-1-1.
Room temperature
thermistor (TH21)
Liquid pipe temperature
thermistor (TH22)
Gas pipe temperature
thermistor (TH23 ,24)
Normal
4.3k
~9.6k
Abnormal
Open or short
Normal
200
± 10%
Abnormal
(1)-(5)
White-Red
(2)-(6)
Yellow-Brown
(3)-(5)
Orange-Red
(4)-(6)
Blue-Brown
Open or short
Measure the resistance between the terminals with a tester. (Coil temperature 68°F)
Normal
250
± 7%
Abnormal
-
Brown-Red
-
Brown-Orange
-
Brown-Yellow
-
Brown-Green
Open or short
Fan motor (MF)
Red
Yellow
Brown
Orange
Green
Connect pin No.
M
1
2
3
4
5
6
LEV
White
Yellow
Orange
Blue
Red
Brown
CN60
Refer to 7-1-3.
7-1-2. Liner expansion valve
7-1-1. Thermistor
4
Φ
4
3
6
5
Φ
3
2
Φ
2
1
Φ
1
Φ
4
Φ
3
Φ
2
Φ
1
Controller board
Drive circuit
Connector(CN60)
DC12V
Brown
Red
Blue
Orange
Yellow
White
M
4
6
2
3
5
1
Blue
Brown
Yellow
Orange
Red
White
Linear expansion valve
<Thermistor characteristic graph>
Room temperature thermistor (TH21)
Liquid pipe temperature thermistor (TH22)
Gas pipe temperature thermistor (TH23) (TH24)
Thermistor R
0
=15k
Ω
± 3%
Fixed number of B=3480 ± 2%
Rt=15exp { 3480( ) }
30°F 15.8k
Ω
50°F
9.6k
Ω
70°F
6.0k
Ω
80°F
4.8k
Ω
90°F
3.9k
Ω
100°F 3.2k
Ω
Thermistor for
lower temperature
Operation summary of the linear expansion valve
• Linear expansion valve open/close through stepping motor after receiving the pulse signal from the indoor controller board.
• Valve position can be changed in proportion to the number of pulse signals.
<Connection between the indoor controller board and the linear expansion valve>
1
273+(t-32)/1.8
1
273
0
10
20
30
40
50
0
-20
20
40
60
80
100
120
< Thermistor for lower temperature >
Temperature (°F)
Resistance (k
Ω
)
