4. HOW TO CHECK THE PARTS

Parts name

Room temperature

thermistor (RT1) Pipe temperature

thermistor (RT2)

Fan motor (MF)

Relay connector

1 Red 1

3

White

 

3

5 Black 5

Protector

Vane motor (MV)

4Orange

5 Red

M

2Pink

Yellow

Brown

Blue

Connector 3 6 1

Check points

Disconnect the connector, then measure the resistance using a tester. (Surrounding temperature 50°F to 86°F)

Normal

Abnormal

4.3k' to 9.6k'

(Refer to the thermistor)

Open or short

Measure the resistance between the terminals using a tester.

Motor terminal

Normal

 

 

 

 

 

 

or

PKH

 

Abnormal

Relay connector

 

 

 

 

18,24FL

 

30,36FL

 

 

 

 

 

 

 

 

 

Red-White

99.5'i10%

 

62.6'i10%

Open or short

 

White-Black

103.5'i10%

 

74.0'i10%

 

 

Opening and closing temperature of protector.

Open: 266i41°F (Fan motor OFF)

Close: 176i68°F (Fan motor ON)

Measure the resistance between the terminals using a tester. (Surrounding temperature 68°F to 86°F)

 

Normal

Abnormal

 

 

 

Brown-Yellow

 

 

 

 

 

Brown-Blue

186 to 214'

Open or short

 

Red-Orange

 

 

 

 

 

Red-Pink

 

 

 

 

 

<Thermistor Characteristic graph>

 

 

Room temperature thermistor(RT1)

 

Thermistor for

 

Pipe temperature thermistor(RT2)

 

lower temperature

 

 

 

 

 

Thermistor R0=15k' ± 3%

Fixed number of B=3480k' ± 2%

Rt=15exp { 3480(

1

 

 

 

1

) }

273+t

273

 

 

 

32°F

15k'

 

 

 

 

 

 

50°F

9.6k'

 

 

 

 

 

 

68°F

6.3k'

 

 

 

 

 

 

77°F

5.4k'

 

 

 

 

 

 

86°F

4.3k'

 

 

 

 

 

 

104°F

3.0k'

 

 

 

 

 

 

Resistance (K")

< Thermistor for lower temperature >

50

40

30

20

10

0

-4 14 32 50 68 86 104 122

Temperature (°F)

44

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Mitsubishi Electronics PKH36FL, PKH24FL, PKH30FL, PKH18FL service manual HOW to Check the Parts, Check points