Inspection And Characteristics Of Parts - Panasonic U-72MF2U9 Service Manual

5. Inspection and Characteristics of Parts

(1) High-Pressure Switch (63PH1, 63PH2)
63PH1 Disconnect the CN3 connector (3P, white) from the Outdoor Unit Control PCB.
Measure the resistance between socket pins 1 and 3.
The resistance is OK if the result is 0 Ω.
63PH2 Disconnect the CN89 connector (2P, red) from the Outdoor Unit Control PCB.
Measure the resistance between socket pins 1 and 2.
The resistance is OK if the result is 0 Ω.
(2) Electronic Control Valve (MOV1, MOV2, MOV4)
After removing the connector from the PCB, use the following methods to check the valves.
MOV1 Measure the voltage between plug pin 5 and pins 1 through 4 at the CN64 connector (5P, white)
on the Outdoor Unit Control PCB.
(Because of the pulse output, a simplified measurement method is used.
Set the tester to the 12 V range; if the value displayed is approximately 4 V, then the voltage
is normal.)
When the voltage is normal, measure the resistance between each pair of pins on the electronic
control valve connector.
The connector is normal if all results (pin 5 – pin 1, pin 5 – pin 2, pin 5 – pin 3, pin 5 – pin 4)
are approximately 46Ω. (If the results are 0Ω or
MOV2 Measure the voltage between plug pin 5 and pins 1 through 4 at the CN63 connector (5P, red)
on the Outdoor Unit Control PCB.
(Because of the pulse output, a simplified measurement method is used.
Set the tester to the 12 V range; if the value displayed is approximately 4 V, then the voltage
is normal.)
When the voltage is normal, measure the resistance between each pair of pins on the electronic
control valve connector.
The connector is normal if all results (pin 5 – pin 1, pin 5 – pin 2, pin 5 – pin 3, pin 5 – pin 4)
are approximately 46Ω. (If the results are 0Ω or
MOV4 Measure the voltage between plug pin 5 and pins 1 through 4 at the CN57 connector (5P, blue)
on the Outdoor Unit Control PCB.
(Because of the pulse output, a simplified measurement method is used.
Set the tester to the 12 V range; if the value displayed is approximately 4 V, then the voltage
is normal.)
When the voltage is normal, measure the resistance between each pair of pins on the electronic
control valve connector.
The connector is normal if all results (pin 5 – pin 1, pin 5 – pin 2, pin 5 – pin 3, pin 5 – pin 4)
are approximately 46Ω. (If the results are 0Ω or
(3) Crankcase Heater
• Check the resistance of crankcase heater using a tester.
Under the value under the temperature 68°F, the result shows 1763 ± 7%.
, replace the coil.)
, replace the coil.)
, replace the coil.)
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3WAY VRF SYSTEM
Trouble Diagnosis
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