Power Supply Waveform Check; Electronic Expansion Valve Check - Daikin FTX-N Series Service Manual

SiUS091601EA
8.3

Power Supply Waveform Check

Check No.11
Measure the power supply waveform between No. 1 and No. 2 on the terminal strip, and check the
waveform disturbance.
 Check if the power supply waveform is a sine wave (Fig.1).
 Check if there is waveform disturbance near the zero-cross (sections circled in Fig.2).
[Fig.1]
8.4

Electronic Expansion Valve Check

Check No.12
Conduct the following to check the electronic expansion valve (EV).
1. Check if the EV connector is correctly connected to the PCB.
2. Turn the power off and on again, and check if the EV generates a latching sound.
3. If the EV does not generate a latching sound in step 2, disconnect the connector and check the
4. Check the continuity between the pins 5 - 1, 5 - 2, 5 - 3, 5 - 4 (between the pins 6 - 1, 6 - 2, 6 - 3,
5. If the continuity is confirmed in step 3, the outdoor unit PCB (main PCB) is faulty.
Part 6 Service Diagnosis
continuity using a multimeter.
and 6 - 4 for the 6P connector models). If there is no continuity between the pins, the EV coil is
faulty.
Harness 5P
S20 5P Connector
Check
1 2 3 4 5
[Fig.2]
(R1736)
5 - 1
5 - 2
5 - 3
S20
5 - 4
(R23663)
Harness 5P
6 - 1
(5)
6 - 2
Check
6P Connector
6 - 3
6 - 4
1 2 3 4 5 6
(R23593)
Check
(R1444)
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