Power Supply Waveforms Check; Electronic Expansion Valve Check - Daikin FTXS30LVJU Service Manual

SiUS091133
5.4

Power Supply Waveforms Check

Check No.11 Measure the power supply waveform between No. 1 and No. 2 on the terminal board, and check
the waveform disturbance.
 Check to see if the power supply waveform is a sine wave. (Fig.1)
 Check to see if there is waveform disturbance near the zero cross. (sections circled in Fig.2)
Fig.1
5.5

Electronic Expansion Valve Check

Check No.12
Conduct the followings to check the electronic expansion valve (EV).
1. Check to see if the EV connector is correctly connected to the PCB.
2. Turn the power off and on again, and check to see if the EV generates a latching sound.
3. If the EV does not generate a latching sound in the above step 2, disconnect the connector and
4. Check the continuity between the pins 1 - 6, 2 - 6, 3 - 6, and 4 - 6. If there is no continuity
5. If the continuity is confirmed in step 3, the outdoor unit PCB is faulty.
Note: Please note that the latching sound varies depending on the valve type.
Service Diagnosis
check the continuity using a tester.
between the pins, the EV coil is faulty.
Fig.2
Harness 5P
(5)
S20
Check
6P Connector
1 2 3 4 5 6
6-1
6-2
6-3
6-4
(R14212)
Check
144