Power Supply Waveform Check; Electronic Expansion Valve Check - Daikin FTKM-U Series Service Manual

Check
5.3

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]
5.4

Electronic Expansion Valve Check

Check No.12 Conduct the followings 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 the step 2 above, disconnect the connector
4. Check the continuity between the pins 5 - 1, 5 - 2, 5 - 3, 5 - 4 (for 5P connectors) and 6 - 1, 6
5. If the continuity is confirmed in step 3, the outdoor unit PCB (main PCB) is faulty.
92
and check the continuity using a multimeter.
- 2, 6 - 3, 6 - 4 (for 6P connectors). If there is no continuity between the pins, the EV coil is
faulty.
Harness 5P
S20 Check
5P Connector
1 2 3 4 5
[Fig.2]
(R1736)
5 - 1
5 - 2
S20
5 - 3
5 - 4
(R23840)
SiMX042215E
Harness 5P
6 - 1
(5)
6 - 2
Check
6P Connector
6 - 3
6 - 4
1 2 3 4 5 6
Part 6 Service Diagnosis
(R1444)
(R23593)