Daikin Outdoor Heat Pump RX71GV1B9

Check No.11: Power Supply Waveforms Check

Measure the power supply waveform between No. 1 and No. 2 on the terminal board

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)

Upload a photo of the measured waveform

Sign off on the power supply waveforms check

Warning: This check requires trained personnel with PPE!

Main circuit checked for short circuit?

Warning: Never touch any live parts during the check.

Voltage between P (+) and N (-)

Sign off on the capacitor voltage check

Warning: This check is only for RX50/60G2V1B9, RX50/60G3V1B, RX60G4V1B models

Voltage between (+) and (–) of the diode bridge (DB1)

Ensure the voltage is about 0 V before proceeding

Resistance between the pins of the DB1

Is the resistance ∞ or less than 1 kΩ?

If yes, a short circuit occurs on the main circuit.

Sign off on the main circuit short check

EV connector correctly connected to the PCB

EV generates a latching sound when power is turned off and on again

Continuity confirmed when connector is disconnected and checked with a multimeter

Check the continuity between the pins

If there is no continuity between the pins, the EV coil is faulty

If the continuity is confirmed, the outdoor unit PCB is faulty

Sign off on the electronic expansion valve check

Warning: Ensure the voltage between (+) and (-) of the power module is about 0 V before proceeding.

Voltage between (+) and (-) of the power module is about 0 V?

Disconnect the compressor harness connector from the outdoor unit PCB. To disengage the connector, press the protrusion on the connector.

Compressor harness connector disconnected from the outdoor unit PCB?

Measure resistance between the terminals of the power module and the terminals of the compressor with a multimeter.

Enter the resistance measurement

Evaluate the measurement results

Sign off on the power module check