Daikin Cooling-Only Outdoor Unit RKB24AXVJU

Set operation off and power off. Disconnect the connector S71.

Control voltage between the pins 3 & 4

Rotation command voltage between the pins 2 & 4

Keep operation off and power off. Connect the connector S71.

Pulses output at the pins 1 - 4 when the fan motor is rotated 1 turn by hand

If NG in step 2 : Defective PCB and replace the outdoor unit PCB.

If NG in step 4 : Defective Hall IC and replace the outdoor fan motor.

Warning: Ensure the voltage between the terminal of Power transistor (+) and (-) is approx. 0 volt before proceeding

Voltage between the terminal of Power transistor (+) and (-) is approx. 0 volt

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

Measure resistance between power transistor (+) and (-) and the U terminal of the compressor connector

U terminal measurement within acceptable range

Measure resistance between power transistor (+) and (-) and the V terminal of the compressor connector

V terminal measurement within acceptable range

Measure resistance between power transistor (+) and (-) and the W terminal of the compressor connector

W terminal measurement within acceptable range

Warning: This check requires trained personnel with PPE!

Measure the power supply waveform between No. 1(Live) and No. 2(Neutral) on the terminal board

Upload the oscilloscope reading

Is the power supply waveform a sine wave?

Is there waveform disturbance near the zero cross?

Sign off on the power supply waveforms check

Warning: Ensure the voltage between (+) and (-) of the diode bridge (DB1) is approximately 0 V before proceeding

Enter the resistance between the pins of the DB1

Is the resistance ∞ or less than 1 kW?

If the resistance is ∞ or less than 1 kW, a short circuit occurs on the main circuit.

In order to protect the environment, be sure to conduct pump down operation when relocating or disposing of the unit.

Remove the valve caps from the liquid stop valve and the gas stop valve.

Carry out forced cooling operation.

Close the liquid stop valve with a hexagonal wrench.

Close the gas stop valve and stop the forced cooling operation.

Sign off on the pump down maintenance