Daikin Cooling-Only Outdoor Unit RKB18AXVJU

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.

Sign off on the main circuit short check

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

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.

4 pulses (0 ~ 15 VDC) are output at the pins 1 - 4 when the fan motor is rotated 1 turn by hand

When the fuse is melted, check the outdoor fan motor for proper function.

If NG in step 2 : Defective PCB

If NG in step 4 : Defective Hall IC

EXV connector correctly connected to PCB

EXV generates a latching sound after power cycle

If EXV does not generate a latching sound, proceed to next step

Continuity confirmed using a multimeter after disconnecting connector

Check the continuity between pins

For harness 5P models, check the continuity between pins

If continuity is confirmed, proceed to next step

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