Daikin Outdoor Heat Pump RXL12QMVJU

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

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

If voltage is not about 0V, stop the procedure and report the issue

Resistance between the pins of the DB1

If the resistance is infinity or less than 1 k(omega), short circuit occurs on the main circuit.

Sign off on the main circuit short check

Fan motor wire breakdown/short circuit check

(1) Check the connector for connection.

(3) Check if each resistance at the phases U - V and V - W is within specified range in the table below.

(1) Check the connector for connection.

(2) Check the motor control voltage is generated (between the pins 2 - 3).

Warning: This check requires trained personnel with PPE!

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

Is the power supply waveform a sine wave?

Is there waveform disturbance near the zero-cross?

Sign off on the power supply waveform check

Warning: Ensure operation is off and power is off before starting the procedure

Disconnect the connector S70 or S71

Control voltage between the pins 4 - 3

Rotation command voltage between the pins 4 - 2

Keep operation off and power off. Connect the connector S70 or S71

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

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