Daikin Outdoor Heat Pump RX50G2V1B

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

Warning: This procedure requires trained personnel with PPE!

Install an inverter analyzer instead of a compressor.

Charged voltage of the built-in smoothing electrolytic capacitor dropped to 10 VDC or below?

Terminals removed from the compressor?

Terminals connected to the terminals of the inverter analyzer without touching each other?

Activate the power transistor test operation from the outdoor unit.

Forced cooling operation ON/OFF button pressed for 5 seconds?

Diagnose according to 6 LEDs lighting status.

Warning: Ensure the power is off before starting the procedure

Disconnect the connectors of the thermistors from the PCB

Measure the resistance of each thermistor using a multimeter

Remove the PCB from the control PCB to measure the resistance if the room temperature thermistor is soldered on a PCB

Remove the thermistor and measure the resistance if the connector of indoor heat exchanger thermistor is soldered on a PCB

Sign off on the thermistor resistance check

Check the connection of connector

Check the motor power supply voltage output (pins 4 - 7)

Check the motor control voltage (pins 4 - 3)

Check the rotation command voltage (pins 4 - 2)

Check the rotation pulse (pins 4 - 1)

Sign off on the connector output check

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)

Sign off on the power supply waveforms check