Daikin Outdoor Heat Pump RXL18UMVJU

Warning: This check requires trained personnel with PPE!

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

Is the power supply waveform a sine wave (Refer to Fig.1)?

Is there waveform disturbance near the zero-cross (Refer to sections circled in Fig.2)?

Upload a photo of the measured waveform

Sign off on the power supply waveform 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

Power transistor test operation activated?

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

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

Connector disengaged successfully?

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

Warning: Disconnect the connector of thermistor ASSY from the PCB before proceeding

Enter the resistance value measured from the thermistor

Does the measured resistance value match the listed value?

If the measured resistance value does not match the listed value, the thermistor must be replaced.

To check the thermistor soldered on a PCB, disconnect the PCB from other PCB/parts

Enter the resistance value measured from the soldered thermistor

Does the measured resistance value match the listed value?

If the measured resistance value does not match the listed value, the thermistor must be replaced.

Sign off on the thermistor resistance check