Daikin Outdoor Unit Ceiling Mounted Cassette Type Heat Pump RX09RMVJU

Check No.16: Make sure that the voltage is within 320 VDC.

Set operation off and power off. 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 NG in step 2 -> Defective PCB -> Replace the outdoor unit PCB (main PCB).

Check the connection of connector

Check motor power supply voltage output (pins 5 ~ 8)

Check motor control voltage (pins 5 ~ 4)

Check rotation command voltage output (pins 5 ~ 3)

Check rotation pulse input (pins 5 - 2)

Sign off on the Indoor Fan Motor Connector Output Check

Check No.20: Check to make sure that the voltage between (+) and (–) of the diode bridge (DB1) is approximately 0 V before checking.

Enter the voltage between (+) and (–) of the diode bridge (DB1)

Measure the resistance between the pins of the DB1 referring to the table below.

Enter the resistance between the pins of the DB1

Is the resistance is  or less than 1 k?

If the resistance is  or less than 1 k, short circuit occurs on the main circuit.

Sign off on the main circuit short check

Warning: This check requires trained personnel with PPE!

Upload a photo of the power supply waveform between No. 1 and No. 2 on the terminal block

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: Disconnect the connectors of the thermistors from the PCB before proceeding

Thermistors disconnected from the PCB

Measure the resistance of each thermistor using a multimeter

Note: The data is for reference purpose only

Room temperature thermistor removed from the control PCB

Measure the resistance of the room temperature thermistor

Indoor heat exchanger thermistor removed

Measure the resistance of the indoor heat exchanger thermistor

Sign off on the thermistor resistance check