Daikin Outdoor Unit Heat Pump For Split System RXS25E2V1B

With the power on, operation off, and the connector connected, check the following

Output voltage of about 5 V between pins 1 and 3

Generation of 3 pulses between pins 2 and 3 when the fan motor is operating

If OK in both steps (1) and (2)

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

Thermistors disconnected from the PCB?

Measure the resistance of the room temperature thermistor using multimeter

If the room temperature thermistor is soldered on a PCB, remove the PCB from the control PCB to measure the resistance

Room temperature thermistor removed from the PCB?

Measure the resistance of the room temperature thermistor

If the connector of indoor heat exchanger thermistor is soldered on a PCB, remove the thermistor

Indoor heat exchanger thermistor removed from the PCB?

Measure the resistance of the indoor heat exchanger thermistor

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

RK(X)S25/35E2V1B, RK(X)S25/35G2V1B, RXS25/35L3V1B

Ensure the voltage of 320 ± 30 V is applied.

Set operation off and power off. Disconnect the connector S70 or S71.

Check that the voltage between the pins 4 - 7 is 320 VDC.

Check that the control voltage between the pins 3 - 4 is 15 VDC.

Check that the rotation command voltage between the pins 2 - 4 is 0 ~ 6.5 VDC.

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

Check whether 4 rotation pulses (0 ~ 15 VDC) are input 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.

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

Pressed the forced cooling operation ON/OFF button for 5 seconds?

Activate power transistor test operation from indoor unit