Daikin Outdoor Unit Heat Pump For Split System RXS25K3V1B

EV connector correctly connected to the PCB

EV generates a latching sound when power is turned off and on again

Continuity confirmed when connector is disconnected and checked with a multimeter

Check the continuity between the pins

If there is no continuity between the pins, the EV coil is faulty

If the continuity is confirmed, the outdoor unit PCB is faulty

Sign off on the electronic expansion valve check

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 after removal

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

Indoor heat exchanger thermistor removed from the PCB?

Measure the resistance of the indoor heat exchanger thermistor after removal

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

Control voltage between the pins 3 - 4

Rotation command voltage between the pins 2 - 4

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

RK(X)S25/35G2V1B9, RXS25/35J2V1B, RXS25K3V1B, RXS35K2V1B, RXS25/35L2V1B Procedure

Voltage between the pins 10 - 11

Hall IC generates the rotation pulse (0 ~ 15 VDC) 4 times between the pins 10 - 12, 10 - 13, when the fan motor is manually rotated once

Sign off on the rotation pulse 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 board

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: 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?

Follow the procedure below to 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