Daikin Outdoor Heat Pump RX71GV1B8

Warning: This check requires trained personnel with PPE!

Before this check, be sure to check the main circuit for short circuit.

With the circuit breaker still on, measure the voltage according to the drawing of the model in question. Be careful never to touch any live parts.

Voltage between P (+) and N (–)

The surface of the test points (P, N) may be covered with the coating. Be sure to make firm contact between the multimeter probes and the test points.

Sign off on the capacitor voltage check

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

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

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?

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

Enter the resistance between the terminals of the power module

Enter the resistance between the terminals of the compressor

Evaluate the measurement results

Sign off on the power module check

Check No.16: Make sure that the voltage of 320 is applied.

1. Set operation off and power off. Disconnect the connector S70.

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

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

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

5. Keep operation off and power off. Connect the connector S70.

6. Check whether 4 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.

If NG in step 2 → Defective PCB → Replace the outdoor unit PCB (main PCB).