Daikin Outdoor Unit Multi-Split Type Air Conditioner 2MXL18QMVJU

Warning: This check requires trained personnel with PPE!

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

Is the power supply waveform a sine wave as shown in Fig.1?

Is there any waveform disturbance near the zero-cross as shown in the sections circled in Fig.2?

Upload a photo of the measured waveform

Sign off on the power supply waveform check

Make sure that the voltage of 320 V is applied.

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

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

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

Check that the rotation command voltage between the pins 4 - 2 is 0 ~ 15 VDC.

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

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

When the fuse is melted, check the outdoor fan motor for proper function.

1. Check the connection of connector.

2. Check motor power supply voltage output (pins 4 - 7).

3. Check motor control voltage (pins 4 - 3).

4. Check rotation command voltage output (pins 4 - 2).

5. Check rotation pulse input (pins 4 - 1).

1. Check the connection of connector.

2. Check motor power supply voltage output (pins 5 - 8).

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?

Warning: Be careful not to let the terminals (U,V,W) touch each other. Otherwise, high voltage is applied.

Power transistor test operation activated from the outdoor unit?

Diagnose according to 6 LEDs lighting status.

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 indoor fan motor is operating

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