Daikin Indoor Unit Wall Mounted Type Air Conditioner FTX50K2V1B

Warning: This check requires trained personnel with PPE!

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

Is the power supply waveform a sine wave (Fig.1)?

Is there waveform disturbance near the zero-cross (sections circled in Fig.2)?

Upload a photo of the measured waveform

Sign off on the power supply waveforms check

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 indoor unit?

Diagnose method (Diagnose according to 6 LEDs lighting status.)

Warning: Ensure the voltage between (+) and (–) of the diode bridge (DB1) is about 0 V before proceeding

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 ∞ or less than 1 kΩ?

If the resistance is ∞ or less than 1 kΩ, short circuit occurs on the main circuit.

Sign off on the main circuit short check

Ensure that the voltage of 320 + 100 V ~ 320 - 50 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: Ensure the voltage between (+) and (–) of the power module is about 0 V before proceeding

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

Measure resistance between the terminals of the power module

Measure resistance between the terminals of the compressor

Evaluate the measurement results

Sign off on the power module check