Daikin Indoor Cooling/Heating Unit FXUQ24PVJU

Remove the connector for electronic expansion valve (X7A) from PCB

Measure the resistance value between White and Yellow pins

No continuity between White and Yellow

Measure the resistance value between White and Orange pins

Resistance value between White and Orange is approx. 300 Ω

Measure the resistance value between White and Red pins

Resistance value between White and Red is approx. 150 Ω

Measure the resistance value between Yellow and Blue pins

Resistance value between Yellow and Blue is approx. 300 Ω

Check for High Pressure in cooling, is the outdoor unit electronic expansion valve (main) fully open?

Check for High Pressure in heating, is the indoor unit electronic expansion valve used for “subcooled degree control”?

Check for broken wire of the relay wire

Procedure for checking outdoor-outdoor unit transmission wiring for broken wires: Is there continuity between the transmission wiring terminal blocks F1 and F2 of the central remote controller?

Procedure for checking indoor-outdoor unit transmission wiring for broken wires: Is there continuity between the transmission wirings F1 and F2 of the 'Indoor Unit a' that is farthest from the 'Outdoor Unit C'?

Check Fan Motor Connector (Power Supply Cable): Is the resistance between phases of U, V, W at the motor side connectors balanced and there is no short circuiting?

Check Fan Motor Connector (Signal Cable): Is the resistance between Vcc and each phase of U, V, W, and GND and each phase at the motor side connectors balanced within the range of ± 20 %?

Choose the type of vacuuming and dehydration

Vacuum pump connected to service ports of liquid pipe and gas pipe

Enter the vacuum level achieved after 2 hours of vacuuming

Did the vacuum level reach –100.7 kPa (–14.6 psi) or less after 2 hours?

Enter the vacuum level achieved after additional 1 hour of vacuuming (if required)

Did the vacuum level reach –100.7 kPa (–14.6 psi) or less after 3 hours?

Leak tests conducted (if required)

Compressor left at the degree of vacuum of –100.7 kPa (–14.6 psi) or less for a period of 1 hour or more

Did the vacuum gauge reading rise after 1 hour?

All wiring removed from the PCB where power transistors are mounted

Power supply turned OFF and 10 minutes or more have passed

Measurement mode for analog multimeter

Measurement in diode check mode for digital multimeter

Warning: This procedure requires trained personnel with PPE!

Compressor PI control in cooling

Low pressure protection control

Superheated degree control in cooling

Superheated degree control in heating

Enter the high pressure reading