Daikin Indoor Cooling/Heating Unit FXMQ72MVJU

Check for High Pressure in cooling

Check for High Pressure in heating

Check for broken wire of the relay wire (p.299)

Procedure for checking outdoor-outdoor unit transmission wiring for broken wires

Procedure for checking indoor-outdoor unit transmission wiring for broken wires

Check Fan Motor Connector (Power Supply Cable) (p.300)

Check Fan Motor Connector (Signal Cable) (p.300)

Warning: This procedure requires trained personnel with PPE!

Electronic Expansion Valve Coil Check

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

Measure the resistance value between pins

No continuity between White and Yellow

Resistance value between White and Orange

Resistance value between White and Red

Resistance value between Yellow and Blue

Resistance value between Yellow and Brown

Choose the type of vacuuming and dehydration

Normal vacuuming and dehydration

Enter the vacuum pump reading after 2 hours of operation

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

Enter the vacuum pump reading after additional 1 hour of operation if needed

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

Did the vacuum gauge reading rise after leaving the compressor in vacuum state for 1 hour?

Special vacuuming and dehydration

Enter the nitrogen gas pressure after vacuum break

Warning: This procedure requires trained personnel with PPE!

Enter the compressor capacity control

Refer to Compressor PI control for details

Low pressure protection control functional?

Hot gas bypass control functional?

Enter the superheated degree control of indoor unit electronic expansion valve

Enter the superheated degree control of outdoor unit electronic expansion valve

Warning: Ensure the power is OFF before starting the procedure

All wiring removed from the PCB

Prepare the analog type of multimeter. For the digital type of multimeter, those with diode check function are available for the checking

Wait for 10 minutes or more before proceeding

If using the analog type of multimeter, make measurement in resistance measurement mode in the x1 kΩ range

Measurement made in resistance measurement mode in the x1 kΩ range