Daikin Indoor Cooling/Heating Unit FXMQ24PBVJU

Check for High Pressure in cooling

Check for High Pressure in heating

Check for broken wire of the relay wire

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

Turn OFF the power supply to all equipment

Short circuit between the outdoor-outdoor unit terminal F1 and F2 in the 'Outdoor Unit A'

Conduct continuity checks between the transmission wiring terminal blocks F1 and F2 of the central remote controller using a multimeter

Superheating temperature control in cooling is conducted by indoor unit electronic expansion valve

Is the indoor unit electronic expansion valve functioning properly?

Superheating temperature control in heating is conducted by outdoor unit electronic expansion valve (main)

Is the outdoor unit electronic expansion valve functioning properly?

Judgement criteria of superheat operation: Suction gas superheated degree: 10°C (50°F) and over. Discharge gas superheated degree: 45°C (113°F) and over, except immediately after compressor starts up or is running under drooping control

Enter the suction gas superheated degree

Enter the discharge gas superheated degree

Does the superheat operation meet the judgement criteria?

Sign off on the superheat operation check

All wiring removed from the PCB where power transistors are mounted on

Measurement of resistance made after a lapse of 10 minutes or more

Measurement made in resistance measurement mode in the x1 kΩ range when using the analog type of multimeter

Measurement made in diode check mode when using the digital type of multimeter

Sign off on the power transistor check

Overload control causing insufficient cooling capacity

Superheated degree of suction gas

Compressor lower in discharge pipe temperature despite of pressure loads

In heating, the temperature of discharge air through the subcooled section becomes lower

Superheated degree of suction gas

Warning: This procedure requires trained personnel with PPE!

Electronic Expansion Valve Coil checked

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 Orange is approx. 300 Ω

Resistance value between White and Red

Resistance value between White and Red is approx. 150 Ω