Daikin Branch Selector Unit BS4Q54TVJ

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 Red

Resistance value between Yellow and Blue

Resistance value between Yellow and Brown

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!

Choose the type of vacuuming and dehydration

Vacuum pump enables vacuuming down to –100.7 kPa (–14.6 psi)?

Enter the vacuum level after 2 hours of evacuation

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

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

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

Did the leak tests pass (if conducted)?

Enter the vacuum level after leaving the compressor in vacuum state for 1 hour

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

Warning: This procedure requires trained personnel with PPE!

Compressor PI control in cooling mode

Low pressure protection control

Indoor unit electronic expansion valve for superheated degree control in cooling

Outdoor unit electronic expansion valve for superheated degree control in heating