Daikin Daikin Branch Selector Unit BS4Q54TVJ BS4Q54TVJ

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

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

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

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

Judgement criteria of superheat operation:

Is the suction gas superheated degree 10°C (50°F) and over?

Discharge gas superheated degree

Is the discharge gas superheated degree 45°C (113°F) and over, except immediately after compressor starts up or is running under drooping control?

Additional notes on the superheat operation check

Sign off on the superheat operation 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!

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