3
) Low pressure protection
Confirm the fault according
to the fault code list
Are connectors of pressure switch in good
condition?
no
Check and reconnect
yes
Is low side pressure switch
activated? (If not, DC voltage is 0V.)
no
Replace PCB
Is the low side pressure detected by
the gage lower than threshold value?
The threshold value is indicated on
the switch
yes
yes
no
Replace low pressure
switch
yes
if outdoor stop valves of gas pipe
and liquid pipe are open totally
no
Open the valves
yes
Is piping twisted or deformed?
yes
Repair pipe
no
Does indoor fan work properly during
cooling cycle? Does outdoor fan work
properly during heating cycle?
no
Repair fan motor or fan
capacitor
yes
Is indoor filter or heat
exchanger dirty?
yes
Cleaning
no
Measure equalized pressure and time to
reach equalization to see if the system has
leakage. Lack of refrigerant? Is capillary
blocked?
yes Conduct leak test.
Evacuate and recharge
no
Bad operation codition, such as ultra low
outdoor temperature
Model: AD182ALERA AD362AHERA
Commercial Air Conditioner
38