yes
Is supply wire securely connected?
replace PCB
no
yes
if failure disappear after PCB is changed
yes
Solve problem accordingly
Short connect that terminal
yes
Is ALARM terminal in mainboard disconnected?
Is an external alarm
connected to the system?
8) External alarm
no
An external alarm is identified
according to the list of fault codes
9) Overcurrent protection for single-phase fixed frequency models
Is supply voltage too low? Especially
when compressor starts up?
modify power supply circuit
no
no
re-wiring
yes
Is compressor current more than overcurrent protection
limit? Is current detecting circuit in good condition?
no
Confirm detecting circuit
is abnormal,replace
outdoor PCB
yes
Is compressor in good condition?
no
Is resistance of compressor
winding incorrect? Is it stuck?
replace compressor
yes
yes
Is running capacitor in good condition?
no
replace running capacitor
yes
Is pressure normal?
no
Check: 1. Is a valve in system shut off;
2. Is piping clogged;
3. Is system overfed; is there air in system;
4. (Cooling cycle) Is condenser dirty? Does outdoor fan motor run at low speed or stop?
5. (Heating cycle) Is evaporator or filter dirty? Does indoor fan motor run at low speed or stop?
6. Is ambient temperature too high? Is system overloaded?
-250-
Troubleshooting