Haier AP482AKEAA Service Manual page 35

7) High current protection in 3-phase fixed frequency models
Is three-phase circuit not
balanced? Is supply voltage too
low? Is supply voltage too low at
compressor start-up?
yes
Is power cable or compressor wire
securely connected? Properly?
yes
Is compressor current more than overcurrent
protection limit? Is current detecting circuit in
good condition?
yes
Is AC contactor in
poor contact?
yes
if compressor is normal
yes
if pressure is 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?
8) External alarm
An external alarm is
identified according to the
list of fault codes
Is an external alarm
connected to the system?
no
Is ALARM terminal in
mainboard disconnected?
yes
Short connect that
terminal
yes
if failure disappear after
PCB is changed
no
replace PCB
Commercial Air Conditioner
yes
Modify power supply circuit
no
re-wiring
no
yes
replace AC contactor
no
Is resistance of compressor
winding incorrect? Is it stuck?
yes
Solve problem
accordingly
Model: AP*****EAA AU*****EAA
Confirm detecting circuit
is abnormal,replace
outdoor PCB
yes
35
replace compressor