Abnormal increases or decreases in voltage are detected by 
checking the specified voltage detection circuit. 
Check  the power supply. Is it 
in working order? 
Check the connections and 
w i r e s .  Are  they  in  working 
order? 
Turn off the unit
No
Yes
No
Ensure proper connections or 
replace the wires
Yes
Replace the reactor
Yes
No Replace the IPM board
Turn power on and while the unit is on 
standby, check if the voltage between P 
and N is at DC 310V, 340V or 380V?  
Then start up the unit and measure the 
voltage between P and N. Is it in now 
between 220V~400V?
 Check the reactor. Is it in 
working order? 
Yes
No
Replace outdoor main PCB