Ipm Protection - Fujitsu AG * V09LAC Series Service Instruction

IPM Protection

[Checking Points]
Check the following points and locate the cause in the outdoor unit.
[Cause]
(1) Compressor failure
(2) Refrigeration cycle failure
(3) PC Board defective
(4) IPM defective
(5) Incorrect wiring
[First step]
Measure the DC voltage at terminals (between Electrolytic Capacitor and discharge resistance)
in the Inverter Controller Assy, and make sure it is lower than DC5V.
If it is higher than 5V, wait until the discharging is over.
Check point (1)
Open the Inverter Controller Assy
and check if there is abnormal points.
Go to Check point (2)
Check point (2)
1, Remove the lead of compressor.
2, Connect the P to minus and measure the U, V and W.
3, Check the balance of resistance. (+/- 10%)
4, Connect the N to plus and measure the U, V and W.
5, Check the balance of resistance. (+/- 10%)
*0W is failure even when resistance is the same
Check point (3)
Turn on the power and press TEST button
on Remote Control.
Is the outdoor fan rotating?
Go to Check point (3)
Check point (4)
Operate the unit for certain time and
check if the compressor is operating.
Check point (4)
Recheck, is compressor normal?
The unit is normal.
No(Abnormal)
Yes(Normal)
Yes(Normal)
Yes(Rotating)
Yes(Operating)
Yes(Operating)
Incorrect wiring > Correct and recheck
Parts touched > Correct and recheck
Parts broken
No(Abnormal)
No(Not rotating)
PCB or Compressor defective
No(Not operating)
IPM or PCB defective > Replace PCB
No(Not operating)
Please redo from the start.
(Refrigerant cycle has the possibility
of abnormalities.)
07-09
> Change the broken part
IPM defective