Fujitsu AO*12LFBC, Service Instructions Manual

Page: 59 / 83

Active Filter Failure
[Checking points]
Check the following points and locae the cause in the outdoor unit.
[Cause]
(1) Incorrect wiring
(2) Active Filter Module defective
(3) PC Board defective
(4) DC voltage detectiion circuit defective
[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.
Open the Inverter Controller Assy
and check if there is abnormal points.
Incorrect wiring > Correct and recheck
(Incorrect wiring, Parts touched, Parts broken)
Parts touched > Correct and recheck
Parts broken > Change the broken part
Turn on the power and press TEST button
on Remote Control.
Is the outdoor fan rotating?
Operate the unit for certain time and
measure the terminal voltage of the
The unit is normal.
discharge resistance.
Is the DC voltage between 350 to 425V?
Recheck
Operate the unit for certain time and Yes(Operating) > Check completed
check if the compressor is operating. No(Not operating) > Return to the start
Check point (1)
Yes(Normal)
Go to Check point (2)
No(Abnormal)
Check point (2)
Yes(Rotating)
Go to Check point (3)
No(Not rotating)
Check point (3)
Yes(Within range)
No(Out of range)
ACTPM or PCB defective > Replace Main PCB
ACTPM or PCB defective > Replace ACTPM or
Main PCB.
(Replace only ACTPM if Main PCB was replaced
at Check point (2).)
07-10