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19-09-2016, 12:46 AM
Hi,
I'm trying to help a friend repair a Fujitsu AOT45LJBYL inverter split system.
A small lizard has cooked itself on the inverter PCB’s IPM IC and taken it & the compressor out.
They have been replaced by a fridgie, but the unit will not run and still has a communications failure between the ID & OD unit. The fridgie doesn’t know what the problem is. I have managed to find a basic circuit diagram for the unit.
The comms error E01 appears to be caused by an inverter board no power issue. The bridge rectifier is ok (diode check & 240v dc with AFM disconnected), PTC measures around 30-40 ohms cold & looks/smells ok and appears doing it’s job with too much current present at power up (Mulitmeter Peak AC current is 2.4A before its limited) & the issue is possibly a faulty AFM module (assuming the new inverter board is ok). F2 & F4 are still ok on the inverter board. Results from AFM Multimeter checks from post http://www.refrigeration-engineer.com/forums/showthread.php?15069-Fujitsu-General-Fault as per table below measured value column. Diode resistance checks are a bit out of spec, so I checked with diode MM function. If I isolate the AFM from the Inverter board there is 240v DC between P & N (as expected as the filter caps are on the inverter board), but when the inverter board is connected I have 1-2v dc between P&N (not the 340v DC I was expecting probably due to the PTC current limiting). Also tried disconnecting FM1& FM2 & compressor from the inverter board, but no change even if PTC is cool. Looking at the cct diag I should also try disconnecting CN34 to isolate the 4 way valve (haven't tried it yet). Does anybody know if the AFM can be bypassed temporarily for testing (quick 10 second test) to prove whether it’s faulty & causing the PTC to overload? I would disconnect the ACTPM connector & connect W14 to the BR +ve & W15 to the BR –ve.
Thanks for your time.
14325
I'm trying to help a friend repair a Fujitsu AOT45LJBYL inverter split system.
A small lizard has cooked itself on the inverter PCB’s IPM IC and taken it & the compressor out.
They have been replaced by a fridgie, but the unit will not run and still has a communications failure between the ID & OD unit. The fridgie doesn’t know what the problem is. I have managed to find a basic circuit diagram for the unit.
The comms error E01 appears to be caused by an inverter board no power issue. The bridge rectifier is ok (diode check & 240v dc with AFM disconnected), PTC measures around 30-40 ohms cold & looks/smells ok and appears doing it’s job with too much current present at power up (Mulitmeter Peak AC current is 2.4A before its limited) & the issue is possibly a faulty AFM module (assuming the new inverter board is ok). F2 & F4 are still ok on the inverter board. Results from AFM Multimeter checks from post http://www.refrigeration-engineer.com/forums/showthread.php?15069-Fujitsu-General-Fault as per table below measured value column. Diode resistance checks are a bit out of spec, so I checked with diode MM function. If I isolate the AFM from the Inverter board there is 240v DC between P & N (as expected as the filter caps are on the inverter board), but when the inverter board is connected I have 1-2v dc between P&N (not the 340v DC I was expecting probably due to the PTC current limiting). Also tried disconnecting FM1& FM2 & compressor from the inverter board, but no change even if PTC is cool. Looking at the cct diag I should also try disconnecting CN34 to isolate the 4 way valve (haven't tried it yet). Does anybody know if the AFM can be bypassed temporarily for testing (quick 10 second test) to prove whether it’s faulty & causing the PTC to overload? I would disconnect the ACTPM connector & connect W14 to the BR +ve & W15 to the BR –ve.
Thanks for your time.
14325