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hi, called to a site 2 weeks ago,problem wit wall mount...found the main mcb tripped and a neutral/live fuses blown on outdoor board which feed indoor,..so replaced fuses and tirned it on and went bang again....so went to indoor disconnected ind fan and tried again qand everything worked...so replaced indoor fan... started unit worked for about 4 days and went again, replacewd condensate pump just in case... system ran for a week and went again...anybody any ideasrgrds phil
Did you carefully check the power supply?
If there is a poor connection on N line you can have a 'floating N' problem.
Between earth & N there should be zero volts.
But if there is a poor N connection in the power supply line then there will be some measurable voltage between E & N at the outdoor unit & or indoor unt power supply terminals & silly voltage on the L line.
I have seen Mitsubishi split systems working with this problem 20 to 40 volts E to N. They may work for a week or two & then blow a board, some times the outdoor board & another time the indoor board.
If the N is completely disconected then the problem is easy to spot & boards tend to blow on first startup.
I had a problem like this some time ago. Found the geniuses that fitted the condensate pump had wired the live 240v onto the signal wire of the board thus blowing the outdoor fuses and boards.
You could also have a problem with condensate.
Check that all of the pipework is inside the drip tray as stray drops of water will short out the electrics and be dried out by the time you are called to the problem ;)
As will a short charge. Frost builds up where the pipes enter the evap and then when the unit switches off the defrost just overflows and causes a short.
Quote:
Originally Posted by philjd26
does the wall mount also have the "sub power pcb" in the indoor like on a few older mitsu ive seen? its a pig to get too,its behind the main pcb
hi,yeah it has sub board at the back, capacitor for fan as well, sometings definitly shorting..thanks for the replies will have a look at those things
rgrds phil
hi, still no joy with this problem going back tomorrow...one of the fuse blew today and it was the live fuse instead of the both left a nasty scource aswell.. i checked the amps only drawing .5 amp....any ideas?
rgds phil
this maybe a long shot,is the indoor fan blade clean?Quote:
Originally Posted by philjd26
hi, just to let you know i think i got this thing sorted, countinued to go bang every day or so, i tried lowerring the fan speed,that was 2 weeks ago and still running so i imagine a relay is bunched on the pcb or something..
cheers phil
Hi,Quote:
Originally Posted by philjd26
what is the fuse rating. It should be higher than the motor rated current. Even you say it is 0.5 Amps , I feel it is exceeding the rate of the fuse.What about the rpm. Is that correct?;)