fima compressor wont start

[oilcooled :)]

i have to fix a compressor for a fella, it wouldnt kick in once the air emptied out to such a level, got that sorted, and all was sound. went out the other day to start it and talking about a waste of time, kept tripping its own breaker, had to take the gaurd off an crank it with a ratchet while pulling the button, after half an hour got the bitch going, got up to 3/4 cut out pressure and it tripped itself, reset it and let the air out, it tried to kick itself in at the lower pressure where it should, made a good effort then tripped itself again. is it the cold ? its a single phase, think its a 300 litre tank, belt driven obviosly. .. we have a 200 litre new sip thats hard started but not that bad.

 

[slimjim]

it could be the cold, making the oil really thick, it could also be the starter capacitor

 

[oilcooled :)]

isnt a capacitor basically a battery?

 

[slimjim]

isnt a capacitor basically a battery?

sort of

why?

 

[scarecrow]

there is motor run and motor start capacitors there are probably more like a booster
pulled the motor off and take it to an electrician to check it out

 

[oilcooled :)]

well i presume the capacitor is to boost the power on start up. can i not short wire out the trip?

 

[slimjim]

well i presume the capacitor is to boost the power on start up. can i not short wire out the trip?

it boosts the torque and helps stop the motor tripping the fuse on startup

 

[oilcooled :)]

i meant leave the capacitor alone, and short the trip

 

[piman]

Hello Oilcooled,

the capacitor is not a booster, but alters the current\voltage phase relationship, this is used to cause a rotating field (which you naturally get with three phase) to get the motor turning. It will start without if you spin the motor, which you did.

I think you need to check how tight the compressor is, supply voltage (when running) and running current? A megger check would also be worth doing if there's one available?

Alec

 

[slimjim]

Having said that, we are having the same problem with a few of our compressors and its the cold