Board logo

Electric motor help please
jacko - 16/7/17 at 08:44 PM

Hi all
My son has a compressor and the motor has started to blow fuses
if you put a new 13a fuse in the plug the motor starts then blows the fuse
anyone know what could be wrong with it
thanks
jacko


r1_pete - 16/7/17 at 08:53 PM

Sounds like either the run windings are shorting, or the switch which changes over from start to run is shorting.

Depending on the size I'm guessing sub 3hp, it'll probably be cheaper to replace than fix, Machine Mart do a range of motors.


rf900rush - 16/7/17 at 08:53 PM

I have had a couple of small compressors do similar.

Check the Start capacitor wires. Mine broke from vibration.

This stops the motor from starting the blows the fuse.

Worth a check.


obfripper - 16/7/17 at 08:57 PM

Only when there is a partial charge of air in the tank?
This would be either the pressure release valve that is in the switch unit or the non return valve in the pipe from the compressor pump, as too much current is required to start the motor with 100psi already in the cylinder.
If the stop switch is pushed in while the compressor is running, the release of pressure should be clearly heard if working correctly and stop within half a second.

If it is with no charge in the tank, as above it could be a capacitor fault or a run switch fault causing the motor to run below rated speed and draw too much current.

Dave


jacko - 17/7/17 at 06:44 PM

I talked to someone that knows a bit about motors and he says it could be one of two things
1 the switch that switches the winding's from start to run
or 2 the running winding's that are earthing out
He says the best thing to do is have it checked out at a motor repair company
so that's what i will do
Thank's for your help
Jacko