View Single Post
  #5   Report Post  
Posted to rec.crafts.metalworking
Don Foreman
 
Posts: n/a
Default Repair my Emglo AM78-HV4V air compressor

On Sun, 15 Jan 2006 15:53:43 -0800, "Mike S." wrote:

We were using our Emglo and shut it down for a lunch break. When we came
back and tried to start it again all we got was a load electrical hum and
sometimes it would pop our 15 amp breaker.

I pulled the compressor/electric motor unit loose from the rest of the
compressor so I could get to its guts. When I turned the fan blade by hand
(it turned very easily) I could hear the compressor piston working. I even
connected the AC power back up but still heard the hum. When I gave the fan
a twist the motor started running the compressor. However, the motor won't
start the compressor on its own.

I tried a quick test of the start-up capacitor with my multimeter and it
appears to be OK. It slowly climbs in ohms until infinity. Reversed the
probes and it does the same thing. Sounds like the capacitor is OK to me.

I wanted to pull the electric motor loose from the case so I could see the
brushes and rotor. I removed all the mounting screws from everything I
could see, but I can't seem to pull the unit apart to get to the motor.
Everything is loose and I can twist the case a few degrees, but I can't pull
it apart.

Anybody know how I can get the motor out so I can look at its guts. Any
help is appreciated. Pretend I'm a dunce and be pretty specific.

Thanks,
Mike


There aren't any brushes in an AC induction motor.

Disconnect the start cap and check both leads for continuity to the
plug or mains connection (with it unplugged, of course!) You should
see continuity from both cap connections to both line connections,
though the (low) resistances will be different. If one of them
check open, there's your problem.

The most likely cause is a failed centrifugal start switch.

Hope someone can tell you how to get the motor loose.

Most capacitor start motors have t