# repairing air compressors



## Wildie (Jul 23, 2008)

drewhart said:


> i have a porter cable pancake air compressor with an emglo oil engine. i have to turn it on and then off right away about thirty times before it will run. it just hums otherwise. if i turn it on and leave it on too early the compressors internal circuit breaker or the breaker in the box will trip. i have been told it coulde be a weak compacitor or a bad start valve. what do you think i should do? are these hard things to replace?
> 
> actualy it may not be a porter cable one. its red and the pancake is on its side. there is a square cage around it with a handle in the middle. i bought it from a guy and i forgot what kind it is.


 Some motors have two windings. A start winding and a run winding!
A centrifugal switch transfers the power from the start winding to the run winding.
These centrifugal switches are prone to 'arc' damage and carbon buildup.
When the motor is turned off, the 'break' contacts must close to allow current to flow through the start winding. 
If the 'make' contact is still closed to the 'run' winding it will cause the over current protection to function.
Repair of these can be tricky, as the contact 'gap' is set using a 'feeler' guage.
If you have good mechanical skills, and the necessary tools, you may be able to repair it yourself!


----------



## drewhart (Jul 13, 2008)

man that sounds tricky. so basically i need a new centrifigal switch, and when installing it, it needs to be placed in the right in the right position (gap)?? where is the centrifigal switch? and where can i get a feeler gauge? i bought this compressor for $25 and i have another one (emglo twin tank) that works good, so i am willing to experiment.


----------



## Wildie (Jul 23, 2008)

drewhart said:


> man that sounds tricky. so basically i need a new centrifigal switch, and when installing it, it needs to be placed in the right in the right position (gap)?? where is the centrifigal switch? and where can i get a feeler gauge? i bought this compressor for $25 and i have another one (emglo twin tank) that works good, so i am willing to experiment.


 Part of the switch is located on the motor shaft, and has a spring activated collar. When the motor is up to speed, the collar moves toward the contact armiture.
The contacts are mounted on the end 'bell' on an insulated card. This card has terminals to accommodate the power wires and terminals for the winding connections.
Sometimes the contacts can be cleaned with a metal finger nail file. Then the contact mounting can be 'bent' to allow for the missing contact surface, that was filed off.
Motor shops don't usually bother with trying to repair the switch. The usually replace with a new one!


----------



## drewhart (Jul 13, 2008)

do you have a link to any diagrams or pictures of this engine?


----------



## Wildie (Jul 23, 2008)

drewhart said:


> do you have a link to any diagrams or pictures of this engine?


 i made a Google search, with limited results. I did come across this site 

http://www.leeson.com/servicesupport/troubleshooting.htm
 
It may be of some assistance!


----------

