Hi,

I just got an Ingersol Rand compressor from the "FREE" pile
down the street, it’s obviously been neglected and abused but it does
run. I am only going to use it occasionally for topping up the car
tires and bike tires, perhaps a blow gun for cleaning stuff.

Like I said it is in rough condition, I have begun to adjust the
pressure switch. (A)Big spring = cut out, (B)small spring =
differential and it’s working OK, what is the third bleeder valve[C]?
When the contacts open a lever depresses a small brass valve that
bleeds air, this is connected to the manifold under the pressure
switch. Should this bleed as soon as the limit is hit or delay until
the lower or differential pressure is about to kick back in? It looks
like either the valve can be raised/lowered by it’s mounting nuts and
there is a plunger on the armature of the switch that screws up/down
in a plastic thread.
Photo he http://www.freewebs.com/bozonia/hp.htm

Staring at the pressure switch some more I see the spring I labled
"B" does nothing. there is a screw post with a pin thru it
on which rests a flat washer, a smaller washer then the spring, then
a cup washer and the nut. the lever from the contacts is above the
washers and never makes contact with the spring or other parts. Looks
like someone lost some parts!!

If anyone has a similar switch and can take a picture and either post
it or e-mail to kd006(at)yahoo.com I just may be able to figure this
out.

Thanks
Kristin