Overloads Motor

by Oscar
(Farmingdale NY)

My Cambell Hausfeld 2 HP air compressor is set to go off at 180 psi.

But as the air builds up to 100 psi the motor starts slowing down and the belt starts squeaking.

But the motor some how manages push slowly past 100 psi and then starts running well till the cut off pressure is reached.

All this started recently when I changed the pressure switch. Can you tell we what is wrong.
Thanks.
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Bill says...

Oscar... this is a weird one.

First question; do you hear the psssshhht of the compressor unloading when the pressure in the tank finally reaches cut out pressure level? In other words, does it unload properly? Probably does, but I'm curious.

The belt starts squeaking, I think, because the motor is trying to rotate the motor sheave at a constant pressure, the compressor sheave is binding or something is slowing it down, and that is causing the belt to squeal on the compressor sheave.

Therefore, something is logging down your motor in the affected pressure range. I am at a loss to figure out what might be doing this within the pressure range you describe, and changing the pressure switch shouldn't have anything to do with any of the symptoms you describe.

Gosh, wish I could offer more. Anyone else?

Cheers,

Bill