ComAir Kellogg only works when reset is held in .

by Doyce Farris
(Corbin, KY)

I have a Comair Kellog model B335UB sn V9J6186PFZI air compressor. It has a Baldor Industrial 5hp 3 Phase motor. It had been working fine for years. The compressor would not come on this morning.

I found that I could hold in the reset button on the Furnas Controller model PN XF-5-230 and the compressor will run but it will not shut off when it gets pressure built up.

I think it could be the Pressure switch but I do not know how to check. I would also like to know if you have the parts for this. Thanks Doyce

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Bill says...

Hello Doyce.

It has been my experience that when a compressor builds pressure to the normal cut out pressure level and doesn't stop, that it is the pressure switch that is at fault.

It is the pressure switch that senses the pressure in the compressor tank.

When that pressure falls to the preset level of that switch, it trips, and power flows to the motor.

As the motor runs, the pressure in the tank rises, until it reaches the cut out pressure level. At this point the pressure switch should trip off, cutting power to the motor.

In pressure continues to build in the tank as the pressure level bypasses the normal cut out, it signifies that the pressure switch has failed.

Replace it. Fast! It's dangerous to run an air compressor that will not shut off.

Cheers,

Bill