Regulator will not shut off the compressor !

by David

I have a old compressor M/D 32396 stage CCW, the regulator will not shut off the compressor it keeps running until the pop off vale go's off what part do I need to buy thank D Bond

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Bill answers...

Hi David, and thanks for writing in.

Just to make sure we are both "on the same page", the regulator on an air compressor is used to set a specific pressure level for air tools downstream from it. It has nothing to do with turning on or shutting off your air compressor.

It is the pressure switch that has the job of turning your air compressor on when the pressure in the tank falls to the cut-in pressure level, and it's the pressure switch that shuts the compressor off when the pressure in the tank reaches the high pressure cut-out level.

Inside the pressure switch there are contactors that open and close in response to the pressure in the system.

When the pressure falls to the cut-in level, the pressure switch shifts, and the contacts close, allowing electricity to flow to the motor so it will start.

When high pressure is reached, the contactors open, and the electricity to the motor is stopped, as does the motor and the compressor.

What I think is happening with your compressor system is that the pressure switch has malfunctioned, and even though the pressure in the system reaches the cut-out pressure, the pressure switch doesn't shift, and the motor keeps running.

The PRV (pressure relief valve) is there for just this circumstance, and thank goodness it is, as otherwise, the pressure in the system would reach unsafe levels.

In your shoes, I wouldn't use my compressor again until I got the switch replaced. It's not too hard to do, but even if you aren't up to doing it, get it fixed.

Cheers,

Bill