Ridgid compressor unloader closes too quickly on restart under load compressor stalls

by Jeff Griffin
(Colusa, Ca.)

I have a 1.8 hp rigid stack with a brand new pressure switch that works great with no pressure in tank BUT stalls out on restart under load.

I've adjusted the unloader valve and it is working but closes too quickly upon restart and motor stalls out.

It has some kind of protection in the switch to keep from tripping the breaker so it tries to restart every few minutes.

When I unhook the unloader line it start and runs fine.

I have a new pressure switch and have replaced both starters (capacitors)on the motor.

It is on a 20amp circuit BUT is on a 100' extension cord that is 14 guage wire.

Jeff, I don't know what switch you are using, if it has an internal or external unloader.

Typically, when the unloader operates, it takes only a fraction of a second to unload the air over the piston to allow an easier restart, so I suspect that your unload is fine.

Try moving your air compressor so that you can plug it directly into a socket without the extension cord. If that resolved the restart under load problem, either dump the cord, or move to a 12 gauge wire but no longer than 25'.

If you need the air farther away from the power supply than that, buy a longer air hose, and power the compressor directly from the wall socket.

The longer hose will reduce the air flow, yet no air tool will self-destruct by not getting enough air supply. Your compressor motor will self-destruct if you continue to underpower it, which is what I suspect you are doing by using the long cord, and particularly, if the compressor is cold when you try to restart it.

I would appreciate hearing your findings as a comment here.



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