Sears compressor runs till it gets about 15 psi. then slows down and trips off.

by glenn
(yorktown va.)

Sears 4hp single phase 115v. Sears compressor runs till it gets about 15 psi. then slows down and trips off.

________________________

If it hit 15 PSI and tripped a breaker, it might be the pressure switch, Glenn, but let’s look beyond that.

Since the motor is slowing, I believe it is reacting to an increasing load.

That load could be the back pressure from the steadily filling tank and the increasing tank pressure against which the pump must drive.

If could be a bad check valve too, could be that the motor hasn’t got the poop left in it to pump air past 15 PSI back pressure.

Or it could be something in the pump itself.

Is the problem repeatable? Do you re-set (what is being reset, the thermal overload on the motor?) and exactly the same thing happens again?

Another consideration is the run capacitor is weakening or failing, assuming that your are not using an extension cord that is choking the power supply to the compressor.

Any chance you could upload a photo or two and more details about the compressor actions would help.

Keep us posted, if you would.

New comment? New question? Please add it here along with photos to help others help you with your compressor and equipment problem!