the pressure switch doesnt kick off at the max pressure
I put a new pressure switch on my compressor, it still goes past the max pressure. so i have to switch the breaker off. when it does eventually shut off the motor hums and doesnt want to start.
Matt, if you put a new pressure switch on your air compressor and the pressure in the tank exceeds the normal cut out pressure, a few things come to mind.
When you acquired the replacement, were the set points the same as the old pressure switch, and if not, did you adjust the new switch settings to mirror the old?
Or, the pressure switch points typically open when the diaphragm in the base of the switch experiences the set point pressure. If the set points are not opening, then you either have a bum switch, or the wiring is incorrect.
When you installed the new switch, did you reconnect the unloader valve? A non-working unloader could be the reason the compressor will not start on it's own if there is pressure in the tank.
Pressure relief switch
by Fred Kaier
When my SEARS compressor shuts off, air is leaking from the pressure control switch. (brass fitting with an actuator pin on the bottom of the square D switch box) The only part # I can find on the switch is CAC-4336.what is the replacement part and where can I get it?
While air may be leaking from the unloader valve on your pressure switch, I don't think it's either the unloader valve or the pressure switch that is your problem.
There's a check valve in the line from the head to the tank, and it's purpose is to keep the air in the tank once the compressor unloads. If that leaks, all of the air in your tank will bleed out the unloader valve. Here's more info on this issue.