Only cuts for 3 seconds, device still on

This could possibly be, you have some water from condensation buildup inside the tank, liquid does not compress. Before this next step make sure the tank is to 0 psi! Now, there should be a relief valve Wingnut on the bottom. Loosen the wing nut and drain as needed. Then retighten the wingnut (Do not overtighten). Plug the compressor in and try it. My second suggestion is, the psi adjustment pressure knob could be faulty replace as needed!

If you start it and it runs for 5 minutes or so and stops, then it is building enough pressure to operate normally. Check the gauges and you should see about 100 or so on the gauge. If it does not shut off then there is something wrong with the unit and it wont build pressure. This could be a valve that is stuck or a gasket that failed. If you have pressure then you need to check the regulator on the unit. Where the hose connects look for a knob that increases the pressure, there should be a gauge next to it and that shows what the regulated pressure is. Turn the knob to increase the pressure. Last but not least, most sprinkler systems take a lot of air to clear the lines. Some small compressors cannot do it. You did not say what the item is that you a clearing out and you did not say what the compressor is. Therefore it is hard to tell.

Oil free pumps do tend to blow the piston ring (not too expensive) available at searsparts.com. Remove covers to pump and manually turn crank until piston is at top and look at the condition of the cylinder neer top, If it looks scratched, order cylinder kit with piston ring. If it looks good and shiney, could be the valve plate in the head. There are reed valves that tend to break. Run pump however with covers removed and check with soapy water for air leaks and repair as needed (air leaks under the cover will prevent unit from filling). Good luck

You have to have a leak some where other than you compresser. check the lines and fitting s to you air tools.

Sounds like the unloader valve is not working properly. The unloader typically is at the end of a tube going to the pressure switch. The unloader is tripped when the pressure switch cuts off. The purpose of the unloader is to bleed the pressure from the cylinder when the compressor cuts off so the next time the compressor cuts on it will be starting in an unloaded condition.
when the compressor cuts off you should hear a discharge of air for about 3 to 5 seconds if the switch is working properly. The unloader can be adjusted if necessary by loosening the jam nuts and adjusting the unloader towards the lever on the pressure switch.

It looks like there might be a knob which sets the max air pressure coming from the compressor. If there is one, this may have been turned down.

There are usually 3 pressure settings on an electric compressor. Compressor max, pressure switch cut on, and pressure switch cut off.

The SkyBox operates with two individual systems. The dispenser assembly, the LED indicators and the circulating fan operate on a low voltage circuit. The circulating fan runs anytime the SkyBox is plugged in.

The cooling system operates on 120vac. The cold control inside the beverage compartment is an on demand switch that sends 120vac to the compressor when cooling is needed. There are no parts available for the compressor, so if it determined that power is reaching the compressor, the windings are ok, a 3 in1 hard start kit (Supco URCO210) can be installed by a qualified service technician.

compressor will not build pressure

1)Let your unit pump up.
2)Turn it off.
3)Find the supply line from the pump to the tank.
4)Remove the supply line from the pump head.
5a)If you hear air coming from the tank you have a bad check valve.
5b)If you do not hear air coming from the tank, you have a leaky
pressure switch.

-If both compressor and fan motor starts and stop, thermostat is the defect.
- If only the compressor check for your outlet no sign of discoloration, check the voltage if normal, check the defective overload protector of the compressor it its external, or compressor itself is defective