Hitachi EC12 Portable Electric 2hp Air Compressor, Oil Lubricated - Answered Questions & Fixed issues

if you replaced capacitor exactly like it was remove and no wires switched you have a bad motor.

Check the circuit breaker reset located under the shroud above the dipstick. If the unit hums but won't turn, first drain the air completely and then try it (If it starts, your problem is most likely the check valve located on the tank) 2) Unplug it and carefully use a thin screwdriver to turn the fan blade - if it spins and is not bound then try it again. If it still doesn't start I would look at the start capacitor located under the shroud

The EC12 holds 8 ounces I recommend synthetic

The head pressure is released thru the needle unloader valve at the pressure switch. Notice a 1/4 inch plastic tube (or metal) running from the intank check valve to the pressure switch. After pressure switch reaches set pressure a small tang moves up and presses on the needle valve releasing the pressure. Only a small amount of air will be released. If however air continues to escape from the needle valve, then the check valve is bad.

The EC12 actually draws approximately 15.5 amps when starting, so you are best served to use without extention cord on a 20 amp circuit. One thing that will improve operation, is to use 5w-50 full sinthetic oil. Fill to notch in dipstick. If possible change your overload switch to a 20 amp. It is currently a 15 amp. (cause right there for continual overload). I unplugged my reset button and added a piece of #12 coated wire as a jumper (do this at your own risk), but I've been fine for three years now. #12 wire fits right into the clips that attach to the reset button. Good luck.

It sounds like the air pressure assembly unit is not reading the pressure drop. some of these units have adjustments under the covers and be reset.

Put in the best grade oil for small high RPM engines

The starter capacitor is on the electric motor and is a round shape

This problem is caused by either the starter capacitor or the in-tank check valve. Ez to check. With no air in tank, start compressor; if motor hums or has difficulty suspect capacitor. If motor starts, partially fill tank and unplug the power. Check for air leaking at the pressure switch or air coming out of the air inlet (remove the air filter). If air leaking, replace check valve. If no air leaking, again let out all the from the tank and connect power. Allow the compressor to fill and shut-off. After the compressor fills, again listen for air leaking from the pressure switch unloader valve. If air continues to leak from unloader, replace the check valve. Good luck

Does compressor have oil in reservoir? If not, add oil. Also the switch may have gone bad.

look for a bad start capacitor.

possibly a bad capacitor or motor

Find the pressure switch. Remove the cover and loosen the spring loaded nuts on-till the switch opens. Readjust for the pressure you need. Keep it below the amp rating on the motor to keep the breaker from tripping. (RLA or FLA).

It sounds like your car ran out of oil and the engine seized

I would not worry. Drain the tank completely, and check the oil in the compressor, top off if necessary. Watch it for the first cycle.

Most P/C compressors shut off at 150psi. If the pressure switch is bad, the pressure will rise until the safety pops. If the safety is not opening, then most likely the cylinder / piston ring is worn to the point that pressure will not increase past safety range (cylinder could be scratched near top ). If cylinder and piston are ok, then air is leaking somewhere (check all joints with soapy water). Good luck

There should be a pressure switch adjustment under the cover of the switch remove the cover and reset.

what is the working pressure bud

The regulator sounds like it is cranked closed. Try slowly operating the adjusting knob in the opposite direction. As the valve moves, you should see the pressure rise on your gauge (it probably does work).
Hope this helps....now go make something!
Best regards, --W/D--

With a 110, you do not need a Capacitor