20 Most Recent Hitachi EC12 Portable Electric 2hp Air Compressor, Oil Lubricated - Page 7 Questions & Answers

I want to be sure we are talking about the same. Most likely your compressor has only one safety valve however since it can come with two I want to be sure which one you are referring to. The first will be located on the bottom or back side of the pressure switch. The second if installed is located on the tank check valve. I assume you are referring to the one on the switch correct?

If this is the case then please let me know exactly where this cap was located. You stated it was located under the relief/safety valve but it's not part of the valve correct?
Is it part of the manifold attached to the bottom/backside of the switch?
Although the pic is a generic switch it will help if you can tell me if the location A or B is where you think it came from.
The black line is there because a lot of switches have a flat bottom and some have a small cap to seal off an additional port/ports.
Most switches are not produced by the compressor manufacturer. Because of this many are used on a number of different models as well as a variety of compressor manufacturers. To accommodate as many as they can switches sometimes have ports that are sealed off using a cap or large allen head plug when the compressor does not utilize all the options available on the switch. This is most likely what the cap is for.
Still I want to be sure so again take a look at the pic and if possible give me a general location.
I'll be waiting your reply.












http://www.hitachipowertools.com/product/files/pneumatics/compressors/EC12_E4_BD.pdf

is the tank full of air, if it is, the regulator(pressure switch) will not allow it to start

bleed of excess pressure and see what happens

Normally you can find the setting instructions on the underside of the switch cover.
In almost all compressor switches you will find two adjustment screws. One is for the "Cut-in/Cut-out" or "Cut-on/Cut-off" psi. The other for "Cut-out" psi only. If there is no label the easiest way to tell the difference is by the springs. The "Cut-in/Cut-out" is the larger of the two springs.

Start by turning the smaller or "Cut-out" screw counter-clockwise. This will decrease the Cut-out psi. I would say to back it off 1 1/2 or 2 turns. Now run the compressor and check where your max psi is. Your target is 105psi if your present "Cut-in" psi is 80psi. Once you have that setting at 105psi, move to the larger screw or "Cut-in/Cut-out" adjustment. Turn the screw clock-wise making 1/4 turns adjustment until you reach the 100/125 psi.

By blow off I assume you mean the unloader valve. There really isn't any setting for the unloader because it's built in to the valve itself.

Since there are some variations for this switch please let me know and I'll explain how to make the adjustments for your type.
Or if you are unclear about anything here just let me know and I will be happy to help you out.
Hope this helps.

1.Check the motor first. You can readily see if it's
burned or not. Run a megger test on the motor.
Test run the motor without the compressor.
2. If, it does not run, have it checked at the motor
rewinding shop.
3. Once it is okey, remount the motor, and start it up.

I believe you have a faulty pressure switch. The black hose reports to the switch what the pressure is and either starts or stops the compressor through the switch. Air is bleeding out of the hose ...causing short cycling ... for some reason. Fix the leak - fix your problem

Thanks for using FixYa.com

positive comments always welcome

a

Your power cord should go into a plastic box (the pressure switch). Your on/off switch is probably on the same box. Unplug the unit, remove the cover of the switch, and you will find one or two adjusting screws. The main adjustment is usually a silver or gold screw (NOT the terminals with the wires on them).
Turn clockwise to increase pressure, counterclockwise to decrease pressure.
If the differential (the difference between cut-in and cut-out) needs adjusted, there is sometimes a second (usually plastic) adjusting screw behind and to the left of the main screw to adjust the cut-in without adjusting the cut-out.
You won't get the differential any tighter than maybe 25-30 PSI.
Test run while bleeding off a little air, and see if further adjustment is necessary. If so, you can adjust with the power plugged in IF YOU ARE CAREFUL - the wire terminals in the pressure switch are exposed and they will have voltage that can zap you.
Make sure you don't overpressurize (run higher than rated pressure) the unit, or your motor will overload, or the safety valve will pop off.
Let me know if this helps!

is there oil in crank case buddy

either by the sight glass half full or by the dipstick touching the line on the dipstick (fillerplug) get back to me if need more info

to repair this problem (a) the pressure switch is not working,(b) check valve or non return valve sticking(stripe down repair and refit)

could be a piston ring problem blown gasket sticking valves what did you over haul get back to me

You have to manually adjust the pressure regulator. Make sure drain is completely closed. The one thats on the bottom of the tanks

hi mate to adjust the pressure you need to take the cover off the pressure switch by unscrewing a little screw in the middle then it will pull off then inside you will find a screw /a bolt with sighns next to it saying + and - unscrew to decrease pressure screw in to increase pressure the pressure guage just tells you how much air is in the tank and when the compressor turns off it will bleed the air off in the system just incase you didnt know

It sounds like your pressure switch has a bad diaphragm. I'd replace the switch.
--W/D--

Hi
Are you using fresh gasoline?
All engines need AIR, FUEL, SPARK to work.
Do a systematic check on all three, if in doubt take to a Technician to investigate.

look in the box where the wires go in and see if ther is an ajustment screw if n ot replace that box it is the pressure switch

NO,NOT FOR MINE,REMOVE TANK FILL WITH WATER AND TAKE TO A WELDING SHOP.THATIS THE BEST AND SAFEST WAY

make sure your plugged directly to an outlet. no extension chords

tighten pop off valve colar
check oil / might be over filled

well make sure air pressure is not too high. if not just replace it any air supply house carries them

Do you have the facility to top up the oil level on the compressor

If so you may find that the low oil sensor is kicking in and trying to prevent you from running the machine dry.

It sounds like you have trouble with your pressure regulator. Make sure that the knob for the regulator is turned clockwise to increase pressure. If this doesn't work, you may need to replace the regulator.