20 Most Recent Hitachi EC12 Portable Electric 2hp Air Compressor, Oil Lubricated - Page 5 Questions & Answers

One thing mine does, If it is plugged into a 15 amp circuit , it will do the same thing. It needs a 20 amp circuit to run, the start up motor on those things draw 16+ amps, and then run on 13. If it is cold, full of air, it won't run, if it has a cord of any length, forget it, It needs a big cord, 20 amp circuit, or no air in the tank and be warm. In the winter time we all had our compressors in the bathroom with the heat on, I though it was for us to warm up in, but it was for the compressors. I thought mine was the only that did it.

i assume your are talking about the pressure regulator. if it won't adjust to raise and lower the outlet pressure it is broke. you will have to replace it with an in kind type.

As you may have noticed, there is no reset button listed in the parts breakdown. If you have been experiencing unexpected shut-down when the unit is hot you probably have one of the ec12s with a thermal protector incorporated with-in the winding of the motor. To prevent shutdown do not use extension cord or power your compressor with a generator. Test your unit with an amp meter to make sure that it is working with specifications. If you have other questions please post again. Good luck

how big is the compressor? if its only say 3 cubic foot a minuet that is at free air pressure not at say 8 bar,,,at 8 bar it would only be 0.375 cubic foot,, check to see how much air in cubic feet per minuet and at what pressure your tools need to work on
if they say 5 cubic feet at 8 bar and the compressor is only 3 cubic feet at 8 bar the tool will only run for a very short time before the compressor air tank has run out of air and the compressor cant keep up with the demand from the tool
the bigger the compressor and the bigger the air tank the better some times,,,for a hammer tool you need 8 cubic foot at 10 bar
thats a big compressor!! or a small one for only a short burst of time,,, in short,,,all ways go for a big un? compressor that is!!
i hope this has helped you out

It souds like a sticky "non return valve". See the fix below.
The non return valve is the chrome part with a hex cap adjacent to the upper tank. Remove the cap and make sure the piston moves freely. Slight resistance is ok, but if it sticks your compressor willl continually blow off air.

The check valve or "non return valve", as listed in the Hitachi parts manual is definitely the culprit here, but there is an alternative solution to replacing the entire valve that was actually suggested to me by a Hitachi Tech when I stopped by my local service center to pick up a new non return valve. Obviously, the rubber piston swells and sticks to the point that the spring under the piston can't over come the friction. I removed the piston and carefully reduced its diameter, by hand, with varying grades of wet or dry paper and it now operates perfectly. If one is uncomfortable with such a repair, at least keep it in mind for a quick jobsite fix. I have now been running my repaired compressor for several months without issue.

Sounds like theres either a piece of debris in your pressure switch where the 1/4" line enters it. Or you have debris stuck in your check valve or a bad check valve. Remove the pressure switch line and check valve and try cleaning the valve and the switch where the line was disconnected. with solvent and compressed air. Unfortunitely you'll need someone elses air source.

When the pressure reducer fails, it may leak around the adjuster or it may close as yours has. A temporary fix would be to remove the safety unloader or a tank pressure gauge and install a tee fitting replacing safey or gauge and install a quick fitting for air. You will only have tank pressure available however this is a temp fix untill you replace the pressure reducer. You do not have to replace with factory parts, there are generic parts available at Lowes or similar stores. For factory parts go to www.toolpartsdirect.com. Good luck with your repair and post again if you have other question.

On your next trip to Lowes look for Kobalt air compressor oil in the tool department. It sells for under $3 and works great for normal use. They also have Kobalt synthetic compressor oil for extreme conditions and longer use between oil changes. Sell for about $7. I also used Hitachi synthetic oil #19210b 8oz about $8 but hard to find. Kobalt synthetic costs less and works. Good luck.

I have the same compressor with the same problem. I have temporarily eliminated the thermal reset with a piece of 12 gauge hard wire and it runs just fine. However, I do want to replace it before the warm weather come to the north. I tested the draw at 15.5 amps and the reset was a 17 amp. I am told by someone with superior electrical background that I need to install a 20 amp thermal reset in it's place. I have found that mine runs best when plugged directly into a 20 amp circuit and when using an extention cord I have a 10 guage cord that will carry the load needed to run the EC12. I also have changed to 100% synthetic oil.

I have the same compressor with the same problem. I have temporarily eliminated the thermal reset with a piece of 12 gauge hard wire and it runs just fine. However, I do want to replace it before the warm weather come to the north. I tested the draw at 15.5 amps and the reset was a 17 amp. I am told by someone with superior electrical background that I need to install a 20 amp thermal reset in it's place. I have found that mine runs best when plugged directly into a 20 amp circuit and when using an extention cord I have a 10 guage cord that will carry the load needed to run the EC12. I have also changed to 100% synthetic oil.

I have the same compressor with the same problem. I have temporarily eliminated the thermal reset with a piece of 12 gauge hard wire and it runs just fine. However, I do want to replace it before the warm weather come to the north. I tested the draw at 15.5 amps and the reset was a 17 amp. I am told by someone with superior electrical background that I need to install a 20 amp thermal reset in it's place. I have found that mine runs best when plugged directly into a 20 amp circuit and when using an extention cord I have a 10 guage cord that will carry the load needed to run the EC12.

I have the same compressor with the same problem. I have temporarily eliminated the thermal reset with a piece of 12 gauge hard wire and it runs just fine. However, I do want to replace it before the warm weather come to the north. I tested the draw at 15.5 amps and the reset was a 17 amp. I am told by someone with superior electrical background that I need to install a 20 amp thermal reset in it's place. I have found that mine runs best when plugged directly into a 20 amp circuit and when using an extention cord I have a 10 guage cord that will carry the load needed to run the EC12. I have changed to 100% synthetic oil at the recomended viscosity (5W50 I believe) and it helps in the cold.

I have the same compressor with the same problem. I have temporarily eliminated the thermal reset with a piece of 12 gauge hard wire and it runs just fine. However, I do want to replace it before the warm weather come to the north. I tested the draw at 15.5 amps and the reset was a 17 amp. I am told by someone with superior electrical background that I need to install a 20 amp thermal reset in it's place. I have found that mine runs best when plugged directly into a 20 amp circuit and when using an extention cord I have a 10 guage cord that will carry the load needed to run the EC12.

Compressors have a pressure relief valve, it's in the line between the compressor and the tank usually by the compressor. You should hear a slight hiss as the compressor turns off, this is the relief valve letting the pressure off of the compressor. If you don't hear this hiss you'll need to order a new relief valve from your compressor's manufacture.

You would need 10 times the watts it takes to run electric air compressor,the start up takes a lot more amps to get it going ,then it will level off to the amps,what ever they are.That is the problem,getting it to power up,then it is fine,so you are looking at about 8000 watt gen.

http://www.ereplacementparts.com

You can get parts and diagrams here

http://www.ereplacementparts.com/



Number 63 but go to this site for manual.

http://www.ereplacementparts.com/

I can think of many problems that could cause what you are experiencing.

Are your using a long, small gauge extension cord? Too long and too small of a cord will starve a motor of the power it needs to run properly.

Check the oil level. If the oil is too low the piston can seize to the cylinder. Too much oil can cause excessive pressure in the cylinder, stopping the motor.

There could be a bad bearing. A seized bearing can cause enough resistance to stop the motor.

There are a couple of capacitors on the motor. At least one of them will be used to help start the motor. A motor shop can test them to see if they are both working properly.

Those are the most likely causes. You will need to do some testing to figure out which is causing your problem.

I hope this helps with your repair!

If I understand correctly the safety valve, item #64 on the parts diagram, is opening at 120lbs and not shutting until the tank is drained. If that is the case you most likely have a bad safety valve, part #881-493 which is available from http://www.ereplacementparts.com. The non-return valve is basically a check valve that prohibits the flow of air from the tank back to the cylinder. I hope this helps!