Blows breaker only when starting with partia pressure in tank.

by Roger
(Bremerton WA)

Starts fine with empty tank.

It kind of chugs a little like starting your truck in second gear then pops breaker if any pressure in tank.
I have disconnected hose to unload valve so there shouldn't be any back pressure.
If started on empty tank it runs perfect to 120 psi so I think motor is fine.
Take cover off and motor and piston turn with zero resistance.
I think it is starter caps but they tested good at motor shop.
Please empty the tank, start the compressor, monitor the unloader valve, and comment here as to whether it works or not.


Comments for Blows breaker only when starting with partia pressure in tank.

Click here to add your own comments

May 09, 2014
Craftsman 26 gallon Air Compressor
by: GP

I have a 2 year old Craftsman 26 gallon air compressor with a 5 hp 120v electric motor. I have used it 4 times over the past 2 years to pump tires on either of my 3 cars.

It say in the shed (protected from rain and snow) all winter. When I ran the 30 foot extension cord from the house to the shed and plugged in the compressor it runs slow, does not pump very much air pressure in the tank (shows zero on the guage)and trips the 20amp breaker.

I have tried three different extension cords, and the result is the same each time.

The 26 gallon air tank is empty.
GP, while your compressor may say "5 hp 120v electric motor" I assure you that you cannot power a 5 HP electric motor properly with 120 volts.

If your motor is really 120 volts, then it sounds to me like your start and run capacitors are failing or your extension cord is to small a gauge.


Jan 03, 2014
hausfeld Campbell WL604004AJ with same problem
by: Bob

Ditto for me.

Compressor works fine with zero pressure. Will go up to 120 and the unloader valve will let out a satisfying pssffftt.

It will try to pressurize again at 80-90 and chug and then trip the breaker.

Besides the unloader valve, what else could cause this.

No extension cords,
new 20 amp fuse



Jan 02, 2014
Rigid Twin blows breaker
by: DanielLongo

This is exactly the scenerio I am facing. The compressor struggles then quits as it blows the breaker when the tank has full or partial pressure. Air has to be dumped completely to zero in order for it to start and then it works fine up to 150psi. I would very much appreciate if an answer is found that it be posted. I will do the same if I reach the fix first.

See the troubleshooting section for pages about reasons why an air compressor will not restart or start. After doing the checks, if the problem persists, start a new thread so your question and responses can be moved to the correct forum, in this case, Rigid compressor forum.

Dec 30, 2013
by: Roger Anderson

Emptied tank. Started perfect and ran fine to 120psi and unloader valve worked when it stopped. Did again and stopped at 60psi with unloader working. Then chugged and popped breaker when I tried to restart
Anything new in power supply. Using extension cord or power bar? If so, don't.

What is normal cut in and cut out? Cut out is not likely 60 PSI. If it stopped there, then I'd suspect the pressure switch is failing.

I'd check the start capacitor next. How to is on this site.

Click here to add your own comments

Add your own question or comment. It's easy to do. How? Simply click here to return to Compressor Blows Breaker.