Thermal overload protector tripped

[EdT]

I have an older 2HP compressor that is my portable, general purpose compressor when I don't feel like running miles of hose from my big compressor. Today I was working it pretty hard. It was running about 75% of the time and it was in the mid 80's. So, warm, but not stifling. Well, eventually the thermal overload popped and it stopped. I felt the motor and I'd guess it was about 140F on the outside. No biggy, I'll just wait for it to cool off so I can reset the little red button on the end bell. It's cooled of to ambient now after a few hours and the little button won't reset. It does not move at all when pressed. The motor is a CENTURY 164079 or an AO SMITH B381. Any suggestions? Is this a "one shot" overload device?

 

[PT Doc]

Seems like it was run quite hard but the overload if functioning properly should have tripped in time to save the motor. I was surprised when I read that an 80 gal 2stage compressor is rated for continuous duty is recommended for 6 startups per hour. Seems like a contradiction of the definition.

I would all the manufacturer on Monday before you go much further. It might be quite simple but I would save thought the button would reset itself. Maybe try unplugging it and plugging into different circuit. Maybe something needs to be unloaded. Good lick and post back the resolution or solution.

 

[KenC]

It's cooled of to ambient now after a few hours and the little button won't reset. It does not move at all when pressed. The motor is a CENTURY 164079 or an AO SMITH B381. Any suggestions? Is this a "one shot" overload device?

Most of those don't move much, if at all, when reset. It will require a fairly firm push and there should be an audible click if/when it resets.

It's possible for the little disk to deform and fail to reset. If so, they're easy to replace.

 

[Gary S]

I would expect that if you take the motor to an electric motor repair shop, they would either have a new thermal overload in stock or be able to get you one quite fast.