My Sanborn 5hp 90lbs compressor will not start up, new out of the crate.

by Greg
(Great bend, ks)

I purchased a new Sanborn compressor  (5hp 90lbs 240v) and had an electrician come and do the electrical hookups.

There’s juice everywhere there should be right up to the motor, and it will not start.

Newer Sanborn 5 HP air compressor
Newer Sanborn 5 HP air compressor

Tried to jump the thermal cut-out switch thinking it was bad. No luck. Any suggestions?
Greg, if absolutely nothing happens when you power up the compressor, and if the power is getting to the motor circuit for sure, then I would think, it were mine, that the start capacitor has failed, and is preventing even any flow of power to the motor.

Sometimes start caps fail and the motor still gets juice, tries to start, and pops a breaker or heats up and goes off on thermal overload.

If you have power on both sides of the thermal switch, then that’s not the problem. Jumping it won’t help.

A start cap that has failed open prevents any power from getting through.

I would think it’s that or the motor itself is pooched.