What's new
What's new

Weird click in motor trips breaker

Joined
Mar 30, 2020
I just picked up a used drill press from a neighbor and it does this weird thing.
It starts up just fine and operates totally normally. After you switch it off as the motor is slowing down, there is an audible click and it trips the breaker every time. He told me about it before I got the drill press from him and he just pulls the plug after he flips the switch off. Anyone have any ideas what could cause this? Also, how does it blow the breaker if the switch is off? I can continue to pull the cord but would love to know the cause.

Before anyone asks. It's 1.5 hp 110v

Thanks in advance,
Aaron
 
Aaron,

Welcome to the forum.

That 'click' sound is the centrifugal switch closing as the motor speed winds down. There should be no power applied at that point if you have shut the machine down, which would preclude any ability to trip a breaker. I would say there is something wired incorrectly, either the motor/cap leads or the ON/OFF switch.

Stuart

Stuart
 
sounds like a cheap single pole switch, possibly only breaking the neutral. Or a fried 2 pole where the hot contacts welded shut.

As has been said, it's wired incorrectly. Possibly with a cheap or defective switch. If you don't address it, it will probably soon erode the contacts on the centrifugal switch in the motor.

smt
 
Thanks guys! I hadn’t jumped into it but I assumed that if there was something causing the breaker to trip then it had to be an issue with the switch. I’ll replace the switch and check all the other connections.

I’ll post an update soon.
 
So there was a stuck contact in the switch. Cleaned the contact and it’s working as it should now and I’ll order a new switch for extra piece of mind. With that being said, the motor still makes a single click as it is coming to a stop after power is cut. You guys think that’s something to be worried about?
 
A single click is fine, that is the centrifugal switch working.

If the notor jerks, its because voltage is stored in the start cap and when the switch reconnects the energy is dumped back into the motor. A resistor across the start cap will fix that issue.
 
Thanks! Yeah no jerk in the motor. Just a click. Super happy my problem was just a bad switch! Thanks for the help everyone!
 








 
Back
Top