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#26713 - 06/18/03 11:47 PM buzzing breakers  
ga.sparky56  Offline
Joined: Nov 2002
Posts: 558
young harris georgia usa
I have frequently come across breakers that will buzz or hum when a load is applied.

Most frequently,it's associated with an air handler ckt. for heat pumps.The auxillary heat or heat strips as we call them here,may not do this. It's usually when the heat pump/air handler starts.

I've seen it in different makes of loadcenters,different size ckts,have tried moving breakers around with not much improvement.

Now these are almost always ckts. in which the terminations are tight,wire sized properly,everything seems to be done correctly,but sometimes there's a slight buzz no matter what is done.

It seems to drive homeowners nuts,something isn't done right,"you're going to burn my house down" etc.

Any thoughts as to how to avoid/stop this?
Am I doing something wrong?


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#26714 - 06/19/03 12:49 AM Re: buzzing breakers  
amp-man  Offline
Joined: Jun 2001
Posts: 141
Sacto, California US of A

(just couldn't resist...)

Seriously, have you tried installing a new breaker? Maybe the bus clips are a little sloppy, and the surge of power is causing a little rattling.


#26715 - 06/19/03 01:06 AM Re: buzzing breakers  
Bjarney  Offline
Joined: Apr 2002
Posts: 2,527
West-Southern Inner-Northeast ...
An ‘online’ AC millivolt-drop test can be applied to circuit-breaker poles in panelboards, with appropriate caution.

#26716 - 06/19/03 01:11 AM Re: buzzing breakers  
ga.sparky56  Offline
Joined: Nov 2002
Posts: 558
young harris georgia usa
Amp man, I've tried that and other remedies with varying degrees of sucess.

I,ve had this happen in different types of panels. Some I installed and some I didn't.

What puzzles me is everything seems to be in order.


#26717 - 06/19/03 01:13 AM Re: buzzing breakers  
ga.sparky56  Offline
Joined: Nov 2002
Posts: 558
young harris georgia usa
Thanks Bjarney.

#26718 - 06/23/03 03:31 PM Re: buzzing breakers  
JBD  Offline
Joined: Jul 2001
Posts: 599
Found this information on "humming" in electrical equipment at the Square D website.

"...Square D has investigated several instances of reported excessive noise/humming. In most of these instances, loose hardware, wiring, and current transformers have been found to be the cause. In the few instances that this was not the case, the circuit breakers were evaluated and found to have acceptable performance and service life.

No evidence has been found to indicate that operational noise/humming is detrimental to the performance or service life of the circuit breaker..."

#26719 - 06/23/03 07:22 PM Re: buzzing breakers  
ga.sparky56  Offline
Joined: Nov 2002
Posts: 558
young harris georgia usa
JBD,thanks for the link. I run across this problem frequently,and usually find nothing wrong.

Customers always expect a "fix" and look at you strangely when you can't offer an explanation for it.


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