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Light switch loud popping noise

Posted by rstark (My Page) on
Thu, Jul 19, 07 at 4:37

Hi all,

I just changed all light switches to the newer 1"x3" style rockers. Two different brands of switches make a loud popping noise at random when you turn on or off the light. At first, I thought it was because I used the "stab" method of connecting the wires, but have since terminated the wires with the screw mounts. The noise is at the switch.

Both switches are grounded to the ground wire. When I used the stab method, a different switch (and one of the same ones) made noise. Now one of the original ones and a different one makes this noise. Out of all of the light switches I replaced so far, these are the only two making the noise (one single pole and one three way) out of a total of 27 switches.

I cannot reproduce this noise at will.

Any advice would be appreciated.

Thanks,
Rick


Follow-Up Postings:

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RE: Light switch loud popping noise

You're hearing an arc. Don't freak, it's not dangerous, because it's contained.

Whether it happens depends in part on where the voltage is in the 60 Hz AC cycle when you turn the switch on or off. If it's at or near a zero crossing, there will be little or no arc.

Probably some switches have weaker springs than others and their contacts open more slowly, exacerbating the effect.

Also, some loads cause more arcing than others. Switches for compact fluorescents sometimes do this when turned on, because CFs usually have capacitors on their inputs and no inrush limiting.

You might try better quality switches.


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RE: Light switch loud popping noise

First of all, are you sure the popping noise is coming from the switch, not perhaps an arc from a loose splice in the switch box? Is it a mechanical sounding noise, or does it sound more like an electrical arc? Either way if it's coming from the switch it sounds like your switches are defective. Are they the 99 cent specials? If so I'd replace them with higher quality (and more expensive) spec. grade devices. The cheap ones are just that... cheap. I've found that theres frequently truth to the old saying that you get what you pay for.

As for the backstab issue: I don't want to start an epic debate here, but while the screw terminals are a more solid connection, I personally am comfortable with backstabbing light switches, providing they are wired with #14 wire. Unlike a receptacle it is unlikely that your lighting would be pulling enough current to make the backstab a problem-- unless its like some of these new homes I'm seeing with about a million incandescent recessed lights on one switch...


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RE: Light switch loud popping noise

Hi all, thanks for the replies. That makes sense. The switches are two different brands:

Leviton Decora 3-way Switch #107-05603-2WS
Cooper Wiring Devices Decorator Switch Single Pole with Ground #7501W-BOX

I have no idea if these are cheap switches. Not too many choices on light switch brands (Home Depot, local shop like Home Depot, but smaller).

I did switch all my light bulbs to compact fluorescent right around the same time. What should I look for in a quality switch?

Thanks again,
Rick


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RE: Light switch loud popping noise

Odd... I have many of those same switches and none of them pop. I think you've got some wire connection issues in thos boxes. Either there are some loose splices, or if you used the back-stabs on the switches, they are loose. Pull the switches out, take a good look at your splices, and make sure you don't see any signs of arcing. And while you've got them out, if you did use the back-stabs, pull those out and attach to the terminal screws.


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RE: Light switch loud popping noise

Hi all, just an update:
Thanks again for all of the replies, you were very helpful. I have since re-wired the switches in question using the screws instead of the stabs and that fixed the problem in all but one switch.

Sometimes the pop sounds like its coming from the switch, but tonight, it sounded like it came from the light. What exactly are signs of arcing? Would that be like electrical burns?


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