Electrical circuit hazard?

Hi,

I caused a problem with an electrical circuit and would like to know whether it's a hazard until my electrician has a chance to check things out.

Scenario: Two switches (a dimmer switch and a standard toggle switch

--three-way, I think) in two locations control the same two hallway light fixtures.

As I was pulling the toggle switch out of its metal box, one of its terminals touched the side of the box and sparked once for a fraction of a second until contact between the terminal and box was broken.

The switches no longer turn on the light fixtures even though power is still being delivered to the switches. If I leave the circuit breaker on (my preference for reasons I won't go into here), would that be a hazardous thing to do, and if so, why?

And if anyone has an idea of why the switches no longer turn on the lights, I'd be very interested in knowing that too.

Thanks in advance for your replies, Darro

Reply to
Darro
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Why were you doing this on a live circuit?

How do you know the switches still have power? Did you verify that with a meter or test lamp?

I see no evidence that the breaker is on; in fact, you've provided some persuasive evidence that it's not.

Probably because you tripped the breaker.

Reply to
Doug Miller

It's because they are broken. Buy new ones, and they should work.

Jon

Reply to
Jon Danniken

Manually throw the breaker to the off position, then on, then off, then on again and see what happens. If no light, you may have fried the dimmer switch.

Reply to
hrhofmann

donmorgan had written this in response to

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: Working on a live circuit can be dangerous. If you do indeed have power to the switches and can confirm this the problem could be that the switches are electronic and not mechanical. They probably are electronic if they are dimmers. Meaning that they use transistors or integrated circuits to function. If you caused a surge by shorting them out you could have damaged the circuitry. The only one affected should be the one that was surged. In a three way configuration the switches work together to pass the power between each other and on to the light. If one goes bad this can stop the flow back and forth between the switches and the light fixture.

Reply to
donmorgan

"Jon Danniken" wrote in news: snipped-for-privacy@mid.individual.net:

Most new dimmers are electronic (using a triac). Not very forgiving to shorts...or as Jon said in a nutshell, iz broke.

Reply to
Red Green

more info at:

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Reply to
buffalobill

ALWAYS turn off the main power to the house before doing electrical work!

I suggest you call an electrician.

Reply to
Bill

Complete and utter nonsense.

Turning off the branch circuit you're working on is quite sufficient to ensure safety.

Reply to
Doug Miller

If he got a spark it's pretty obvious he was working on a live circuit. I do it all the time - carefully of course. If indeed the breaker is on, and power at the switches, he likely blew the dimmer switch. They are not particularly robust.

If you want fun, try replacing a main service panel with the system live!!!!!

Reply to
clare

Tuyrn off the MAIN power????? NO way. Just throw the breaker on the circuit you are working on - or keep one hand in your pocket if you have an idea what you are doing.

If you don't have a good idea what you are doing, call in a "sparky"

Reply to
clare

This would be my answer too.

Reply to
Van Chocstraw

Regarding this thread am sure the advice is good and well intentioned. But IMO don't think the OP is sufficiently knowledgeable to absorb it and/or act upon it; safely. Starting with moving one of the switches on a live circuit, without first checking and shutting off at least the circuit breaker for 'that' circuit. When it comes to shutting off 'all' power in, say, a house. Not necessarily essential but may be appropriate if there is a lot of doubt or confusion and/or if the original wiring/ circuitry has been messed about with, modified and/or obviuosly non standard circuits have been added.

Reply to
stan

I work on live circuits all the time. I'm still here. If you know how current flows you can avoid it flowing through you. If you are a complete idiot, shut off the breaker.

Reply to
Van Chocstraw

And if you have a sudden need for the bathroom halfway through, and wife/child/pet comes in to see the pretty wires while you're gone???

There are times when you have no choice but to work live. When you have a choice, usually better to be 100% safe than 95%.

That's at home. At work it's a different story. OSHA applies, and most of the time you are forbidden to work live. Zero Energy State, Lockout Tagout, etc.

Reply to
TimR

I've been changing switches on live circuits for something better than

40 years - not a shock yet, and only burned off one screw driver, about 40 years back.
Reply to
clare

You put a wire nut on the end if you need to leave a wire live.

Reply to
clare

I don't mean to offend you personally, but I'll point out something.

I've seen a lot of maintenance workers and mechanics over the years in industrial settings.

Without exception - without exception! the ones who were sloppy about killing the circuit power or other safety habits were also sloppy about doing a good job. It was like carrying a sign - "check my work, twice, 'cause it's not gonna be right the first time."

I know that's kind of biased. And you may do perfectly competent craftsmanlike work yourself. But just as a warning, if I know you work live when the circuit breaker is a few feet away, I and most of my peers have concluded you're going to do a half-arsed job, and we're not going to hire you.

It's not easy to figure out who WILL do good work. But there are some clues as to who will NOT, and this is one of them. Sorry if it targets you unfairly.

Of course in your own home, how you do your DIY is up to you.

Reply to
TimR

Not entirely true. High tension lines are worked on live and they have a pole to touch the wires to make the worker the same voltage as the lines. We are talking hundreds of thousands of volts too.

Reply to
Van Chocstraw

When the breaker is 3 floors down at the other end of the building and the only light to work by is on the same circuit, it is safer to keep that light on and work live than to shut the power off and try to work holding a flashlight. Generally on 220 volt and dedicated power circuits I DO shut off the power.

However, when the main breaker on the cottage panel blew, friday of a wintery long weekend, we just grabbed a new panel and breakers before the stores closed, and changed the panel without pulling the meter.Wives holding the flashlights, tape up the ends of the wires pulled from the main breaker, strip out all the branch circuit wires, yank the panel, feed the taped wires onto the top of the new panel, connect to the main breaker, connect the circuit that lights the basement, and shut off the flashlights. Then finish the wiring (get the heat on PRONTO!!!,) then the rest of the cottage.

Generally with light switches I'm troubleshooting live (really no other way to do it, particularly with 3 ways)) and when I find a bad switch I just pull it and replace it.

Reply to
clare

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