Home Electrical Question

Trying to change a light fixture out and after turning off every breaker in my box…it still doesn’t turn off the light…even with the main breaker getting turned off it doesn’t go out.

  1. Just bought the home 2 months ago
  2. There is only one box (that I can find)
  3. Not sure if there is a battery back up to the light.

Any ideas?

NM, I skipped over #2 for some reason.

Just one box that i can find, i am assuming there is a second one…but its not out in the open.

What type of building? Single family? Duplex?

Location of the fixture? Do you know where the electrical service enters the building?

That would be the place to look for the main breaker box. It is most likely inside the wall where your electric meter is. It sure sounds to me like you have more than one breaker box. My house has been added onto several times and I have breaker boxes in three locations. But the main one, with the whole-house shut-off, is where my meter is, and where the line comes into the house.

I can’t imagine a battery backup for a light, unless it’s an emergency exit light with a battery pack, like businesses use.

My first two thoughts are:

  1. You’ve got a duplex or other such combined dwelling and the light is actually wired to your neighbor’s electrical system.

  2. You say that you turned off the main breaker - do you mean at a panel inside your house or at the actual service entrance where the meter is?

I have a single-family home. Inside the house is the main electrical panel with various circuits but none of them are the actual breaker for the entire home; that is located in the service panel outside of the house. There’s a breaker for that interior panel (plus a breaker for the subpanel I installed in my workshop).

You may find that you’ve got one or more additional circuits wired directly from the main service instead of going first to a subpanel in your house.

I have a cheap-ass tract house built in an eternally hot area. It has it’s breaker box flush mounted on the outside of the house.
Another vote for “the panel you found is not the the main or the circuit is wired directly to the service”.

Until we know this is a single house, we can’t be certain which is more likely.

For most houses, pulling the meter will kill everything, but I am NOT going to recommend that procedure to anybody.

p.s. - if you can turn the light off, there is virtually NO risk to swapping out a fixture.
p.s.s. - the “virtually” weasel word is there because I can’t know if there is anything close to normal in that circuit.

This isn’t true. It’s trivially easy to wire a lighting circuit so that it’s ground-switched. It’s wrong, and in violation of code, but it’s very easy to do. If it’s ground-switched, the wiring at the fixture is hot even if the light is off.

Sorry, small hijack here. I’m going to be replacing a couple lighting fixtures. I’ve seen the tool that you plug into a socket to confirm it’s hot (or not) - what’s the right search term to find an equivalent tool for a light socket or for the wires that get exposed in a hardwired fixture?

Get a cheap multitester at sears or any hardware store. You set it for AC and touch the leads to the wires or socket to see if power is present.

This kind of screw-up (the switch goes on the BLACK wire, folks!) is why I put the “virtually” in my statement.

I’d recommend a non-contact voltage tester for this. They’re not perfectly reliable. Some people will tell you they tell you one of two things: that the wire is hot, or that it probably isn’t hot. That is, they’re somewhat prone to false negatives, which is of course the result you’d least like to have! Careful use can mostly mitigate this issue, though. Test on a known live wire/outlet to verify it lights up, then test on the socket you’re interested in while it’s hot to verify it lights up in there. Then kill the power and confirm the tester doesn’t light up.

The advantage these have over multimeters is that you don’t need any bare contacts or wire to test on. If you’re feeling very cautious, you can follow the procedure above with a non-contact voltage tester, then carefully remove the wirenut on the black (hot) wire, and check for AC voltage between the various blacks and ground with a multimeter. I don’t bother, myself. If my non-contact tester lights up next to the black wire before I hit the breaker, and doesn’t after, then I’m sufficiently confident there’s nothing live in the box.

However, I’ve also mapped out every circuit in my house (old house, some circuits have a definite theme and others are all over the place) so I’m pretty confident before I even do any checking as to which breaker controls which device.

I see in my link the related items selections include a set including the non-contact tester, a multimeter, and a plug tester. That’s the perfect combo of testing equipment if you intend to do any amount of DIY electrical work.

When I’m messing with electricity I prefer to assume that the guy before me screwed up, unless I’ve already verified that he didn’t. Safer that way. :slight_smile:

The house I owned in Omaha had two breaker boxes – one right where you’d expect it to be, and one inside a wall with no access other than to cut away the drywall. I had to get an electrician over to figure out just what the hell was going on. The room where the secret breaker box was had been remodeled at some time in the past and I guess they decided it was easier to just wall the damn thing up than put in an access hatch. Unbelievable, but true. This might be similar to your situation.

About 45 years ago, I had a breaker that would not turn off the circuit off. Turned out the breaker would move like it should, but did not turn off. Are there other lights or outlets that stay on when you try to shut the circuit off?


Wow! That’s strange. Either it’s getting power from somewhere else or there’s another fuse box somewhere.