Strange electric situation - advice?

[mattmeitzner]

I installed a new subpanel and several new circuits in my basement and just recently passed inspection, fired them up, and they work great. Last step now is to remove the old lights which hang below the joists so that I can drywall the ceiling. However, when attempting to cut off power to these basement lights, I successively turned off every breaker in the main panel, checked the lights, and they were still on! Cutting the main power to the panel kills the lights, but no individual breaker (other than the main) does the trick. Any suggestions?

[JoeSpareBedroom]

Yeah. Official electrician's term: Something's all f***ed up.

Start over, but spend a couple of hours at the library first, reading some books about home wiring.

[Joseph Meehan]

How are you checking the power to those lights? Are you turning the lights on or are you using a meter?

[Kevin Ricks]

Maybe you have a bad breaker that won't switch off. I would remove the panel cover and test the output of each breaker with a volt meter or test light to see if they all really go off when turned off.

Did you shut off all the 240V breakers as well? Another possibility is an illegal tap from one side of a 220V circuit like a dryer outlet or water heater or something.

Or maybe you have another old sub panel somewhere?

Kevin

[mattmeitzner]

Ok, first off - the problem is with the original house wiring, not with what I did so "starting over" is not really an option. Like I said, what I installed works perfectly, it's the old wiring that is confusing. Second - I am testing the lights by flipping breakers and seeing if the lights get switched off, not using a meter - what benefit might using a meter gain me? Third - I will test the output of the breakers to see if one is perhaps bad, maybe that is the problem. I did shut off all 240V breakers, but that's really only the AirCond system as all my other appliances are gas - but still no luck! Also, the house is only 10 years old, and there is NO other subpanel (I'm 99.9% sure of it). Could it be that two circuits are tied together - improperly - feeding these lights, such that killing power to only one at a time doesn't cause the lights to turn off? Other suggestions?

[Pete C.]

Trace the actual wire from the light fixtures to it's source breaker and physically remove the breaker, being careful in case your double feed theory is correct.

[Kevin Ricks]

Thats exactly how I interrupted what you said. No one said anything about starting over?

I suggested a meter or test light tool as a means of testing the breaker output to verify that the breakers are functioning. A bad breaker (shorted on) will show 120V all the time. Of course a good breaker will show 120V when on ~0V when off. Touch one lead to the screw on the breaker and the other on the ground or neutral bus.

I have seen 2 circuits tied together and that would cause what you are seeing. I once found a circuit with a 'home run' going to each end. duh... Just lucky they were both on the same pole. In your original post I thought you said that you turned off all the breakers, but maybe I misread? What I thought you meant was that you turned all the breakers off leaving only the main on and still have a live circuit.

Turn all the breakers off then turn them on and then back off one at a time. See if you find 2 or more breakers that switch the lights back on. If not then go test each breaker with a volt meter as above.

Kevin

[mattmeitzner]

Sorry Kevin, I quoted you, but my response was to both of the posts prior to yours, and then yours as well. JoeSpareBedroom said "Start over, but spend a couple of hours at the library first, reading some books about home wiring.", which is obviously not applicable to me. Also, the meter suggestion is a good one, and I'll try it tonight to check for bad breakers. I also like the suggestion of turning off all breakers and then trying each one ON, to see if two of them power my lights - that's something I hadn't thought of - I only went the other way turning one at a time OFF. I also did try turning off the main feed, which did kill the lights (how could it not, right?), but did not try leaving the main feed on and turning off all breakers (although I suspect that must have the same effect, since the lights couldn't be tied to the main feed since it's 240V, right?). One more question - since the lights are all downstream of a single switch, which works, I should be able to kill the main power, disconnect that switch from the circuit and be good to go, right? No power to switch, no power to lights? That way anything else on that circuit upstream of the switch would continue to function appropriately and even if there was a double-circuit connection upstream of the switch, I would be absolved from having to hunt it down. Sound acceptable or am I missing someting?

[RBM]

The power for these lights may not be in the switch box, as it could be in one of the lighting outlets with a switch leg to the wall switch. I would do what Kevin suggests, as this is a potentially dangerous situation that should be addressed. Kill all the breakers except the main. The lights should go off, then turn on one breaker at a time until you find the one that turns on these lights. Once you find it, turn it off then continue to turn on the rest of the breakers to see if another breaker turns them back on. If so, disconnect an insolate one . Also, as Kevin pointed out, it may be a bad breaker that doesn't turn off, if this is the case, when you kill all the breakers in the panel except the main, these lights will remain on, and this would be the case regardless of how many sub panels you have. At this point you need to test each breaker to find the one that's not turning off

[DerbyDad03]

UPS?

[John Grabowski]

I see this situation from time to time. Usually where a homeowner did some electrical work. The problem may be that the circuit is getting fed by two different circuit breakers. Turn off all of the circuit breakers at the same time to see if that works. If not, open up the electrical panel and see if something is tapped off of the main breaker. There may be a sub fuse box somewhere that you are not aware of.

It is possible that you have a bad circuit breaker that will not turn off.

Let us know what you find.

[mattmeitzner]

Okay, all breakers appear to function correctly - Power when ON, no power when OFF. So I looked at the switch, and it looks like all there might be two circuits connected together right then and there. The box actually has two switches, which are on different circuits, but the hots, neutrals, and grounds are bound together. I disconnected them, took the switch out that controls my lights of interest, and put it back together as it was, just with one switch missing. now the lights have no power, nor is there voltage between the hot and neutral of the wire that goes from the last light to the switch that was removed. I see nowhere else where power might be coming in from, as all there is now is the 4 lights with wires connecting them. I'm guessing therefore that power came from the switch and I've successfully disconnected it. Do you guys think I should continue my search for what was going on here, or just be happy that I accomplished my mission. E.g., is it truly a danger or fire- hazard to leave as-is? Hasn't been an issue for the 10 years the house has been standing. Thanks again.

[Pete C.]

It sounds like someone replaced a switch or perhaps both switches, got confused and ended up connecting everything together.

[dpb]

How can you have "different circuits" if "the hots, neutrals, and grounds are bound together"? If that is really true, then you have a problem that needs to be fixed.

--

[Pete C.]

I expect that it started out as or was intended to be two switches in the box, each fed from a separate circuit (on the same leg by coincidence) and each feeding separate sets of lights, but either the new guy who installed the switches after the rough in, or someone later got confused and thought the second feed was outbound, not inbound and tied it to the other feed. If the OP has them separate now the problem should be fixed.

[Mike Dobony]

Get a circuit tracer that plugs into outlets and light adapters and find the breaker(s) it is hooked up to. I had the same situation and had one circuit hooked up to 2 breakers in a house I bought. The only thing that was good about it was that they were on the same phase. What happened was that instead of 20 amp service to the outlet I had 40 amp service! I took care of it by capping off the extra feed wire to the circuit. My guess is that a wall box has 2 feeds for 2 circuits and they are improperly joined in a box somewhere.

Mike D.

[HeyBub]

$20.00 at Harbor Freight. Just got one but haven't tried it yet.

[dpb]

I was a late bloomer in the thread, but it seemed to me he said that the above was the _current_ state of affairs since he used "is" and "are" not "was" and "were"...

[Pete C.]

The "I disconnected them," and "I've successfully disconnected it" in the OP's post lead me to believe he had corrected the fault.

[jJim McLaughlin]

Theres a surprise.

NOT

He's a jerk, and a lot of folks, me included, have kill filed him.