How/why are the electric socket wires suddenly both positive
May 24, 2016 6:55 PM   Subscribe

The light socket next to my bed stopped working and the electrician says it's because both wires are positive. I asked him how it could have happened and he said he didn't know, it was very strange. Electricians of MetaFilter, what's happening here?

When the outlet stopped working I called the property manager, who double-checked the fusebox. He then put in a work order for an electrician. The electrician came out, said a piece from something was broken, and replaced the whole thing. Normally I bug repair people with questions so I can learn, but this time I was so busy I didn't even stop to check if it was really working. It wasn't.

He came back out today, and the first thing he said was that he fixed it, he tested it. I told him no, it never worked. No problem, this time we'll test it to be sure. After some more work he tells me the reason it's not working is "because both the black and white wires are bringing power in, when one should be sending the power out." He had a tool that lit up, it's a circuit, it makes sense. But when I asked him how it could have happened, he said he didn't know, that it was very strange. And with that new information, he's coming back tomorrow with different tools to fix it.

Obviously it wasn't always like that since it's always worked. On his first visit he fixes a different problem and says it works, so the wires would have had to be fine. That would mean it switched some time between the time he left and a few hours later when I plugged things back in. He can't explain it. Assuming that's all correct, what happened here?

And in the chance that it's not something that could happen spontaneously, then what could it be? He's the only one who touched it, and he claims it was working when he left last time. Is there a different version of events that could have taken place? Did he just miss something? I'm not looking to blame the guy or get him in trouble. He works directly for the management company, he's one of the senior guys, and has been out here many times. But otherwise, something doesn't make sense.
posted by Room 641-A to Home & Garden (17 answers total) 3 users marked this as a favorite
Best answer: No, that's not something that happens spontaneously. He hooked the neutral wire to hot, which is a pretty bad mistake. Then I suppose he "tested" it by checking that the hot was live, not by actually plugging in a lamp or something.

Was this an actual electrician or just some handyman?
posted by ryanrs at 7:08 PM on May 24, 2016 [3 favorites]

Response by poster: He's on the maintenance team but I don't know if he's an actual electrician, no.
posted by Room 641-A at 7:12 PM on May 24, 2016

Best answer: Is this light controlled by more than one switch? I suppose if someone messed up the wiring of a three-way switched light, you could end up with two hot wires.

Otherwise, if one is to believe this happened spontaneously, you'd pretty much have to believe that somewhere in the circuit a neutral wire disconnected itself from the breaker side of the circuit and connected itself to the hot side. I suppose that's possible, but not very likely.
posted by ssg at 7:13 PM on May 24, 2016 [2 favorites]

Response by poster: I had removed all the lamps and stuff to make room for him to work so he would have had to ask me for one.
posted by Room 641-A at 7:13 PM on May 24, 2016

Best answer: You need to get a real electrician in post-haste. If the neutral is "hot" it could kill someone or start a fire.

By the way, one way this can happen is that the two wires are connected to different hot phases. In that case there would be voltage between them and lamps would work, and it might have been like that for a long time. The voltage would be wrong, but a lamp would still make light.
posted by Chocolate Pickle at 7:15 PM on May 24, 2016 [4 favorites]

Best answer: Sorry, I misread your question as being about a light fixture, when it is actually about an outlet.

Is there a switch anywhere in the mix on this circuit? Can you turn one of the outlets on and off with a switch?
posted by ssg at 7:16 PM on May 24, 2016

Best answer: By the way, it doesn't make sense to refer to a wire as "positive" in AC. The terms are "hot", "neutral", and "ground". If your maintenance man referred to it as "positive" it means he doesn't know what he's doing.
posted by Chocolate Pickle at 7:16 PM on May 24, 2016 [3 favorites]

Response by poster: No switches involved.

You need to get a real electrician in post-haste. If the neutral is "hot" it could kill someone or start a fire.

Should I email the manager and tell him I want an electrician to come out? I could say I talked to an electrician friend who is concerned about fire. Now I'm nervous about him coming back tomorrow, especially if I can't be here. (Or maybe I shouldn't be here.)

I get very anxious when it comes to electricity. I'm not freaking out, but I'm concerned.

Chocolate Pickle, he explained it to me as power in/power out. I used the word positive, incorrectly. Which makes me feel a little better.

I'll come back later if there any more questions but I'll step away now.
posted by Room 641-A at 7:39 PM on May 24, 2016

Best answer: I've never heard the terms "power in" and "power out" used to refer to AC. That doesn't make sense either.

I think the fact that the maintenance man said there was a problem which he couldn't fix is more than enough excuse to ask the manager for a visit by a real electrician.
posted by Chocolate Pickle at 8:10 PM on May 24, 2016 [1 favorite]

Best answer: I'm not an electrician, but you might have a multi-wire branch circuit where the neutral has been inadvertently disconnected. A real electrician is definitely needed.
posted by under_petticoat_rule at 8:15 PM on May 24, 2016

Best answer: If your landlord doesn't believe you, it might be worth $5-10 to buy an outlet tester (available at just about any hardware store). This would tend to take it out of the realm of your word against his...
posted by randomkeystrike at 8:15 PM on May 24, 2016

Best answer: I can believe someone who knew what they're doing would use those terms to try and explain it to someone who doesn't know anything about it even though it's not correct. But it still sounds like you need someone with a little more knowledge. The fact that he didn't catch it the first time sounds like he only has a basic knowledge and does simple repairs.
posted by bongo_x at 8:49 PM on May 24, 2016 [2 favorites]

AC has no positive and negative. Get a new electrician.
posted by humboldt32 at 12:18 AM on May 25, 2016 [1 favorite]

Best answer: Its really hard to tell what is going on in this case with the ability to check voltages and observe their magnitude relative to a known good ground and other hots. There just isn't enough information.

However (warning WAG follows) the hot and neutral spontaneously being hot without sparks makes me wonder if he was using a high impedance meter and was getting a phantom voltage on the neutral. It's a not unheard of mistake for even experienced electricians to make and you can waste a lot of time trying to track down a problem that doesn't really exist.

Electrical stuff can fail spontaneously (and worse intermittently). Usually because of damaged insulation or poor connections (often a poor marretted splice in residential systems) but devices can fail too or something plugged into a circuit can be causing a problem. I chased a bad splice for two days once before I got lucky and the thing opened when I was looking at it. Also it isn't unheard of for multiple problems to present themselves at the same time often because of a cascade failure. Or you can fix a physically observed loose connection but have the real but intermittent loose connection pop up again a short while later.

Here it would be illegal for anyone but a licensed electrician to do anything but the most minor of repairs to an electrical system in a rental property but that isn't the case everywhere and I don't know the requirements in your jurisdiction. If the guy they've been sending isn't an electrician though I'd use the fact that he has had to come out three times to demand an actual electrician if he doesn't manage to fix it this go around.

PS: I've used the power comes in/goes out to try to explain complicated wiring to people unfamiliar with the jargon. EG: your average person isn't going to know the difference between a switch leg and a hot but if I say the power comes into the switch box over the white and back out on the black they can see why there are only two wires in the switch box. Or explain light fed 4-way.
posted by Mitheral at 1:39 AM on May 25, 2016 [4 favorites]

Best answer: There's not enough here to give you an accurate diagnosis - that's part of the reason that licensed electrical contractors generally charge a time-and-materials rate for diagnostics. The actual repairs are usually pretty straightforward.

It sounds like the guy erred on the first repair, and is correcting it. If the outlet works and the plate isn't hot and the breakers aren't tripping, you're likely going to be just fine. This kind of thing is pretty common - both the failure and the mistake in repairing it.
posted by Thistledown at 4:51 AM on May 25, 2016

Response by poster: I emailed the manager and he said he'd talk to the maintenance department. It's also possible this first guy will come back before the manager even gets to talk to the office because he has permission to enter today and I'm leaving.
I can believe someone who knew what
they're doing would use those terms to try and explain it to someone who doesn't know anything about it

He may not know how to fix this but I'm probably the one who caused confusion by using the wrong terms in the first place. I solder a few kits and now I'm an expert!

I'll update once the outlet is working again, thanks all.
posted by Room 641-A at 8:49 AM on May 25, 2016 [1 favorite]

Response by poster: He came back, and this time he brought another guy. The other guy seemed to be in charge, and they checked all of the outlets. They found a different outlet that was also a problem. That one had three wires (red, black, and white) but has been working this whole time. So they did some more work and everything is working. The second guy told me that the second outlet is now wired correctly to work with the mystery light switch by the front door.

I have no idea how much my email played a part in this, if at all, and if this was fixed correctly. But everything seems to be working and this was about as many spoons as I had to devote to the problem so I'm glad it's fixed. Thanks for all the advice.

(And if anything I've written here sounds dangerous let me know and I'll put it back on the to-do list.)
posted by Room 641-A at 10:05 AM on May 27, 2016

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