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I am not an electrician, but I've been researching a lot recently to try and figure out why my system is behaving so strangely.

Main problem: Lights flickering, sometimes quite severely, and appliances sometimes just turning themselves off or not working properly (e.g. microwave seemingly working but not generating much heat). Last night, for example, my AppleTV turned itself off multiple times while watching a one hour show.

More Info: I have two meters, which feed into two panels that are next to each other, one for the basement, and one for the 2nd floor. The 2nd floor panel feeds into a sub-panel next to it which is for the 1st floor.

I bought some electric meters and testers and have found some distressing things. With a Kill-A-Watt style plug-in meter, I've found that the voltages in my house are often not great. If I try to turn off everything in the house, the voltage everywhere is generally around 120V +- 3V. However, if I put a significant load on (like a space heater or bathroom fan heater), the voltage in half the outlets in the house goes down to around 95V while the other half of the outlets go to 135V. These voltages are not just a transitory spike, they persist as long as I keep the load on. And this is not a enormous, unreasonable load I'm putting on; my space heater that I have been using to make the voltage drop to 95V draws something like 9 amps. I also find that if I pile on more load, I can get one side as low as 75V while the other side goes up to 145V persistently.

I mapped all my lights, outlets, and appliances to their circuit breakers, and I found that all the outlets that go down in voltage together are on one leg of my service, whereas all the outlets that go up are on the other leg of my service. The leg that goes down in voltage is the one where I put the extra load, and I can change which leg goes down and which one goes up in voltage by plugging my space heater into outlets of different legs. The lights that flicker or dim are always on the service leg that has low voltage.

The other interesting thing is that I used a clamp meter on my ground wires from the panel, and I found a significant amount of current flowing through the ground wires between the panels and out to the water main. If I put the space heater in the basement, for example, I can get as much as 5 amps flowing on the ground wires out to the water main, and the clamp meter shows that 5 amps is flowing on the pipe itself out to the outside world. I'm far from an expert, but this concerns me.

I also bought an outlet tester, and I tested almost all the outlets in my house (There are four I didn't test because I didn't want to invade my houseguests' privacy in their bedroom). All but two outlets tested fine, and those two showed reversed hot/neutral.

Several electricians have come in and worked on the system. Each have found real problems and fixed them, and things sometimes get better for a while, but often return. The power company came months ago and found the neutral wire basically totally disconnected in the power feed and the meters. An electrician tightened up a bunch of neutral wires in the panel. Later, he installed the ground system to the water main (there was no connection to the water main before). Another electrican just this week disconnected the ground from the neutral in the sub-panel.

I have another electrician coming in to diagnose and work on the problem tomorrow, but I'm curious if anyone has good ideas as to what might be causing this problem and/or what sorts of tests I should be doing to narrow down the culprit. Thanks!

UPDATE: A power company worker came out and opened up the service box where my meters are connected to the outside. He found that while both hot wires had current flowing, there were exactly 0 amps on my neutral. He undid the neutral connection and replaced it but the neutral still read 0 amps. He agrees the problem is on their side somewhere. Now he's sitting in his van watching TV on his phone while he waits for something. I'm not sure what.

FINAL UPDATE: It took about 4+ hours, but they got it fixed, and I have rock solid 120v no matter what load I put on the house. I'm over the moon. They ended up bringing in a tanker truck with a giant vacuum and pressure washing out the maintenance hole, which was literally completely full of gunk. Eventually they uncovered the wires underneath the muck, connected the neutral, and it's all fantastic. Thanks so much to folks here, especially @Harper - Reinstate Monica, who gave a phenomenal response that was very helpful.

Sasha Aickin
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  • Hello, and welcome to Home Improvement. If an answer is helpful, please click the large check mark next to it to accept. And, please take our tour so you'll know how best to participate here. – Daniel Griscom Feb 18 '20 at 20:01
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    https://diy.stackexchange.com/questions/148995/panel-breakers-are-alternately-90-v-and-140-v/149003#149003 – manassehkatz-Moving 2 Codidact Feb 18 '20 at 21:20
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    @manassehkatz or... i coulda just noticed you linked my other answer lol... – Harper - Reinstate Monica Feb 18 '20 at 22:43
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    @Harper-ReinstateMonica I would have actually written my own answer, but I'm "on strike". Comments and votes only - no answers or edits. Of course I cringe a little when I see new questions that could really use editing, but that's the way it goes. One interesting discussion on the Codidact development site is about Duplicates. It seems that on some SE sites this Question would have been closed quickly as a duplicate. I think, especially when safety is involved, a real Answer (as you wrote) is far more useful/effective. – manassehkatz-Moving 2 Codidact Feb 19 '20 at 00:11
  • @manassehkatz-Moving2Codidact -- one can answer and VTC as dupe, both, if they feel it's needed. – ThreePhaseEel Feb 19 '20 at 00:16
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    "The power company came months ago and found the neutral wire basically totally disconnected in the power feed and the meters. " - and they fixed that, right? – user253751 Feb 19 '20 at 10:10
  • Can I suggest that you pick an electrician and keep calling him until this is fixed? – nomen Feb 19 '20 at 17:54
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    @nomen I'd say OP has been doing way too much of that already. The electricians come out, fix random stuff, do a trick with the breakers to mask the problem, collect the cheque, and leave. – Harper - Reinstate Monica Feb 19 '20 at 18:02
  • @Harper: and then he calls a different one instead of calling them back to fix the problem. – nomen Feb 19 '20 at 18:02
  • "Another electrican just this week disconnected the ground from the neutral in the sub-panel." -- sounds like they disconnected the wrong wire. – Will Crawford Feb 19 '20 at 18:28
  • @nomen: I've been struggling with this question. When someone comes out and tries to fix the problem and fails, do you call them in again and pay the $160 minimum for a service call, or do you try somebody new? I switched electricians only after the first one came like 3 times. He fixed some things and things got better for a while, but now they are bad again. – Sasha Aickin Feb 19 '20 at 18:46
  • @user253751: yes, the power company did fix the disconnected neutral they found last fall. – Sasha Aickin Feb 19 '20 at 18:48
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    @SashaAickin that's your trouble, things getting "better". They aren't going to get "better", they're going to get "right". If they improve it from 150/90 to 140/100, that's no improvement at all. That's why you need to establish a test condition that reliably causes the problem. The only acceptable result is 120/119 fullstop. (Within 1 volt is acceptable). In those test conditions. Otherwise, it's not fixed and they did nothing. – Harper - Reinstate Monica Feb 19 '20 at 18:55
  • @Harper-ReinstateMonica Oh, totally agreed! It's just that I didn't know really anything about residential electricity when this all started last fall, and I only got a Kill-A-Watt like two weeks ago and a multi-meter and a clamp meter last Saturday. So I didn't even know about the voltages drop and spike until maybe a week ago. And I didn't have reproducible case until then because I didn't have meters and didn't understand how service legs work. (And, I think that for a month or two, it really was not reproducible. Had no symptoms, even with high load.) Thanks so much for your help! – Sasha Aickin Feb 19 '20 at 19:05
  • @manassehkatz-Moving2Codidact I'm sorry if this was an obvious dupe. I did click on every suggested dupe that StackExchange showed me that seemed similar, but I didn't see the one you linked to. Thanks! – Sasha Aickin Feb 19 '20 at 19:08
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    Don't worry about it. As far as I am concerned, a fast answer on a safety issue is far more important then "avoid duplicates at all costs". – manassehkatz-Moving 2 Codidact Feb 19 '20 at 19:11
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    @manassehkatz I would say not a dupe, because it's mainly about the sheer difficulty of muddling through months of electrician BS to diagnose, and then, convince the power company of a lost neutral. – Harper - Reinstate Monica Feb 19 '20 at 19:12
  • Yeah, getting them to come out is hard. Last time this happened it literally took 4 weeks from when I reported the problem to when ConEd came out. Because I still have lights on, they don't consider it a "real" outage and basically refuse to come out unless you have an electrician verify. But for a week after my electrician called, they still didn't come. I then called them and a nice customer service rep saw that I had gotten nothing for 4 weeks and I believe he lied on the repair ticket saying I had a full outage. Only then did someone come, like 6 or 7 hours later. – Sasha Aickin Feb 19 '20 at 19:17
  • @SashaAickin Yeah, lost neutrals are devilishly difficult because they masquerade as a working circuit, especially if you have a strong grounding electrode pretending to be a neutral. That's why you must be pushy, dodge their misleading questions e.g. about your lights being out. It's not lying; you do have an outage. Really. It's a broken service wire, which is what an outage is. And the most dangerous kind! The lineman will totally agree it's an outage, even if the office is too dim to know it. – Harper - Reinstate Monica Feb 19 '20 at 20:03
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    Also, it's important to follow my advice and de-energize every 120V and 120/240V circuit at the first sign of a lost neutral, and leave them off till it's fixed. (outside of your test loads of course, but they need to be alone on the circuit). Otherwise you could have 180V on a 120V appliance, and that's a fire-starter. So as a matter of fact, your lights are* out*. – Harper - Reinstate Monica Feb 19 '20 at 20:07
  • Yeah, I've unplugged basically everything at this point in the hopes that things haven't been damaged too much yet. I've also got (at your suggestion) a reproducible case with only one circuit turned on in one panel where a 7A load makes that service leg go down to ~70v as measured at the mains in both panels (even though the load is only on one panel). Now, to wait for ConEd... – Sasha Aickin Feb 19 '20 at 20:23
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    Update: ConEd Emergency truck is here, and the worker opened up my service drop and read 0A on my neutral from the outside world (with things on in the house). He undid the connection and re-connected the neutral with a new connector, and it still reads at 0A. He believes me that there's a problem on their side, and it's outside of my house. I feel such relief. – Sasha Aickin Feb 19 '20 at 21:23
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    Glad you got it resolved. This should be a lesson to those who, for various reasons, think all electric lines should be underground instead of on poles. There are advantages to underground (especially with respect to ice storms, trees, etc.) but this is a situation where it likely would have been fixed a long time ago if the wires were on poles - that is "routine" bucket truck work. But because it was underground, it took a long time until you could somebody to actually get through the mess (literally) to figure it out. – manassehkatz-Moving 2 Codidact Feb 20 '20 at 05:27

4 Answers4

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Turn off 120V appliances NOW. Call the power company and report an outage.

What you have is a classical "Lost Neutral". The dead giveaway is when circuits teeter-totter: when one pole's voltage goes down and the other one's goes up.

This is the most dangerous type of power outage. If you lose a hot wire, half your circuits go dead until a 240V appliance tries to power up and then the dead half comes back at low voltage. Not so bad. But This failure results in some appliances seeing well over 120V, and that can cause appliance burnouts and even start a fire.

95% of the time, the problem is at the power company's service drop from the pole; since that's outside swinging in the wind. So just call them. Report an outage, specifically high and low voltage at your panel main (which you know since it affects many circuits). I wouldn't mention "lost neutral" to the operator as they will sometimes try to talk you out of it, but definitely say it to the lineman!

Meet the lineman and be their "gofer", as the lineman may need you to warn neighbors and/or shut off neighbor main breakers. Being there for that will make the repair go much faster, since the lineman can stay up in the bucket.

Last year my complex lost a neutral. It took almost a week for anyone to detect it; I got wind when my partner said "I'm sorry these waffles are taking so long, the toaster is really slow.” I flew out the door, got a DVM, measured 95V, went in the storeroom (on my neighbor's leg), measured 145V, and called the power company. They said "I'm sorry, we can't come now, we're helping the fire department fight a tree fire. We'll be there in an hour". This was a Sunday. They not only fixed our complex's neutral, but a neighbor's hot that was failing. The neighbor was "living with it", as did all the other occupants of my complex for a week.

About current flow on your safety ground

Your house is trying to return neutral current any which way it can. One way it's trying is through the earth. It's flowing current via your neutral-ground bond to your grounding electrode system, through the dirt, to the transformer's and your neighbors' ground rods. Not a good thing!

Its status, as an extended and protracted problem

The difficulties you've been having are nothing short of insane. I find it inexcusable that a revolving door of professionals cannot fix a reproducible problem like this. It affects both panels, as you say, therefore nobody should be looking at anything that isn't common to both meters. Nothing downline of any meter need to be evaluated, since 1 defect is affecting 2 meters. This is a mind-boggling failure of diagnosis on several people's parts.

It's been a common refrain this week, of people having obvious systemic problems and yet spending thousands of dollars paying electricians to replace individual receptacles and switches. Clearly either the "electrician" has no idea what to do, or is powerless to fix the problem, so does something. This is called "rearranging deck chairs on the Titanic" or "fiddling while Rome burns".

My strongest advice is to turn everything off, and set up test conditions that are effortlessly confirmed: energize 1 circuit on each meter, both on the same pole/leg, and put 1 heater on each, to provoke the problem. Then tell the lineman "Here it is, failing. Make this go away, or open up the meter box and show me where 120V is balanced on my side of both meters, yet imbalanced at my main breaker." Don't let the lineman leave until it's done! And don't let the lineman shut the main breaker off, because that will hide the problem.

This type of repair is very definitive. When it's fixed, it's fixed.

The power company came months ago and found the neutral wire basically totally disconnected in the power feed and the meters.

That sounds like it is exactly the problem. Did they fix that?

Another electrician installed the ground system to the water main (there was no connection to the water main before).

You're kidding me. Obviously your grounding electrode system works, since the house has been returning current on the grounding electrode this whole time. This work was redundant! Better grounding is generally better, but improving grounding to avoid fixing a fault condition is negligent and dangerous.

Another electrican just this week disconnected the ground from the neutral in the sub-panel.

Subpanels must have grounds and neutrals separate regardless, and it's right to do, but it's more rearranging deck chairs and ignoring the core problem.

Funnel them to the core problem

As I said, I'd set it up to induce the problem. Then, pull the cover off both main breakers coming off both meters and measure from neutral to each of the hots, on the supply (unswitched) side of the mains. If both meters and main breakers have this same problem (with the same voltages given static loads), then the problem is before this point - it is between here and the pole transformer. Absolutely forbid anyone to work anywhere after that point. I would wrap the panels in saran wrap and say "We are not touching any of this today. Here is the problem; fix this only".

Now, a small part of this area is in your bailiwick to fix. However most of it is in the power company's bailiwick. Is it possible they've been telling you to fix something and you've just been ignoring them (don't imagine so, but just checking).

Harper - Reinstate Monica
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    I suppose one good thing about 240V compatibility is that a lot of electronics (like Apple TV) won't get fried by this. – user253751 Feb 19 '20 at 10:21
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    @user253751that's true of many devices but not all. Some auto-switch between 120ish and 240ish modes and given 175ish they still let the magic smoke out. (Some) desktop PC power supplies are the most like things to do this. – Chris H Feb 19 '20 at 10:27
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    @Harper-ReinstateMonica: Thank you so much for this thorough response. Electrician came this morning & told me it was ConEd's problem. Called ConEd and they wouldn't even take my report until I got my electrician to call them, and because my lights are on wouldn't commit even to a day that they might come. Last time it took a week from the electrician call to getting them to my house. After railing about this on Twitter, though, I got some DMs from ConEd, and it sounds like they are sending someone out in the next few hours. We'll see! – Sasha Aickin Feb 19 '20 at 18:53
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    @Harper-ReinstateMonica "That sounds like it is exactly the problem. Did they fix that?". Yes, they did fix that, but it only got somewhat better immediately. After the new grounding system, it got significantly better for a month or two, then the problem reappeared, then it was fine for a month or two, and now is hellish again. – Sasha Aickin Feb 19 '20 at 18:59
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    Subpoenas? Subpanels? :) – T.J.L. Feb 19 '20 at 19:35
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    @T.J.L. Apple autocorrect says subpoena is correct. cue "The more you know" rainbow... – Harper - Reinstate Monica Feb 19 '20 at 19:43
  • I mean... In most cases I'm all for electrocuting lawyers, but process servers aren't a whole lot different from letter carriers. No need for them to go into the ground, neutral or otherwise. :) – T.J.L. Feb 19 '20 at 19:46
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    Bloody fantastic answer. OP absolutely needs to get this fixed properly. Last time I had something similar happen to me, I got electrocuted in the shower – coagmano Feb 19 '20 at 23:04
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    Given how often this comes up, this would be a great dupe target for the canonical "open neutral" question. – J... Feb 20 '20 at 01:11
  • Another fantastic and life saving answer from Harper! – Josh Feb 20 '20 at 05:46
  • @Harper-ReinstateMonica yes, replacement comment follows: w.r.t the paragraph about demonstrating the problem, starting My strongest advice is to turn everything off, and set up test conditions that are effortlessly confirmed - heaters and incandescent lights are good as they will tolerate a little overvoltage for a while and undervoltage indefinitely, but unplug expensive and fragile stuff – Chris H Feb 20 '20 at 08:27
  • ...I've deleted my old comment now the replacement is written – Chris H Feb 20 '20 at 09:15
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    @FredStark If you got electrocuted, are you using a psychic medium to log into SE to tell us about it for you? ("Electrocute" means to kill by electric shock. If you were subjected to a non-lethal electric shock, you were "(electrically) shocked" but not electrocuted. – Monty Harder Feb 20 '20 at 17:34
  • @MontyHarder, Safety switches are amazing things! My dictionary says "injure or kill by electric shock", so death is not necessary. But I also wasn't injured, so electric shock is correct. At least where I live, common use includes electric shock in electrocuted because it's easier to say! – coagmano Feb 20 '20 at 23:02
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    In AmE it means death. In BrE it does not, necessarily. Also, no bloody swearing! – Mazura Feb 20 '20 at 23:49
  • @Mazura It's one case where AmE probably has better claim - the etymology of the word is "electric" + "execute" = electrocute; no doubt arising around the time of the development of the electric chair, etc. Not just a lethal shock, but a deliberate one intended to carry out an execution. – J... Feb 20 '20 at 23:58
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    "Electrocuted", in AmE lay conversation, does not neccessarily mean death. It's generally meant to indicate a much more potent & dangerous version of getting shocked. But M-W states: "to kill or severely injure by electric shock". – Self Evident Feb 21 '20 at 04:58
  • I wonder if someone should design a piece of equipment that would monitor the potentials on hot and neutral relative to ground and trigger an alarm if there was an extended-duration potential difference between neutral and ground, or an excessive imbalance on the hots, excessive voltage on the hots, or matching phase on the hots, all of which would indicate emergencies needing immediate power company attention. – supercat Feb 21 '20 at 16:03
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    @supercat Yeah, and maybe it could also measure current passing through it, and have some sort of network connectivity to "phone home" to report trouble, or just report energy usage for billing purposes... seriously there is one right place for such a gadget, the meter itself... but it would need a neutral and ground pigtail, or preferably a CT on neutral. (imbalanced hot flow + zero neutral flow = ding ding ding!) – Harper - Reinstate Monica Feb 21 '20 at 16:22
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With your voltages varying that much from one leg to the next, you definitely have a loose/open neutral somewhere. That would also explain the current draw on the ground wire. If the problem exists on all your meters you might need to call the power company back to recheck their neutral connections. If the problem exists on only meter, then recheck the neutral connections in that meter can. Open neutrals are dangerous so I'm glad you're taking them seriously and getting the right professionals involved.

JACK
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This is a potentially-deadly "open neutral" issue because it can create to dangerously high voltages on the OUTSIDE of appliances. I found mine with one hand in the sink and another touching the microwave.

Mike S.
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I have read through some of these comments and I have to laugh. Do you realize that with this advice that some of you give could have you in legal jeopardy. This was an open/loose neutral condition. On POCO's end to boot. An open neutral is just as deadly if not more than plugging a radio in and setting on the bath tub while you bathe. There is only one way to determine if the loose neutral is at the POCO's point of termination or elsewhere. You would have to open the meter pan and check it right at the head of the source. The only advice that should have been given was to call a qualified electrician. There is certain PPE that is required before opening energized equipment. I am quite sure the home owner doesnt posses this. Or any home owner. Unless you are in the trade. The moral of thus story? Don't get dead. Call a qualified electrician.

Scoobe
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    This is NOT "call an electrician" territory -- this is classical open neutral territory, so their FIRST phonecall needs to be to the POCO'S *EMERGENCY* phone number – ThreePhaseEel Jan 24 '21 at 21:40