Loose neutral or hot ground issue?

Thread Starter

polarparadoxical

Joined Nov 10, 2019
4
Hello,

I purchased a older farm house a year ago and have been having interment issues with feeling voltage through the older copper plumbing around the house. After doing some experimenting - there appears to be a stray 24V running through all the plumbing regardless if there is power to the main outside box so I assume the problem has to be originating from outside the house. I had the power company come out and they claim their lines tested good but could not verify if the excess 24v was coming in from the pole/transformer (would be on the them to repair) or as a result of problems with the underground wiring to the house (my responsibility). Does anyone have any advice on easily testing this or convincing the power company to verify the cause of the issue?
 

dl324

Joined Mar 30, 2015
8,918
Welcome to AAC!

Where are you measuring this voltage from? Line to neutral? Neutral to neutral? Under what conditions?

Have you checked your power panel to see if you have any loose connections? Have you checked the grounding for your breaker panel? Are the grounding rods intact?

You'd probably get a more definitive answer by hiring a licensed electrician.

 

Thread Starter

polarparadoxical

Joined Nov 10, 2019
4
Power was measured initially from outside ground rod to ground (24V), outside water spigot to ground (24v) and then measured again after main outside was turned off with the same 24v in both location. Power company sent out a crew who then pulled meter and tested both ground rod again and incoming neutral in outside box again with power off to house and noticed the same 24v draw. Tech seemed very confused and had to call his supervisor for instructions on what to do next and I was told that someone would need to come out to test for ground faults and to make sure wiring was good in both run to house and in the house. As this problem was showing up with the main off, would it be incorrect the issue has to either be in ground wiring to house or in transformer or company power lines? And yes, I have a electrician coming out later this week.
 

be80be

Joined Jul 5, 2008
1,930
More the likely the water lines are not grounded lot of times people fix water pipes with cpvc pipe and can cause this.
But it can be something else like a bad ground rod at the pole or in the panel.
 

MaxHeadRoom

Joined Jul 18, 2013
19,033
If you have proper ground rod(s) , At least two, six feet apart.
Then I would bond the ground rods to any metallic water supply, particularly if it originates from underground.
Max.
 
You need to ground the plumbing separately. Watch for things like PVC water meters and dielectric unions. Underground sections of water lines. Water heaters.

If you have a plastic water meter, then you may need a wire braid across it.

Find that ground bond to the copper, then start bisecting. Hopefully the ground bond will be good someplace and you can work from there bi-secting the copper.

Grounds can be bad if they are twisted without a wire nut.
 

Tonyr1084

Joined Sep 24, 2015
3,578
You have 24 volts when power is off? Breakers are OFF? If you're still seeing 24 volts, do you have an inverter running somewhere possibly feeding power back into the lines? Maybe wind or solar panels?
 

MaxHeadRoom

Joined Jul 18, 2013
19,033
You would need to find out the impedance of the source or voltage difference, IOW does it support a load of any kind, just measuring with a high impedance meter is not going to tell you much.
Max.
 

MisterBill2

Joined Jan 23, 2018
3,874
The description of the problem is still unclear! You have an power feed through the meter that has two phases, both 120 volts, also one of the feed lines to the meter. So there are the three connections provided by the utility. Now you also have a connection to the internal copper plumbing in the house, that is a fourth connection that is usually also tied to the neutral wire from the utility pole to the meter. Then it seems that there is another, fifth connection to a ground rod outside someplace, as well as "an outside spigot."
So which points was the 24 volts measured between? Please clarify that. The "ground" that it all was measured in reference to is still not clear to me. If it was the power drop neutral then that is one thing, if it is a ground rod that is different.
One additional note is that when the main outside was turned off it is not likely that the neutral was also turned off, because most electrical codes demand that the neutral shall not be switched or broken.
And one additional question is what problem is the 24 volts causing?
 
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MaxHeadRoom

Joined Jul 18, 2013
19,033
If this is a farm house, then most likely the water supply could be from a well, which if so in all probability may not be properly bonded to earth ground, if all this is so, and a electrical device, water heater etc, is connected to the well supply then there is a possibility that leakage from the unit to the copper water supply pipe is the cause.
It would be interesting to know if the 24v can support any load, i.e. light a 12v/24v lamp etc.
If it is capable of supporting a load, then it is definitely a potential safety issue.
Max.
 

MisterBill2

Joined Jan 23, 2018
3,874
One more question is about the measured voltage in the various circuits. What do they read each side to neutral at the entrance panel?
 

Thread Starter

polarparadoxical

Joined Nov 10, 2019
4
If someone can correct me, please do. So the house has 2 120V incoming hot lines along with a neutral from the pole that run to the box on the side of the house, and then there is a ground rod that runs from the box into the ground. Power flows from 120V volts lines and then dumps any difference between the two 120V back into the neutral line which then feeds the excess into the ground.

I guess i'm just confused because with the mains off, as in, meter pulled - there is a 24V charge running through all copper lines in the house (basement plumbing, outside spigots) and through the ground rod that connects to the outside box. How is this possible with no incoming power unless its being fed in through the neutral from the pole, either from a short in the underground wiring (I don't have overhead wiring) or from a bad transformer, etc? A lot of response have been about improper internal-house grounding and leakage from this or well pump but I'm not sure why any of those would even be a question if the problem is occurring without power being allowed into the house or well pump and no, i don't have any inverters or things magically creating power.

Also, the issue is that I literally get shocked when I need to turn a spigot or use the washtub downstairs, etc.
 

BillB3857

Joined Feb 28, 2009
2,497
A silly question, but is the 24V AC or DC? If DC, and not able to carry a load, it may be from galvanic reaction to metal pipe that also has contact with the earth.
 

MaxHeadRoom

Joined Jul 18, 2013
19,033
Are you saying you experience electrical shock without service being connected?
I suspect your grounding set up is inadequate, The neutral of the service supply should be connected to the ground rods at the panel ONLY.
There is no "excess to ground" , the only time ground current should flow is in the case of a device or powered unit with a ground fault on it existing..
Also if the ground conditions are poor where you, a mains GFI/RCD is often fitted.
You should have at least two 8ft ground rods approximately 6ft apart. One is insufficient and does not conform to code, how old is this installation?
Max.

.
 
MaxHeadRoom-

You stated "You should have at least two 8ft ground rods approximately 6ft apart. One is insufficient and does not conform to code, how old is this installation?".

I do not think the NEC requires two ground rods. My house had new feeds from the pole run underground to the meter installed around 6 years ago, with only a single copper ground rod right at the meter. This was done by our local electric power company.

As to the original problem - isn't 24 VAC what doorbells used to run off of?
 

Thread Starter

polarparadoxical

Joined Nov 10, 2019
4
Yes, I am being shocked and measuring 24v on the ground wire from the box and on copper with the box both flipped off and with the panel pulled. There was an older install so there is only 1 ground rod that runs from the box into the ground. I purchased a second and was planning on installing it but became confused when I noticed there being a constant 24v even without power being allowed into the house. So I guess my question is, again, irregardless of there being 1 or 2 grounds, or even if the grounding point for the box is faulty - where can this stray 24v come from, if not coming IN from the neutral line?
 

Tonyr1084

Joined Sep 24, 2015
3,578
I'm interested in knowing what two things are you touching when you get the shock? The water stream and ? ? ? The pipes and ? ? ? You don't get shocked by touching a potential 24 volts unless there is a return path.

Honestly we're all trying to help. But to help adequately, accurately and safely we really need a clear picture. I must agree. 24 volts when the meter is disconnected (absolutely no power into the house) is a mystery. I'm wondering if someone hooked up a sneak tap into one of your circuits and even though power is off at the meter, power is still on somewhere. At best I can only guess.

I had a ground rod adjacent the garage. It was an aluminum rod. Been there quite a while. One afternoon when I was cleaning out pine needles out from between the fence and garage I accidentally kicked the rod. And it wasn't a hard kick. The rod snapped. I definitely replaced that with a copper plated steel rod driven 7 feet 6 inches into the ground with 6 inches sticking up. Just because you have a ground rod doesn't mean it's doing its job.
 
If someone can correct me, please do. So the house has 2 120V incoming hot lines along with a neutral from the pole that run to the box on the side of the house, and then there is a ground rod that runs from the box into the ground. Power flows from 120V volts lines and then dumps any difference between the two 120V back into the neutral line which then feeds the excess into the ground.

I guess i'm just confused because with the mains off, as in, meter pulled - there is a 24V charge running through all copper lines in the house (basement plumbing, outside spigots) and through the ground rod that connects to the outside box. How is this possible with no incoming power unless its being fed in through the neutral from the pole, either from a short in the underground wiring (I don't have overhead wiring) or from a bad transformer, etc? A lot of response have been about improper internal-house grounding and leakage from this or well pump but I'm not sure why any of those would even be a question if the problem is occurring without power being allowed into the house or well pump and no, i don't have any inverters or things magically creating power.

Also, the issue is that I literally get shocked when I need to turn a spigot or use the washtub downstairs, etc.
OK, now I will correct because you do have it wrong. The return from the two 120 colt lines IS NOT through the ground rod to earth. The standard electrical setup in houses here in the US will function very well with no local ground connection at all. The local grounding with the ground rod and water pipe connections is to reduce the shock hazard if and when something goes wrong. That is the main intent. The local grounding does have a benefit of being part of a redundant system keeping the neutral wire close to the local ground potential. So while th circuit is the same the purpose is quite different.
What I do NOT see is any mention of a neutral wire connecting the neutral line from the pole to the neutral connection in the distribution panel. That wire MUST be connected and it must be a solid connection. If it is aluminum it may have built up an insulating film of aluminum oxide. After those connections, THEN there should also be, tied in at the distribution panel, a connection to the ground rods and a connection to the cold water piping in the house. The water pipe connection is based on the theory that somehow water pipes are grounded, which is sometimes true. The very first thing to verify is that the neutral wire from the pole is adequately connected to the neutral in the distribution panel. A voltmeter check should verify that there is no voltage across that connection. Then you can do a voltmeter check between that same ground in the distribution panel to the copper plumbing in the house. There should not be much voltage between those, either. But really, grounding the plumbing is more a protection against shocks from lightning strikes.
These checks will show you where there is a problem, but they will not fix it. That will take a visual examination of connections. I have found broken grounding cables and a failed neutral wire in the cable from the meter box up to where it was connected to the cable from the pole.
 
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MaxHeadRoom

Joined Jul 18, 2013
19,033
MaxHeadRoom-
You stated "You should have at least two 8ft ground rods approximately 6ft apart. One is insufficient and does not conform to code, how old is this installation?".
I do not think the NEC requires two ground rods. My house had new feeds from the pole run underground to the meter installed around 6 years ago, with only a single copper ground rod right at the meter. This was done by our local electric power company.
Here CEC is used which conforms very closely to the NEC, here the local service supplier requires 2 GND rods, 6ft apart, as a least requirement.
The general rule is that A metal well casing is not required to be a part of the grounding-electrode system; however, the metal well casing is required to be connected to the well pump circuit equipment-grounding conductor.
I would ensure this is so, for starters.
Max.
.
 
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