Is it normal for water line to be carrying current?

[Red Squirrel]

Saw a post on Reddit of an improper ground (used gas line) and the entire pipe was glowing red, it got me thinking there must be an insane amount of current going through there, when there should not be ANY. Then I put a clamp meter on my water line where my ground goes to... sure enough, 3 amps! I turned on the toaster, 7 amps! Clothes dryer and oven did nothing, turning on certain 120v loads decreased it... depends on which leg it's on I guess as the loads will cancel each other out if they're opposite.

Anyone with a clamp meter want to go try that? I did not figure any current was suppose to actually flow to ground during a normal condition. Wonder if I actually have a problem, or if it's actually normal. If it's a problem, then it's probably been that way for who knows how long, but I'm going to probably want to look at fixing it. Guessing there may be a break in the neutral going outside or something. I'm going to have to get on my roof and measure to see what I get up there.

 

[NetWareHead]

You need an electrician IMMEDIATELY. There should not be any current during normal everyday usage going to the ground. Off the cuff (Im not an electrician), Id say you have an improperly connected ground or neutral somewhere in your house.

 

[Greenman]

Issue with you'r ground circuit, unless the water main is the primary ground. The neutral and ground wire end up at the same place, but the path between is where problems occur. Check the ground at the main, if it's not functioning then the path to ground will be through the bonded portions of the GES.

 

[herm0016]

https://en.wikipedia.org/wiki/Single-wire_earth_return


maybe the neutral at the pole has an issue?

i would call the power company first, as i think it is more likely a problem there, vs at your box. make sure your neutral is bonded to ground at your panel, if some neutral and ground are mixed on each side and the panel is not bonded, then you could have this issue as well.

 

[Humpy]

I seem to remember that a small current could be normal?

Something about parallel paths to ground yada yada.

 

[Subyman]

A house I recently renovated had a small current through the copper pipes. Even with the main completely off. Electrician said he had seen that before and he figured it was either a neighbor's house or the utility company had a short somewhere nearby underground. It is very typical in a larger city where there are street lamps and other municipal electrical units. Some street lamps can even give you a little shock!

However, I would definitely get an electrician out there to make sure everything is proper on your end.

 

[Mike64]

I seem to remember that a small current could be normal?

Something about parallel paths to ground yada yada.

3-7 (whole) amps is a "small current"?

 

[Subyman]

3-7 (whole) amps is a "small current"?

No way. That's killer current.

 

[Humpy]

3-7 (whole) amps is a "small current"?

Clearly not.

I was commenting on the OP's idea that there should not be any current.

 

[Red Squirrel]

The amps change based on the loads I have on too, 7 is when I went to turn the toaster on. Depending on where the load is plugged in it may even cancel out.

So I decided to open up the panel to have a look. I have a cut off switch before the panel so I opened that up first. There is a neutral coming in from the meter which connects to a bus bar, then all the ground/neutral wires for the system connect there too. I did not notice if there is a separate ground coming from meter, now that I think about it, but not sure if that matters as I'm not even sure if a ground wire would be provided by utility. This is an older house so I don't imagine there is any ground rods, the plumbing is main ground.

Interestingly there is a neutral and ground going to the panel, but they are connected together at the panel. Not sure if that's suppose to be like that given they are already connected together at the main switch.

I also measured the current on the two neutrals in the panel and the amperage was higher than what is on the pipe, so that tells me not ALL the current is going there. Though even if I measure both wires separately it's sorta split, even though they're connected together at both ends. But guess that's normal I think? Current flows on all available paths and not just one.

When it's not raining I will go on the roof and check out the neutral and measure there too as I have no way of measuring inside the cut off box, as it's too tight to insert clamp meter, and even with switch off it's still live in there so don't want to shove anything too far. But now I have a bigger disaster on my hands, when I turned off the power for whatever reason my UPS never picked up properly and it killed my file server. So electrical issues that have possibly been there since forever are the least of my worries, my entire network took a huge dump. All my VMs, everything, is on that server, and it won't come back up. I really need to move to a dual conversion setup, but that's expensive and parts are hard to find. (telecom grade rectifier/inverters)

But once I get that settled I will investigate this further as it does not seem right.

 

[Greenman]

As I said, the issue is the ground at your service. The ground path is through the plumbing, not a driven rod.

 

[Red Squirrel]

Yeah next day that it's not raining I'm going to go check out the mast and measure the neutral there to see if any power is going through it or not. Though I suspect I will see some power since the power at the pipe is not the same as the power coming out of the panel neutral. (clamped both the ground and neutral wire at same time, they both go to same place and are connected at both ends)

 

[NutBucket]

Earth ground and neutral should be bonded at the panel, so that is correct. If you don't have any ground rods it would probably be wise to add one. It's a 6' copper rod. Drive it close to the panel and run the ground cable from the panel to the rod and then to the cold water pipe.

 

[Mike64]

I was commenting on the OP's idea that there should not be any current.

Ah, OK, I just wanted to clarify that, it just took me rather aback without further explanation. And it's quite true that it could be something less serious/dangerous than that amount of "raw" current flowing straight through the plumbing (else you would think the OP would've found out about it "the hard way" rather than having to measure it with a meter, especially a clamp-on meter, which isn't actually directly measuring anything... As you allude to, electricity can be really weird stuff, but that just reinforces the need to call in a pro, even if it turns out the answer/explanation is less scary than a literal reading of the OP implies...

No way. That's killer current.

Yeah, clearly, I guess it was my turn to leave out context, I meant it as irony (or whatever exactly one calls non-snarky sarcasm-for-effect...)

 

[Mike64]

and then to the cold water pipe.

Is that really correct? I used to know a (very) little about the more fundamental issues of house wiring, but am very fuzzy on it at this point, but I have the idea that while bonding the service ground to plumbing used to be "the done thing," it's actually not supposed to be under modern codes and could in fact be at least in part what's causing the OP's weird readings? (NB: It's entirely possible that I'm either confusing that with something else or just making imagining the whole idea...)

 

[pcgeek11]

No way. That's killer current.

Hell a quarter of an ampere can kill you.

 

[NutBucket]

Bingo. Just has to find a path across your heart....say from the right hand to the left hand, for example.

And Mike64, in the days before ground rods neutral was only bonded to the water main since, in effect, it is the same as a dedicated ground rod. The ground rod was added in recent decades....probably to improve the "connection" to the earth. Or maybe in case the utility companies weren't installing metal water mains?

 

[herm0016]

Interestingly there is a neutral and ground going to the panel, but they are connected together at the panel. Not sure if that's suppose to be like that given they are already connected together at the main switch.

This is wrong. they should only be bonded at the main, which should be where ever the 100 amp or so breaker is. My house has what i think you are describing, a main shutoff in a small panel where the neutral is bonded, and 2 sub panels where the neutral and grounds are separate.

 

[herm0016]

Is that really correct? I used to know a (very) little about the more fundamental issues of house wiring, but am very fuzzy on it at this point, but I have the idea that while bonding the service ground to plumbing used to be "the done thing," it's actually not supposed to be under modern codes and could in fact be at least in part what's causing the OP's weird readings? (NB: It's entirely possible that I'm either confusing that with something else or just making imagining the whole idea...)

waterlines are still required to be grounded when they are copper. New codes provide for pex which of course, does not have to be grounded.

its not necessarily that the service is grounded to the water lines, but that the service and waterlines are connected to the ground rod.

 

[Red Squirrel]

This is wrong. they should only be bonded at the main, which should be where ever the 100 amp or so breaker is. My house has what i think you are describing, a main shutoff in a small panel where the neutral is bonded, and 2 sub panels where the neutral and grounds are separate.

Yeah I suspect it's wrong too, though I don't think it makes much of a difference in my case does it? Panel can sorta be seen as an extension of the cut off box. Basically it IS the main. Though code wise I think it would still be considered a sub panel. It is right next to the cut off and has a 1 inch long conduit going to it with 4 wires in it, 2 black (the hots) and 2 white, a big white and smaller white (neutral and ground) that are connected at both ends so essentially combined as one wire.

Interestingly when I measure the individual ground/neutral wires there is a bit of current going through both, this is normal though right? Current will flow equaly through all paths available based on their resistance. There is more current going through the big wire Could that be what is happening with my water pipe? I confirmed that not all the house current is flowing through there, maybe about half. Ex: when I measure the two cables together at the panel I get more amps than I get at the ground wire going to the pipe. Though I'd imagine most of the current would still be going to the pole as that is a much lower resistance path than earth ground.

I still need to go check outside to see how the neutral looks like as the only thing I can think of is that maybe a connection is loose or corroded somewhere. If I can prove the trouble outside then I can just call the power company. I'm fairly confident at troubleshooting this but failing that I will probably get an electrician. Who knows how long it's been like this though, I just had the random thought to put the clamp meter on the pipe to see if I get a reading.

As far as ground rods I've heard of them many times but never actually seen them anywhere, how are they typically installed? Like are they actually driven in the basement before the foundation is poured? If they are outside then you still need a wire going to the panel inside, or would it just go to the meter pan? Either way never actually seen such a wire on any house. I wonder if the codes may be different here, but everything I read does mention needing at least 2 grounding rods in addition to the water line, and gas line should be bonded too, but should not actually be used as main ground. In my case I don't think that is the issue though, the ground rods are more to act as extra protection. Basically if you have a bad neutral and a poor plumber happens to cut the main line to do work... youtch!

Oh, and my install is SWER I believe. There is a single HV line in my back yard with a transformer at a pole further down the line, then the low voltage line is just below.

 

[NutBucket]

If I understand it correctly, the ground rod should be the main ground. IMHO bonding gas and water lines are for safety more than anything. You wouldn't want any stray voltage in those systems.

I'm not sure how long they've been using ground rods but it could be your panel was installed before they were required. Every home I've seen that's had a panel upgraded/installer in the last 20 years has one.

 

[natto fire]

A few things. The grounded (neutral) and grounding (EGC or just "ground) systems should only be bonded at the first means of disconnect. Any other panel fed from there should have separate neutral and ground bars and should not be connected together electrically, known as bonding.

All metal parts should be bonded to the EGC, and there should not be any current flowing on any EGC wires. This doesn't always pan out in practice, but you definitely have a neutral problem.

The current that is supposed to be flowing on the neutral is roughly the difference between the current of the two legs feeding your single phase system. You do not have a SWER system, or you would not have a neutral wire in your service drop. The single wire you see is the single phase, which is fed to a transformer, the center tap from the transformer becomes the neutral which is bare in the triplex used by power companies down here, and the two insulated lines are the two legs from the split single phase.

The reason the current changes when you use 240v loads is because the current using the water pipe as a return path now has another path through the 240v load.

Ground rods or grounding electrodes are supplemental grounding, and because the resistance of the earth is usually pretty high, they will not carry enough current by themselves to trip a circuit breaker in the event of a ground fault, hence the neutral/ground bond at the first means of disconnect. I'm assuming you are on a municipal water system? If I had to guess, your neutral is damaged either in the meter can, or the splice at the weatherhead, your neutral current is going through the water system, to a neighbor who is on the same transformer as you, and then back through their neutral.

Call the power company and tell them what is going on. See if they come out, break the seal on your meter can, pull the meter and then you can look for corrosion or other damage on the neutral lug. I would do that before checking the mast, as it is more likely the can, especially if it is an older one.

Good luck and stay safe. Keep in mind that if that water bond is broken, you can have some VERY screwy things happening when 240v loads are used, including having up to 240v on one leg to "neutral". Broken neutrals can fry electronics which are expecting 120v.

 

[Elixer]

waterlines are still required to be grounded when they are copper. New codes provide for pex which of course, does not have to be grounded.

its not necessarily that the service is grounded to the water lines, but that the service and waterlines are connected to the ground rod.

Huh, I guess that would explain why there is bare copper wiring going to the outside hose waterlines.
The other side of that bare wire looks to be coming out of the electrical panel.

 

[Mike64]

The ground rod was added in recent decades....probably to improve the "connection" to the earth. Or maybe in case the utility companies weren't installing metal water mains?

waterlines are still required to be grounded when they are copper.

its not necessarily that the service is grounded to the water lines, but that the service and waterlines are connected to the ground rod.

Ah, OK. I thought it might've been one of those things where TPTB decided the earlier practice hadn't "really" been safe all those decades they'd been requiring it...

 

[natto fire]

Ah, OK. I thought it might've been one of those things where TPTB decided the earlier practice hadn't "really" been safe all those decades they'd been requiring it...

The idea is for anything that people touch to be at zero potential. That is why GFCI and AFCI have proliferated so much to attempt to alleviate improper installation and other failures of grounding systems. Having a separate grounding system itself is a somewhat new thing, with many homes not having that.