tingling shocks when using water

Reply

  #41  
Old 04-02-06, 10:57 PM
bolide's Avatar
Member
Join Date: Jan 2006
Location: PA
Posts: 1,909
> So the solution to the open neutral that's energizing
> all the bonded piping is more bonding?

No. The solution is to fix the neutral.
But that's not the problem here.

Furthermore, if the metal piping may become energized, then you bond it before that happens.


> The bonding connection that is guaranteed to energize the
> piping is required because the piping is likely to become
> energized from the bonding connection? Okay, I think I got it.

This is another straw man you constructed. No one said this but you.
It is silly and you know it.


> Are we still cool with hurting people outside, or have we come that far yet?

What else would you do?
Open-neutral detection technology hasn't made it very far and where are any residential systems four-wires? The NEC and NESC don't even leave these as options!


> Are you really thinking that you can outbond an open neutral?

For the most part this is possible inside the house.


> Or are you going to concede that an open neutral is the one infrequent event
Infrequent? At any one home, sure. But it happens every day somewhere.

> that bonding can't cure?
Define cure... but in a relevant thread.
This thread has nothing to do with an open neutral condition.


>>> Let me finish your statement: "...that does not have a circuit
>>> likely to energize it." What size wire would you pull to it?
>> Perhaps #12. Tell me what size circuit energized it.
> That's kinda the point, man. There is no circuit to energize it

Then it never poses a danger.


> Give it thirty years, homeowners and chance, who knows?
If something changes and it may be energized, then it needs to be bonded.


> But hooking a #12 to a pipe on the rough isn't going to do much
> good if a mis-installed 100A feeder I didn't touch forty years
Failure to maintain.


> I get the impression that you're stating that
> I am negligent for not bonding everything I see,
> regardless of the NEC.
The NEC requires that you bond whatever may become energized.


> I have no idea what size his chicken wire is.
> I am dubious as to the effect it would have.
> Figure the surface area of the wire versus the
> surface area of the earth, the wire would be at a severe disadvantage.
This is another straw man you constructed.

All that counts is the percentage that it covers under two bare feet
or your hand, or whatever is on the floor.
Basically, that's 100%.


> Are you with all honesty telling me you actually take the time to bond
> isolated metal ducts,

Could they become energized? Are they where someone could contact them?


> gas pipes,

Pretty much a NEC requirement. Gas cos didn't like it. But it changes nothing.
Gas pipes usually get connected somehow. I recommended a bolted connection for the purpose.

The gas cos need to use dielectric unions.


> sections of water pipe,

If they may be energized, of course.


> wire mesh behind stone,

Yes, only if I am the installer or the installer provided either a lead or a ground rod for this purpose.


For example, if the satellite dish, cable, or telephone has its own electrode, I bond that to the GEC I install.

If the satellite dish is far away and unbonded, I advise the owner that it is improperly installed and is a fire hazard. I offer to fix it.


> Every time you reply this way, it's telling me that if you were to
> walk into a house and happen across an energized I-Beam from someone
> else's slipshod work, you would cluck your tongue at the original
> electrician for not bonding the beam, as opposed to the installer of
> the conductor that's energizing the beam?

Incorrect. I would fault the installer.

> Don't mean to put words in your mouth, but that's how it seems.
You took it wrong.
 
Sponsored Links
  #42  
Old 04-03-06, 07:03 AM
Join Date: Mar 2006
Location: Fort Collins, Colorado
Posts: 159
This entire conversation began because you said that a properly installed bonding system (which I would define as "NEC compliant") could not give someone a shock, or words to that effect. I countered that an open neutral condition could.

You countered that inside a house it couldn't.

After some exchanges, I presented you with a real NEC compliant house that could. You then countered that the chicken wire embedded in the slab would cure everything if it were bonded. That would be an installation above the NEC, whether it worked or not. So whether it works or not is something we're never going to know without chiseling out his cast earth slab, which isn't going to happen. (In case you thought I was talking about a "planet earth to chicken wire" ratio, I wasn't. I was talking about a "cast-earth to chicken wire" ratio determining the effectiveness of the wire.)

If you stipulate that non-NEC-required metal be bonded to counter any open neutral condition, you've lost this argument, IMO: The argument was, can a water pipe in an NEC compliant house shock you? Yes, it can.

Are we still cool with hurting people outside, or have we come that far yet?
What else would you do?
Nothing! There's no practical defense aside from isolation, that's my point.

This thread has nothing to do with an open neutral condition.
Yes it does, an open neutral condition is one of the potential causes for the original poster's dilemma. Every time this conversation swings in a direction you can't control, you change the ground rules (the pure Ufer), restrict it back to the OP (a couple of times), or say I'm building a straw man (I've lost count).

I'm not afraid of being wrong. Are you?

Are you really thinking that you can outbond an open neutral?
For the most part this is possible inside the house.
Possible? Maybe. Practical? Not in the least. Because one grounding path unaccounted for shoots the deal. That's probably why the NEC writes it up as a loss, there's no way to guarantee that a alternate grounding path does not exist for any given spot in the house. Open neutrals are infrequent and seldom fatal, so why wreak havoc trying to compensate for them?

The fact that in the last post, you have lost the "bond everything you see" message, and are back to NEC requirements (aside from the stone mesh), I suppose we have found some common ground to stand on. I am willing to walk away at this point if you are.
 
  #43  
Old 04-03-06, 07:44 AM
dougm's Avatar
Member
Join Date: Sep 2003
Location: The Colony, Texas
Posts: 917
Holy Tesla Coils!!

So, Country Boy, have you found your problem? I think it's probably the well pump.

Doug M.
 
  #44  
Old 04-03-06, 07:56 AM
bolide's Avatar
Member
Join Date: Jan 2006
Location: PA
Posts: 1,909
Smile

> This entire conversation began because you said that a
> properly installed bonding system (which I would define
> as "NEC compliant")

No doubt then that you misconstrued my remark.
Are you saying that the bonding that I suggest does not comply with the NEC?

> could not give someone a shock, or words to that effect.

My exact statement was:
"... proper bonding will drive down the voltage no matter what the source.
It should eliminate the voltage in the bathtub (for all practical purposes)."


> I countered that an open neutral condition could.
> You countered that inside a house it couldn't.
> After some exchanges, I presented you with a real NEC-compliant
> house that could.

You moved the bathtub to the basement floor in direct contact with the earth but refused to bond the drain and the wire mesh in the floor.


> whether it works or not is something we're never going to know
> without chiseling out his cast earth slab, which isn't going to happen.

A qualified engineering study could be done.
My preliminary study shows that it works provided that the right connection is made and that the mesh is electrically continuous.


> If you stipulate that non-NEC-required metal be bonded to counter any open
> neutral condition, you've lost this argument, IMO: The argument was,
> can a water pipe in an NEC compliant house shock you? Yes, it can.

Although, that is possible, you moved the tub to the basement to open the question of possibility.
While the tub was on the second floor with the drain bonded, the probability was slim to none.


> This thread has nothing to do with an open neutral condition.
> Yes it does; an open neutral condition is one of the potential
> causes for the original poster's dilemma.

There is no substantial evidence to support this in this case.
There are no other symptoms of an open neutral.
An open neutral is unlikely. The tub is apparently not in the basement.


> Every time this conversation swings in a direction you
> can't control, you change the ground rules (the pure Ufer),
> restrict it back to the OP (a couple of times), or say
> I'm building a straw man (I've lost count).

I'm trying to answer some questions without straying too far from the actual situation.
I didn't change the rules. Open a new thread on other topics if you wish.

I have tried to constrain to discussion to that it can reach closure and hopefully remain relevant to this thread.


> I'm not afraid of being wrong. Are you?

No.


>>> Are you really thinking that you can outbond an open neutral?
>> For the most part this is possible inside the house.
> Possible? Maybe. Practical? Not in the least.

It might not eliminate the fault.
However, it will solve the tingling problem in the bathtub, and barring an open neutral, it will solve the problem outside too.


> Because one grounding path unaccounted for shoots the deal.

Right. A full Ufer accounts for everything indoors (I tink you agreed).
So from there we could work backward to any path that exists in the absence of a full Ufer.
But you did not define such a path.
You both left it vague, well, there could be one that we don't know about.
And you agreed that such a scenario would be contrived.

Those three points are enough common ground for me.


> Open neutrals are infrequent and seldom fatal,
> so why wreak havoc trying to compensate for them?

Who said anything about wreaking havoc?
I sure don't equate bonding with wreaking havoc!


> I am willing to walk away at this point if you are.
It's your call.
It appears to me that since sometime 20 messages ago we agree about all the details for solving the poster's specific problem under the circumstances actually known to exist.
Nothing since has in anyway contributing to understanding or solving the problem.
It's just hypothetical stuff.

The only difference I see is that you give a lot more weight than I do to the notion that he might have the "rare" disease of open neutral. It's easy to test for one.
 
  #45  
Old 04-03-06, 07:58 AM
Member
Join Date: Oct 2005
Location: USA
Posts: 1,188
I am willing to walk away at this point if you are.
I think that may be true for a LOT of us!

In any case, there's 15 people on the NEC panel no. 5. They recommend changes to Article 250 and a couple more. Maybe someone can summarize this banter and fire it off to the chairman for a comment?
 
  #46  
Old 04-04-06, 07:02 AM
Join Date: Mar 2006
Location: Fort Collins, Colorado
Posts: 159
Originally Posted by telecom guy
Maybe someone can summarize this banter and fire it off to the chairman for a comment?
"Dear Mr. Chairman,

These two hard-headed guys got into a heated debate when they failed to fully communicate their views about the effects of bonding when introduced to an open neutral.

So, what gives?

Signed, "



Bolide, we probably should have opened a new thread, because I wasn't overly concerned with refreshing my memory about the conditions of the original poster's bathtub as I posted, because I had changed gears into fully hypothetical debate to explore the subject of open neutrals and bonding. If you were doing that out of kindness to the OP, and not as a diversion, I apologize.

What is your preliminary study with the chicken wire? I hope you don't get too into it, because cast earth has different properties than concrete, and concrete (while being the most convenient and inexpensive to use for a test) wouldn't be very conclusive. It's more porous that cast-earth, so it absorbs water better, and water is half the magic of a CEE. It would be interesting, and somewhat analogous, but it wouldn't really prove either side. (I guess what I'm saying is, do it, because I want to hear how it works, but don't send me half the bill for the concrete.)

Another factor is, a small pad would be less resistive overall than a large slab, so our results would be a little skewed. I had pictured the tub in the middle of the house, and the connection to the chickenwire at one of the corners, by the service.

If you would permit this to continue away from the OP, here's what I'm thinking. Every wire is what...18 gauge steel? Measuring diagonally, the wires are about an inch apart? I think the wire would only have an effect for less than a quarter of the distance between links, and the cast earth and minerals in the center of the links would pass through to planet earth.

Analogy: Think of a grounding electrode as the tires on a car. If you put bicycle tires on a ferrari, the car will roll; but it won't handle the way it would if it had full size tires on it. I don't think 18 gauge wire would get decent "traction" on the cast earth around it, so there would be a lot of cast earth unaffected by them. IMO.

Then again, you figure the size of a hand and imagine how many links that would cover, then it looks pretty convincing. Interesting.

To answer some of your post (late for work): Yes, extra bonding is NEC compliant. By "NEC compliant" I meant solely what the NEC would require of the installation, nothing more.

An open neutral is unlikely but possible in the OP. Given all the attention this has had, it will not be an open neutral, guaranteed.

A full Ufer would mean a lot indoors. Another component I thought of yesterday that might compromise it (when added to that list) is a metal window frame. Add that to mesh behind stone, a gas pipe running though the stone, and we've found an alternate path not going through the full Ufer. (Provided, of course, we didn't bond the other things due to lack of NEC requirements.) Just throwing that out there, not for argument's sake, more for 'hey, I thought of something else' and that's it.
 
  #47  
Old 04-04-06, 08:14 AM
bolide's Avatar
Member
Join Date: Jan 2006
Location: PA
Posts: 1,909
> If you were doing that out of kindness to the OP,
> and not as a diversion, I apologize.

It's good decorum not to go too far down a rabbit trail.
Otherwise, we might find such a thread to be locked with a padlock.


> cast earth has different properties than concrete,
> and concrete (while being the most convenient and
> inexpensive to use for a test) wouldn't be very conclusive.
> It's more porous that cast-earth, so it absorbs water better,
> and water is half the magic of a CEE.
So much the better.


> If you would permit this to continue away from the OP
Not a good idea.


> Measuring diagonally, the wires are about an inch apart?
You don't say!


> I think the wire would only have an effect for less than a
> quarter of the distance between links, and the cast earth
> and minerals in the center of the links would pass through
> to planet earth.
Even though it has more "magic".


> I don't think 18 gauge wire would get decent "traction"
> on the cast earth around it, so there would be a lot of
> cast earth unaffected by them. IMO.
My study showed that it is very effective.
It actually performs better than 1/4" rebar on 2" centers
(not that the voltage difference for either is enough to be detectable to a human).


> Then again, you figure the size of a hand and imagine how
> many links that would cover, then it looks pretty convincing.
I suppose that's because we all know that a hand is a much better conductor than earth and/or concrete (even with a steel mesh embedded).


> Yes, extra bonding is NEC compliant.
Very generous of you.

> An open neutral is unlikely but possible in the OP.
Abuse of a horse corpse.


> A full Ufer would mean a lot indoors.
> Another component I thought of yesterday that might
> compromise it
What is "it"?

> is a metal window frame. Add that to mesh behind stone,
> a gas pipe running though the stone, and we've found an
> alternate path not going through the full Ufer.
> (Provided, of course, we didn't bond the other things due
> to lack of NEC requirements.)
NEC 250.104(B) "... including gas piping".
Obviously anything which in fact is energized has a 100% likelihood of being energized. I think it's is better to bond it than to have it carrying 5A into the earth undetected, perhaps for years at a cost of a few hundred dollars a year.

Would Ufer approve of failing to bond a gas line in a building? Of course not.
So it is not a full Ufer.
 
  #48  
Old 04-04-06, 07:14 PM
Join Date: Mar 2006
Location: Fort Collins, Colorado
Posts: 159
You don't say!
You're so cute.

What is "it"?
"It" was the Ufer's utter control in being the only ground path.

If you'd like to post what you're doing and whatnot, feel free to start a new thread. I'll keep an eye out for it. That way we can speak freely.
 
  #49  
Old 04-08-06, 04:53 AM
Member
Thread Starter
Join Date: Mar 2006
Posts: 5
Thumbs up answer to puzzle

Well Folks here it is.
My electrician friend did the following.
1) checked all the grounds a) to copper water pipe
b) to outside underground
- checked OK!
2) checked connections to breaker panel
- checked OK!
3) checked for balance between underground feeder lines between road hydro poles and home.
- Checked OK! i.e. balanced with and without load
4) went to outside tap where tingling was first felt and measured voltage between tap (metal) and ground(concrete pad). A surprising 8 volts was measured>
OBVIOUSLY NOT OK
5) with the main circuit breaker turned off, voltage between tap and concrete pad again measured.
Now 5.4 volts registered on the meter
OBVIOUSLY NOT OK
To resolve.
Hydro Utility company was called in and the fault was attributed to 1) poor ground connection on the hydro pole at the road and the feeder hydro pole a short distance away. All connections were redone. Apparently during the winter (Canadian winter), the large amount of road salt used to keep the road way clean, vapourizes and has on numerous occaisions caused the aluminum wire to break down and not allow for proper ground from the home.
Upon completion of all the repairs the voltage was again tested at the outside water tap and was found to be 0.5 volts. This is to my understanding well within the normal range.

EUREKA!!!! no more tingling shocks anywhere.

Thanks again for all the support and ideas... This is a great forum!!!!
 
  #50  
Old 04-08-06, 04:58 AM
Member
Thread Starter
Join Date: Mar 2006
Posts: 5
Thumbs up This is what happened

Well Folks here it is.
My electrician friend did the following.
1) checked all the grounds a) to copper water pipe
b) to outside underground
- checked OK!
2) checked connections to breaker panel
- checked OK!
3) checked for balance between underground feeder lines between road hydro poles and home.
- Checked OK! i.e. balanced with and without load
4) went to outside tap where tingling was first felt and measured voltage between tap (metal) and ground(concrete pad). A surprising 8 volts was measured>
OBVIOUSLY NOT OK
5) with the main circuit breaker turned off, voltage between tap and concrete pad again measured.
Now 5.4 volts registered on the meter
OBVIOUSLY NOT OK
To resolve.
Hydro Utility company was called in and the fault was attributed to 1) poor ground connection on the hydro pole at the road and the feeder hydro pole a short distance away. All connections were redone. Apparently during the winter (Canadian winter), the large amount of road salt used to keep the road way clean, vapourizes and has on numerous occaisions caused the aluminum wire to break down and not allow for proper ground from the home.
Upon completion of all the repairs the voltage was again tested at the outside water tap and was found to be 0.5 volts. This is to my understanding well within the normal range.

EUREKA!!!! no more tingling shocks anywhere.

Thanks again for all the support and ideas... This is a great forum!!!!
 
  #51  
Old 04-08-06, 05:07 AM
Member
Join Date: Jan 2004
Location: Oregon
Posts: 1,219
Thanks for the update! It is good to see a resolution, especially when we have such a long thread about what could or could not be happening in a theoretical sense.

I was wondering if you had the electrician look for bonding between your plumbing pipes and your drain pipes, or at least measure voltage at these points, since you mentioned also getting shocks in your bath tub. The other thing to check would be bonding between your hot and cold water pipes.

Bonding between all of the metal fixtures in your bathroom is not necessarily required (since as you see above we can argue for days about 'is a drain pipe a water pipe' and 'is it a pipe that is likely to be energized' and you are in Canada which has slightly different rules) but IMHO required or not such bonding is a great idea, because it will prevent shocks from external sources such as the power company transformer.

-Jon
 
  #52  
Old 04-08-06, 09:53 AM
Join Date: Mar 2006
Location: Fort Collins, Colorado
Posts: 159
Country Boy, it's good to hear that the damaged neutral connection in the utility transformer was repaired, solving the problem. Sounds as though you discovered the problem before the neighbors noticed the voltage on their plumbing, so that's a good thing too.

Thanks for the update.
 
  #53  
Old 04-08-06, 09:37 PM
Member
Thread Starter
Join Date: Mar 2006
Posts: 5
Winnie (Jon), my copper hot and cold water lines are bonded, as are the water lines and the gas lines. To my knowledge, my ABS drain piping is not bonded to my cold/hot/gas lines any where. I wasn't aware that that was a requirement.

I thought ABS was a very poor conductor of electricity, so grounding would not be very helpful?
 
  #54  
Old 04-08-06, 10:45 PM
bolide's Avatar
Member
Join Date: Jan 2006
Location: PA
Posts: 1,909
likely to be energized

> my copper hot and cold water lines are bonded

What do you mean "bonded"?


> as are the water lines and the gas lines.

Are "water lines" different from "hot and cold water lines"?


> my ABS drain piping is not bonded to my cold/hot/gas lines
> anywhere. I wasn't aware that that was a requirement.
> I thought ABS was a very poor conductor of electricity,
> so grounding would not be very helpful?

Correct. There is no point in bonding plastic pipe.
However, the evidence in this case indicates that your water lines are not bonded to the service panel and that your tub is grounded somehow, but not bonded to the water lines.

The usual ground path for a tub is a metal drain pipe.
Yours might have something else.


Since the problem could happen again, some proactive defense seems to be warranted.
 
  #55  
Old 04-09-06, 06:13 AM
Member
Join Date: Jan 2004
Location: Oregon
Posts: 1,219
Country Boy,

You are quite correct, plastic pipe is not a good conductor, and thus there is no reason to bond to it.

However you mentioned being shocked while in the bath. This strongly suggests to me that something in your bath is 'separately grounded' from your electrical system.

Based upon your description of bonding and what the electrician did, I am pretty certain that all of your metal water piping is correctly bonded to your electrical system and to your required grounding electrodes.

However, because of the grounding failure at the transformer, your entire bonded system (water pipes, electrical system neutral, grounding electrodes, etc.) was raised to a few volts relative to the soil some tens of feet away. This is why you were getting shocks when touching the outdoor spigot. Somehow the water in your bath tub was more like the soil near that spigot than water in a properly bonded system.

If you had a metal drain pipe, then I would suspect that the drain pipe was acting as a unbonded grounding electrode, providing a path similar to standing on the ground touching the outdoor spigot. But you don't have a metal drain pipe.

Perhaps you have a metal tub, sitting on a concrete slab? Perhaps your bathroom is in an extension to your house with its own foundation, and the foundation re-bar is not bonded? Or perhaps the only conductive path to 'unbonded earth' is via the water in the plastic pipe, which would be hard to fix. Regardless, there is something in your bath that is electrically similar to standing on the concrete slab outside and touching the spigot.

If you can figure out what aspect of your bath is acting as a connection to ground which is not properly bonded to your electrical system ground, then I would recommend that you bond it to your metal water piping. In this way, if _for any reason_ the electrical system neutral ever again becomes energized relative to surrounding earth, your bath won't be a shock hazard.

Note that if the only path for this 'separate grounding' of your tub was the water in the plastic drain pipe, the only way that you could 'bond' this is to actually add some metal drain pipe into the water path, and then bond it. But my hunch is that there is something else providing the path to ground.

-Jon
 
  #56  
Old 04-09-06, 07:05 AM
Member
Join Date: Oct 2005
Location: USA
Posts: 1,188
before we send country boy off on a grounding safari:

the evidence in this case indicates that your water lines are not bonded to the service panel
I disagree. The evidence actually shows that bonding does exist. First, the electrician verified it visually. And second, the source of this stray current is carried to the tub by the water pipes. I don't believe that there are any easy solutions to preventing a neutral supply issue from not causing shock sensations in an existing home.
Consider this: how about ISOLATING the cold/hot from the home, thus stopping any stray voltages from arriving to the tub. Use a short section of plastic pipe downstream of the bonding to the existing metal section. THis will still leave the electrical grounding/neutral system from being hot off of local ground. You should then use only double insulated devices in the bath.
The other train of thought that was covered was to use CEE thuout the slab; not something I would consider in an existing home. This would bring up the local ground to meet the culprit neutral issue.
I don't think the risk warrants these actions, however.
 
  #57  
Old 04-09-06, 07:34 AM
bolide's Avatar
Member
Join Date: Jan 2006
Location: PA
Posts: 1,909
Originally Posted by telecom guy
The evidence actually shows that bonding does exist.
Things that are bonded will be at the practically the same potential.


> the source of this stray current is carried to the tub by the water pipes.

I agree. But that's only half the circuit. What is the return path?


> how about ISOLATING the cold/hot from the home?

Bad idea and just as impractical - you are addressing the wrong half of the circuit.


> I don't think the risk warrants these actions, however.

Nor does their efficacy.
 
  #58  
Old 04-09-06, 09:05 AM
Member
Join Date: Oct 2005
Location: USA
Posts: 1,188
Things that are bonded will be at the practically the same potential.
Of course, that IS the purpose of bonding.

OK, so here's where we are at.
The NEC wants us to bond metal "stuff" that could become live and "touchable", presumably thru inadvertant contact with electrical power distribution hardware. However, we do see cases where this mandated bonding is actually the cause of unwanted electrical energy into our bodies. ie; the case where you are in the bathtub and the piping is charged, relative local grounding. There is no law to say we need to bond local concrete, tubs, patio slabs, so lets get beyond that argument. The NEC is demanding bonding to items that can become charged by unwanted contact with AC incoming power.
I'll just say this: If country boy had pvc supply pipes, he wouldn't be getting these shocks. If he was sitting in a fiberglass tub, he likely would not be getting these shocks. I'm only suggesting that an ISOLATED system also has merit, and could be a more financially doable construction method than to lay chicken wire in every piece of poured concrete, bonding the lath behind stucco, etc, in an effort to bring the entire residence earth up to the level of the evil, culprit, defective utility pole ground.
I think most of us have homes that are susceptable to shocks due to boosted wired neutral/grounds. Country Boy is not the exception here.
Don't casually dismiss the isolated water system. There have been enough water utility workers getting shocked from supply water piping "earth currents" to demand plastic pipe sections to prevent this current.
 
  #59  
Old 04-09-06, 09:39 AM
Member
Join Date: Jan 2004
Location: Oregon
Posts: 1,219
Telecom Guy,

I believe that Country Boy has a private well with plastic pipe entering the house, and a private septic system with plastic pipe leading to the septic system. The internal water piping is metal, and properly bonded. (Country Boy, did I get that right?)

The shock path was something other than external metal piping.

The voltage between the outdoor spigot and the concrete pad near the spigot was 5V with the main disconnect to the house _off_.

If Country Boy had all _interior_ plastic piping, then I agree that he would likely have not had any of these shocks. But given that he does have interior metal piping, the question is are there any additional items that should be bonded in order to prevent shocks in his bath.

-Jon
 
  #60  
Old 04-09-06, 10:12 AM
Join Date: Mar 2006
Location: Fort Collins, Colorado
Posts: 159
There's some things here that I see that don't add up.

If there were 5 volts energizing his piping with the service off, his water pipes were energized from a foreign service. This could be achieved with the connection of his neutral to his neighbor's at the transformer, provided he shares a transformer with the neighbor. Then the bad connection to the transformer itself would allow the voltage to flow back.

The more feasible option is that he shares metallic water piping with his neighbor, and the voltage was flowing on the pipe.

Also, if he was in the bath when he felt the shock on a plastic drain, there could have been a path to ground through the greywater running through the plastic pipe. Presumably he is dirty when he bathes, and the inside of the drain is dirty and covered with soap scum, so a conductive path could exist when the inside of the drain is wet. You never know.

Telecom, isolating a section of the metallic water piping system is not a code-compliant option. It needs to be bonded per 250.104(A), regardless of any potential to be energized. If you feel that this is silly (which by all rights you can), submit a proposal to change the section to the NFPA. Anybody can submit a proposal. Perhaps you and Country Boy can communicate further and get details of his installation, and use it in your substantiation for the change.

I don't see them accepting such a proposal, despite the lack of a solid reason to bond it, IMO. But to recommend isolation directly against the NEC is a pretty bold move (not that I'm implying you are). I don't know why they insist on a conductor big enough for a grounding electrode for an otherwise inactive pipe, so I don't feel comfortable ignoring the rule without knowing their reasoning for requiring it. Know what I mean?
 
  #61  
Old 04-09-06, 03:32 PM
Member
Join Date: Jan 2004
Location: Oregon
Posts: 1,219
My wild-a** guess is that the current source is the grounded side of the transformer _primary_ circuit. Perhaps the local distribution network is unbalanced, or perhaps there are bad connections elsewhere on the multi-earthed-neutral. But in any case, some current from this circuit was flowing through ground via the grounding electrodes at the pole. When the transformer ground connection went bad, then this current started flowing to earth via Country Boy's grounding electrodes, raising the potential of all the bonded metal in his house. Just a guess on my part.

-Jon
 
  #62  
Old 04-09-06, 09:26 PM
Join Date: Mar 2006
Location: Fort Collins, Colorado
Posts: 159
Originally Posted by winnie
My wild-a** guess is that the current source is the grounded side of the transformer primary circuit.
That is an interesting theory. Let's take it for granted that the neutral connections were bad, as the POCO guy claimed. If that were the case, wouldn't the transformer start malfunctioning first? Since the transformer is essentially just an appliance wired (HV) phase to neutral, if the neutral were compromised it seems as though the 240V secondary would drop out (or at least get a bit perceivably 'hairy') before it started giving off open neutral symptoms. Don't you think?

Using the grounding electrodes available as a return path for the HV circuit would be more resistive than it's normal conductor. So it seems like the overall voltage would drop quite a bit. In his testing, he might have reported L-L voltage of 210V or something like that, I would think.

Heck of a cool idea, I give you mad props for that!
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes