Copper pipe shocked me!!

[Terry]

I was looking at a 3" ABS drain for a toilet in the basement, standing on the plastic toilet seat, accidently touched the 1" copper pipe and WOW!!
I got shocked.

The copper pipe right here.
And then I went outside to check the grounding on the panel, just one rod in the ground, and nudging it with a plastic bucket noticed that it was loose in the dirt.

The homeowner will have that grounding fixed before I come out again. Both her and her daughter had already been shocked doing other things.
It's time to check into it. For sure!

 

[wwhitney]

I was looking at a 3" ABS drain for a toilet in the basement, standing on the plastic toilet seat, accidently touched the 1" copper pipe and WOW!!
I got shocked. . . . And then I went outside to check the grounding on the panel, just one rod in the ground, and nudging it with a plastic bucket noticed that it was loose in the dirt.

That ground rod is not part of the mechanism that is supposed to prevent such shocks. The metal water piping in the house is supposed to be bonded ultimately to the grounded service conductor via the main bonding jumper at the service.

But I agree that an electrician needs to come out and sort out the grounding and bonding before proceeding. If that section of copper happens to be a short isolated section, then it may not be bonded, but the area to search for what's energizing it won't be very large.

Cheers, Wayne

 

[Sponsor]

 

[Terry]

The shocking copper is the incoming 1"
Since I'm the third person to get shocked, it's time to do something. Back when I started plumbing, we were told to have at least five feet of soft copper outside the foundation, this was to be the ground for the panel.

Years later after they found a dead plumber in a crawl space they changed the code to make sure the panels were grounded, with two grounding rods. Now on any repipe of a home, they want the grounding looked into before any repipe takes place.

I'm wondering if there is a hot wire touching the copper somewhere in that house.

 

[LLigetfa]

Voltage present on the protection ground is a symptom of a bigger issue, not a bonding issue. Bonding just insures a better path to ground so that it can trip the breaker on the circuit that has the fault.

Sometimes, voltage on the ground can be from an open neutral in which case better bonding does not trip a breaker.

 

[wwhitney]

Voltage present on the protection ground is a symptom of a bigger issue, not a bonding issue. Bonding just insures a better path to ground so that it can trip the breaker on the circuit that has the fault.

To get shocked implies that both something is energizing the copper pipe, and that the copper is not adequately bonded. Since as you say, if it were properly bonded, a low impedance short to the copper would trip the breaker.

So my point was that bonding is what is supposed to protect you from getting shocked by the copper pipe, it's supposed to cause the breaker to trip if the pipe gets energized. The presence or absence of the ground rod has nothing to do with that mechanism.

Cheers, Wayne

 

[LLigetfa]

On one service call, I found a fault where the neutral was open so all the current the neutral would have carried was instead carried by the ground connected to the copper water pipe. There was so much current that it actually warmed the water in the pipe.

 

[Skeezix]

>>I'm wondering if there is a hot wire touching the copper somewhere in that house.<<
C'mon. Think about it. If there were a hot wire touching the copper pipe it would blow a fuse or trip a circuit breaker.

 

[Reach4]

>>I'm wondering if there is a hot wire touching the copper somewhere in that house.<<
C'mon. Think about it. If there were a hot wire touching the copper pipe it would blow a fuse or trip a circuit breaker.

You presume the pipe is grounded.

 

[LLigetfa]

You presume the pipe is grounded well enough.

TIFIFY
That is where "bonding" came up in the conversation. A poor ground might not pull enough amps to trip the breaker.

 

[LLigetfa]

When I built my current home, I did my own wiring and thought the requisite two ground rods would satisfy the inspector. I had also bonded to both the copper water pipe and the black iron gas pipe in the house. Now the gas service feed to the meter and my waterline from the well into the house are non-conductive so the bonding does not improve the quality of the ground but it does provide a path to ground should there be an electrical short to either.

The electrical inspector insisted that I bond my service ground to my metal well casing. I could find no code reference requiring it and no electrical engineer I asked could either but it is best to comply so that is what I did despite concerns of electrochemical corrosion.

 

[wwhitney]

The electrical inspector insisted that I bond my service ground to my metal well casing. I could find no code reference requiring it and no electrical engineer I asked could either but it is best to comply so that is what I did despite concerns of electrochemical corrosion.

The well casing is certainly a better earth electrode that a could ground rods.

As to whether it's required or not, the applicable citation is NEC 250.50 which says "All grounding electrodes . . . that are
present at each building or structure served shall be bonded together to form the grounding electrode system." So it becomes a judgement call as to whether the well casing is present at the building, or if it's far enough away to say it's not present.

Cheers, Wayne

P.S. The word "grounded" is overloaded, as it is used to mean both "bonding" and "earthing," the latter being a connection to the earth itself. In the case of the OP, it is the bonding that is of concern, not the earthing. If the metal water pipe is properly bonded to the service neutral as required, then any circuit that could energize it will cause the breaker to trip (if the fault is of sufficiently low resistance).

Cheers, Wayne

 

[Fitter30]

Years ago when they had aluminum siding touched a condenser and leaned up against the siding lit me up. Homeowner a month earlier wire a new outlet and his wife told me he had problems with pulling the wire. 120volts to ground.