[antipode12]

A few of you helped me out on my previous problem (https://www.askmehelpdesk.com/electr...al-253755.html) but now there's a new problem:

After fixing my "open neutral" problem, I noticed that the outlet now read "open ground." I didn't think anything of it. This house had many of those (since corrected) when I bought it.

I went to take a shower, though, and the shower head and faucet zapped me. This has never happened before.

What do I do?

FYI: I had a plumber in yesterday and he moved some piping (copper) already existing, and he added a PVC T-connector onto a main drain pipe; he also replaced a sink drain with a PVC one.

Also, I had the ceiling drywalled three days ago: possible that a stray screw pierced a wire?

My cable in the junction box is BX style, and it had a metal strip in the cable that I think is called the bonding strip -- I wrapped that around the outside of the BX sheath.

[donf]

More than likely the plumber is your culprit.

By installing a PVC pipe, he destroyed you cold water ground.

[Stratmando]

You need to turn circuits 1 by 1 to determine which is causing it. If a hot wire touches ground(bx cut into it, Cover pinching it, whatever) and the ground is not intact, it will become live.
Be careful testing, as Bx, and any metal boxes may be live. Look for voltage on the ground. Separate wires or circuits as necessary to isolate. Be sure ground is intact at panel.

[antipode12]

DON: how do I re-set that drain pipe ground? The PVC drain connector is about 12 inches with copper on either side. How do I bridge it?

STRAT: Could it be the drain?

[donf]

Please do not disregard Stratmando's advice.

If you can get to both ends of the new pipe, I would place a 14" #10 AWG wire jumper over the PVC and clamp (bond) the wire to good sections of copper pipe.

Make sure you clean and burnish both sections of pipe so that you get a good bond on both sides of the jumper.

[antipode12]

Don, I'm definitely not disregarding Strat -- he's helped me before : )

So far, I have ID'ed the circuit causing the problem. When I shut that breaker, there is no shock in shower, according to multimeter! (BTW: the voltage in the shower was about 35v).

BUT also, I connected a thin wire (maybe 18 AWG) between the two sections of pipe, and there is no voltage in the shower anymore.

SOOO... Don, you seem to be right -- I need to bond a jumper wire between the two pipes.

BUT, Strat, this means I still have a short in that circuit, right? Any advice? (I checked the culprit j-box and found no problems. The only question is the bonding strip in the BX, which I wrapped around the outer sheath. Correct?)

[[I'm calling it the "culprit" j-box because I worked on it the day before I had my shock problem. Unfortunately, it was the same day the plumber came.]]

[Stratmando]

I would turn off breakers one by one until the 35 volts is gone from both sides, grounds can become live if it touches a hot, or become live if an Appliance failed(for example), shorting to ground and trying to get back to ground.
I would try turning off all lights, and unplug anything on that circuit, 3 prong particularly.
Need to start with which circuit, and what is on that circuit.
Plumbing/drains can pinch or insulation can be worn to allow hot to contact conductive plumbing parts.

[antipode12]

Because of the seriousness of the problem, I brought in a pro -- an electrician.

This is what he/we did:

Isolated the ungrounded circuit... checked junction boxes on this line -- no problems.

Plugged and unplugged items on the circuit. With everything on the circuit disconnected (TVs, computers, lights unplugged -- ceiling fans switched off, etc... ), the short still exists. My volt meter is showing 50v running through the waste pipe.

As soon as I kill the breaker switch, the short goes away.

He checked the panel for problems but nothing there.

He said that the grounding wire to the cold water supply was fine.

Where else can I look?

(FYI, as a stop-gap, we grounded the waste pipe to a nearby junction box so it grounds the short. As we all seem to know, this doesn't fix the root problem.)

[mechanickid]

This was all after the plumber did his work?

Is it a bad jolt? ;)

I would say your problem is fixed because you have jumped the circuit... if you can see all the drain pipes... look for wires touching above the new PVC fitting... this will be the wire using the pipes as a ground... you could move your ground or leave the jumper... were you able to solder it?

[hkstroud]

You should bond the two sections of metal pipe with at #6 wire. Check all connections between the neutral buss and ground rod, including service entrance cable neutral connection. If ground rod clamp coroded, replace. If you have subpanels check to insure that all grounding and neutral connection are correct and proper . Hopefully your pro did all this, but it kind of sounds like he didn't.

[Stratmando]

It doesn't sound like he found the problem, If an electrician could clamp an Ampmeter around the ground jumper, it would show the current drawn. The higher current the higher your electric bill. Would be good to locate, correct, and bond with a #6 as HK mentioned.
Did the Electrician disconnect water heater at the top of heater to eleminate that as a possible cause?
What all is on that breaker?

[antipode12]

this was all after the plumber did his work?

is it a bad jolt? ;)

i would say your problem is fixed because you have jumped the circuit... if you can see all the drain pipes... look for wires touching above the new PVC fitting... this will be the wire using the pipes as a ground... you could move your ground or leave the jumper...were you able to solder it?

Were it that easy... no, most of the pipes run up into finished ceilings and walls.

[antipode12]

You should bond the two sections of metal pipe with at #6 wire. Check all connections between the neutral buss and ground rod, including sevice entrance cable neutral connection. If ground rod clamp coroded, replace. If you have subpanels check to insure that all grounding and neutral connection are correct and proper . Hopefully your pro did all this, but it kinda sounds like he didn't.

My initial thought, too, was to bond the pipe together, but that doesn't correct the underlying cause, does it?

I only have the one panel.

The electrician looked at the ground rod and said that it is only "grounding the meter" and not the panel. (My meter and circuit panel are behind one another -- panel in the garage, meter on the outside of house.) He then said that even so, that doesn't explain the entire problem. He didn't elaborate.

He did check to see that there is grounding wire attached to the incoming cold water pipe.

[antipode12]

Did the Electrician disconnect water heater at the top of heater to eleminate that as a possible cause?
What all is on that breaker?

He didn't -- our water heater is not electric (unless I missed something very obvious).

That breaker is a : it is 15 amp, runs through three levels, and has 3 BR, a bathroom, LR, and basement lighting on it. One of our projects next month was to peel off the bathroom from the circuit and put it on its own 20 amp line.

[mechanickid]

This is how I'm seeing it... it has to be touching the pipe above the new pvc fitting,, because you only recive the shock when you touch the shower spout, your compleating the circuit, there is something,

I'm sure you have already checked but look closly around where the plumber did some work...

Did the electrictian ground the pannel?

[hkstroud]

The panel should be grounded. Grounded to the cold water pipe and to a ground rod. The plumber broke the ground of the cold water pipe when he replace a section of metal pipe with PVC. The connection to the earth was then through the water itself. That's why you got shocked. The bonding wire will remedy that. However, the panel should also be grounded to a ground rod. Also check neutral of service entrance cable connection to neutral bus. Electricity takes the path of least resistance.

[antipode12]

So, to be clear, a house is grounded -- usually -- solely through a grounding rod?

It's not designed to be grounded through the plumbing?

(I'm asking because the electrician made it seem like the grounding rod was only part of the issue, and should not have caused the shock.)

[hkstroud]

No, the service entrance panel should be grounded through two sources, the ground rod and the cold water pipe. There is voltage on the neutral conductor. Electricity only works when the electrons are moving. The electrons can't just jump off the end of the conductor. They have to have path to a lower voltage. Some of the electrical energy passing through a light bulb is converted to heat and light. What is not converted must have a path to a lower voltage. That path is through the neutral conductor back to the pole, or to ground (or you) which ever is easier. When you said you isolated the faulty circuit I think you only identified a circuit that was in use at the time. Note that the neutral and ground come together at the panel.

[antipode12]

OK, so I figured you guys would like an epilogue:

A second electrician came in today and put in a jumper wire grounding the drain pipe to a nearby cold water pipe.

He said that the short that is causing this stray electricity is not really a problem, and it could take a long time to find the short. (He also checked the grounding of my cold water pipe and of my grounding rod, and said that they are grounding fine. He said that my panel is also grounded fine.)

I ask you this: if I wanted to poke around to try to find that short, where might the short look? Do I check outlets to be sure that are tight? Anything else to look for?

Is there anything else I could look for?

[hkstroud]

I don't think you have a short. I think it's the unusued current on the neutral conductor taking a path to ground rather than back to the pole. But I can't explan that if the connection of the neutral from the pole has a good connection at the neutral buss.