ECN Forum Forums General Topics of the Trade General Discussion Area "Hot" Tub

Depending on what caused potential difference in the first place, I'm not sure if any current is okay. Theoretically, though, the size of your bonding jumper would dictate the acceptable current. I'd still try to find the reason for the problem. Did you disconnect the neutral on that ckt. to see what happened?

How do you bond PVC drain pipe?????
Don(resqcapt19)

Once again, I have not made myself clear...

Don,

I've bonded to the galvanized pipes that are attached to the PVC, and it's the Galvanized Pipes that are showing the voltage readings TRMS, not the PVC... it just makes the volt-tic sing, which I find unusual.

For testing purposes, I've used #10THHN to bond, but it is not yet in a "permanent" fix... As of now, the three galvanized pieces giving a reading are the sink drain, the tub drain, and the vent pipe coming out of the sink drain. PVC connects the tub and sink in the basement, and that PVC reads hot on a volt-tic.

With both the tub drain and the sink drain bonded, the problem seems to disappear.

It does not go away on one if only the other is bonded, however. That is, the sink drain and the tub drain.

They weren't home when I stopped by today, it'll have to wait til tomorrow...

I'm not satisfied with "fixing" a problem that I have not found...

Redsy,
My concern with bonding at all even with a properly sized jumper is that if the fault is being caused by an actual short, like a nail or screw barely protruding into an old Romex cable, the screw or nail strapping the vent pipe, my concern would be a high resistance short at that point that may heat up and cause a fire in the framing members.

Good thing I enjoy troubleshooting jobs! (Living in WV that is!)

[This message has been edited by sparky66wv (edited 08-25-2001).]

I tend to agree with Redsy that it's a false ground from one of the outlets on the circuit, with the possible addition of a loose or broken neutral splice or connection in the circuit causing voltage to seek ground through the plumbing.
Was there a load on the circuit you identified when you had voltage on the drains?

I've had to ground (bond) PVC before. A local millwright shop used 6" PVC DWV for a new vaccuum system. The air and sawdust moving through the PVC created a HECK of a static charge. We used large pipe bond clamps every so often to "bond" the PVC with a #10 wire along the length of the runs

Sparky66wv, the problem I quoted with a poor neutral connection read a lot like that one you have, one thing I did not tell everyone was it was in WV. Check your neutrals !!!!! Also, Apco had used a split bolt at the pole, which was also bad (doesn't have to be a split bolt) and a good part of the neutral current was traveling down the Cast iron DWV. couldn't get apco interested, had to climb the pole myself to repair the neutral. Also agree with the fella who said check bond path is outlets have been converted to 3 wire from 2 wire, and between the 2 I think your problem is likely there.

Sparky66wv,

The bootleg ground is a possibility. With the shared or common neutral set up that I'm sure this house has, the neutral is probably carrying current at all times. But I wouldnt expect 35-45 volts from a load that's always on (like a clock). Or it might not be a bootleg ground, just a hot electrical box from a hot or neutral in contact with the box.

How do we get from a hot box to a sink or tub at 35-45 volts? It's a funny one.

I've run across this in situations where the tub or sink has a tile surround (tile countertop or floor). The tile bed has chicken wire in it. I've seen instances where this reinforcing wire is in contact with the steel electrical box. If the box is hot, and without an EGC, Viola! the whole counter is hot! The wire mesh is also in contact with the cast-iron sink and tub.

I also saw this once in an old house where a laundry room had been added on. The previously exterior walls of stucco had been left as-is when the space was enclosed. When the new homeowner bent over and around the side of the electric dryer to plug it in, they got a real tingle when they touched the stucco wall. I checked the wall with my volt-tic and the whole damn wall was hot! A voltage check showed 124v on the dryer vent pipe!

I figured the galvanized iron dryer vent pipe was in contact with a hot conductor of the old K&T wiring in the house. Pulled the vent pipe out and saw nothing. The I went to the receptacle outlet on the adjacent (also stucco) wall. Opened it up and there is was--a piece of the metal lath was in solid contact with the box. A check of voltage on the box (using the ground pin of an extention cord plugged into a known good ground) showed line voltage.

Looking closely, I saw that the box was hot due to a frayed hot conductor. There was no equipment ground, which of course would've probably cleared the fault by tripping the CB or burning off a conductor.

If the counter and floor are ceramic tile, this could be the cause.

Let us know!

Every scenario you describe can be found in this house... it's pretty bad...

Bonding to all three galvanized pipes, the two drains and the vent, clears every thing to 0.0 volts and 0.0 amps.

I should have realized that the current was very small (if any) since I didn't get even the smallest spark when I touched the bond wire to the pipe.

The rewire is a definite, and they want me to do it. I also saved his truck from burning up due to a really bad CD player wiring job, he was on the phone with Crutchfield tech support when I showed up...
Someone had decided to use coax to feed the power to the CD player, hot in the core, ground on the shielding. The source to ground was wrapping of the stripped coax around a screw and tightening it with the poor little core getting squished inside... Then the insulated core goes on to the battery hot terminal sans fuse... Sheesh!

I discovered it when sparks started to fly while tracing the origin of the wire while figuring things out for him. (The problem being an "open" at the same location... his tester wouldn't budge...)

To make a long story even longer... He was very grateful...

But back to the topic:

I've left the temporary bonding wire in place until the rewire coming up in about a month. I've told him to call immediately if the fuse blows or if the shocking returns.

Other than that, the "fixing" of the problem would be to rewire it, one bad outlet at a time until it goes away, and by then I'll have rewired the whole thing anyway, so they may as well get an estimate and a reasonable time schedule to do it in.

There's no problem in "selling" a rewire to them, they want it done anyway.

But am I OK leaving it as such in the meantime?

[This message has been edited by sparky66wv (edited 08-26-2001).]

That is a sticky situation. Obviously, it is safer than it was, particularly if an insignificant amount of current is flowing on your bond. If you are sure they will call back for the upgrade, I'd feel comfortable(again, as long as the bond is sufficient). If they don't call back, I'd be more concerned, because I'm not sure the bond is the final answer.

Am I to understand that you just bonded object in the bathroom but did not run the wire back to the panel?

Or did this shut up your volt-tic?

Dspark,

I've bonded literally to the ground bar in the panel... In my opinion it would just be a jumper without a ground source...

0.0 Volts to ground TRMS
0.0 Amps on the bond wire to the panel.

The volt-tic has shut-up.

The only other thing I can do is systematically rewire the house one circuit at a time... but they want an estimate and time to secure a loan first...

What else can I do?