An estimate for a rewire turned into a troubleshooting call today... "Getting shocked by the tub" was the red flag...

Sure enough, (while in the middle of panic on another job to finish a rough-in...) the volt-tic was singing and flashing when touched to the drain... The Fluke read 35 Volts to the water pipe...

Dismantling the vanity light-medicine cabinet provided no answers, but it is on the same circuit...

So I go down in the basement to see if I can find any voltage readings that were equal or more than 35V to hopefully point me to the source... Testing with the volt-tic first, I found that it would readily sing even on the renovated PVC drain pipes connected to the tub and sink !!!

Running out of time and needing to get back to the jobsite (Allegheny Power had shown up to connect...) and after finding out that the tub had been recently reglazed and the customers were to not use the tub for another five days anyway, I begged them to allow me to return tomorrow, and to please not use the tub or sink until I say it's OK...

Anybody got a guess?




[This message has been edited by sparky66wv (edited 08-21-2001).]

My guess is that if you get "them" bonded, perhaps the OCPD might operate.

There must be a lot of iron in the water.

("them" be anything showing a potential difference starting in the basement.)

Why were they asking for a re-wire? Why wasn't the tub guy shocked?

Virgil;
when it rains it pours....
tape your volt-tic on & to the pipe, or position whatever meter you have to read the 35V, then start flippin' breakers. At least you may find the offending circuit , as it may be some rx simply making contact with a pipe anywhere. If your luck enough to make good on this, a point to point check on said circuit may be needed to reveal the culprit.

This picture shows my Volt-tic lit up... touching the PVC drain pipe...



This picture shows the Volt-tic dead an inch away from the PVC to show that it isn't stray voltage making the whole area "hot"...

All the pressurized lines are 0 volts, the tub drain was 32.6V TRMS, the sink drain was 33.4V TRMS, the vent pipe in the attic was 44.2V TRMS.

Bonding the vent pipe would cure the sink, bonding the sink would cure the vent pipe, but the tub had to be bonded separately to show 0 volts.

The PVC in the pictures is between the tub and sink, retrofitted to old galvanized drain pipes in the walls, and the vent pipe in galvanized, but 90's into the chimney chase and and doesn't come back into view until up in the attic.

There are no obvious shorts, I even completely removed the medicine cabinet/ vanity lights...

Bonding seems to "fix" it but I'm afraid of creating a high resistance short that could worsen and cause a fire before it trips anything.

It's an old 60A fuse box...BTW...

I've searched everywhere but the chimney chase, and it would be very invasive to get there...

They want a total service change and rewire this Sept, so can I bond it for now or what?

[This message has been edited by sparky66wv (edited 09-04-2001).]

Possible a "false ground". This is when someone decides to replace a 2-wire receptacle with a 3-wire grounding type, and there is no ground in the box. They jumper the neutral to the ground terminal of the receptacle. Or, try disconnecting the individual branch ckt. neutrals at the box, then turning the breaker back on. If there is a change in your readings, or, if the circuit is still functional, this would point to a parallel neutral path.

Sparky,

Is this hot tub GFCI protected?

I'm sorry, I haven't made myself clear... It's just a bathtub that is "hot"... a little play on words...Pardon the pun...

No "Jacuzzi" or Spa...

Just an old iron tub with about 35 volts on it!

Redsy... I'm suspicious that the house is absolutely full of "false grounded" recepts... Lots of Three-hole recepts with old two-wire NM feeding them... Haven't torn into any yet to see if they are (ahem) "bonded" to use the term loosely...

I'll make it a point to look tomorrow.

As far as bonding the pipes and "calling it good" until the rewire... Am I merely turning an electrocution hazard into a fire hazard?


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

Virgil,
the tub has become part of the circuit, you need to isolate which one...

I'm not too clear, visually on the bonding solution. However, if you do it, take an amp reading on the bond wire. That will tell you if there is now a fire hazard.

I have isolated the circuit (#3 of 4 fuses), same one for the bath, and about one third of the recepts and lights in the house. Typical old service.

Yep, reading the current would be prudent, how much is acceptable? Only, say 0 to 1A?




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

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?

If it is not a Federal Pacific breaker panel, then I think you are pretty safe. If there were a severe hazard powered through the panel, an OCPD would have operated.

Your readings don't quite make sense to me.
That's doesn't mean that you did anything wrong. I just don't understand what about the bond wire made the problem disappear. Your readings are better explained by a broken meter.

Or is there a dirt floor in the bathroom?

The bathroom has brand new tile along with the tub being re-finished.

The shocking only occured when they were immersed and touched the hot or cold taps... and the problem seemed to be worsening.

It's a very old 60A Murray fused load center... 4 120's, range and main, the "range " circuit feeding a GE sub-panel to feed new dryer and washer circuits... their range is an old gas stove... not even 110V for a timer... The problem was in #3 120V circuit (on the requisite 30A fuse BTW...#14 wire)

Dspark, by broken meter, do you mean the PoCo's or the one I tested with? I used two meters, my new Fluke T-5 1000, and my old Radio Shack TRMS... They measured roughly the same with the Fluke a little higher as one would expect from an averaging meter.

The Radio Shack TRMS would be suspect if used alone, due to age and performance rating... ("not for commercial use" it says...) but I've compared it to lineman's TRMS meters and "it's close enough for government work"... as the saying goes...



[This message has been edited by sparky66wv (edited 08-29-2001).]

> (on the requisite 30A fuse BTW...#14 wire)
I see that in almost every panel or this sort.

> do you mean the PoCo's or the one I tested with?

Yours.

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

What if you just bonded them to each other but not the panel?

The only other things that kind of fit your data are a 240 V fault where there is no net current flow on the "neutral" you created, or a fault from a source not supplied through the panel to which you bonded that now takes a different path to complete its circuit.

OK, now you're scaring me...



How do I find out?

First remove the bond from the panel?

Virgil;
you went, assessed the situation, gave it a bandaid ( that apparently works, whatever the situation),and are negotiating with the customer as to the ultimate fix.

this happens a lot to me, with the occasional inclusion of the riot act
you have the right to sit in the dark
you have the right to zap yourself
anything you say can be contracted against you
you know the drill

Of recent times, I will do the above, then bill out the service call & bandaid with a written warning
I did so say it,,,see....

If full disclosure is made to the customer, the responibility & liability falls on them , not you. Myself, I have even laid it on the state here ( they have wide shoulders) in this respect
fire..fire..hehehehehe{Bevis&Butthead voice}

I ran across the same problem 25 years ago when a handyman had retiled a bathroom in a house. Voltage readings were in the 50v range, just enough to give a tingle and heat the lead on the main plumbing stack enough to cause it to reliquify. Problem was solved when we removed a single pole switch and discovered a pin hole on the hot from jamming the switch back into the box. Reinsulated the wire reinstalled the switch, problem solved.