I am at a loss here.....

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scottdbutcher

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Hey guys! Im new here, been reading your posts for almost a year now, and today i was stumped by something and need some opions! I am an e-2, have alot of experiance troubleshootina and the like, but this on ethrew me for a loop!

So i got a call from a tenant of mine saying when she was touching the tin ceiling in a bathroom of a 2 family i own, she got a shock when she brushed against the shower head. No biggie, ungrouned wire somewhere hitting the ceiling. I tested w/ my ideal bettween ceiling and shower head, 120v! Keep in mind this is and old house, w/ some knob and tube hidden and alot of bx.

i opened the ceiling light box, of course craked old wires. I repaired/replaced everything in sight, figured that was the issue. Put it all back together and tested the shower head to ceiling, and got continuity. Well i happened to have my hand on the shower head and my other i grabbed shower curtin rod(hung from the ceiling). WOW I was hung up for what seemed like an eternity, thank god she was there and was able to break me off with a broom. I have been hit with 277 and 440, never that bad. Hands are still shaking. Anyhow, i got my volt meter and what do you know, with the light off and box pulled out of the ceiling, i had 47 volt between shower head and and ceiling.

I pulled the floor up in the attic above it, and ripped everything out off the ceiling and tested again, 17volts. Nothing touching the tin ceiling?????? The outercasing of the bx has 47 volts to ground.

Needless to say, now i am rewireing the whole floor, but cant for the life of me figure out why it has only 47 volts.......... i have seen stuff energized w/ 120 when missing a ground and such, but never anything like this. Any suggestions? Anyone ever seen this before? Thanks guys!
 
Generally when water pipes are energized it seems to be due to a faulty neutral connection. The juice is trying to get to "ground" (back to its source) and will seek whatever alternative path is available.

If the service neutral is open and the water pipes are bonded, that is it's logical direction.

Try to isolate it by turning the breakers off one at a time to see if it's coming from a particular branch circuit.



BTW, there have been a LOT of these posts lately. Scarey.
 
I had a similar situation years ago, but they were getting bit from the drain in the sink. Upon questioning the tenant I found out that they recently, 1 week prior, had someone blow in insulation in the attic. There was a K&T wire running just inches from the cast iron vent pipe and the wetness from the insulation created a nice path to the vent pipe. I cleared away the insulation and taped up the K&T, which was in good shape. I then bonded all the cast drains and vent pipes.
 
Generally when water pipes are energized it seems to be due to a faulty neutral connection. The juice is trying to get to "ground" (back to its source) and will seek whatever alternative path is available.

If the service neutral is open and the water pipes are bonded, that is it's logical direction.
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I agree with the above.
 
well, just got down from the attic, weirdest thing. i ripped up most of the floor and started ripping out al the bx and k+t, not finding anything directly shorting, after thinking about it for a while, it has to be the neautral SOMEWHERE in the circuit, but the darn knob and tube is everywhere. I really hate that stuff.

So now with the circuits rewired, bath, kitchen, dining rm and laundry rm, and all the old knob and tube energized (to see where i stand) i am reading 5vac to ground. It seems like every bit of k+t i pull drops that reading by a volt or so. Odd. Guess im going to rip it all out! I cant imagine if the tentant was in the shower and grabbed that shower rod. Man. Some of thee old houses are pretty scarry with some of the stuff they did. I found 1 flying splice odd knob and tube to uf w/ the ground cut, to a buired metal jbox with no cover or connecters feeding out to 18/2 lamp cord running the kitchen lights w/ no boxes screwed to the tin ceiling. In what whose head did that seem like a good idea? No wonder why its energized!
 
I agree also. I have found that when people are getting shocked by the water pipe, it is "usually" a utility issue. Check at the pole or at the weather head and see if you spot anything.
 
Scott, what others have suggested, but not said outright, is that it's the plumbing that's energized, not the ceiling. Look into it again with that point of view, and let us know what you find.

By removing BX, you might merely be weakening the bonding of the ceiling, and not really relieving the actual cause. You need a real earth reference to measure voltages against.
 
LarryFine said:
By removing BX, you might merely be weakening the bonding of the ceiling, and not really relieving the actual cause. You need a real earth reference to measure voltages against.
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Couldn't agree more. I've chased that rabbit more than a few times. Need some earth to make it real.:grin:
 
Yes i thought of that too, energized plumbing, but the plumbing is bonded at the entrance, service bugs are good, i am not reading any voltage anywhere else in the home (2 family, i live on the first flr). Gas hw heater, no elec.

I took readings after i rewired everything i could get may hands on, and i bonded the ceilings, not sure if thats a code issue, but in my mind the safest thing to do here! So, with everything rewired correctly, i still have 4.5vac bettween the bonded ceiling and shower head. ???????? Checked for voltage @ bonding in basement, continuity, no voltage bettween panel ground and plumbing..............i guess im ripping down the walls to rid that k+t too.........
 
did you try killin each circuit one by one till the volts go away? someone else posted that thought earlier and I would do that, then you know what circuit and what is on that circuit leaking the volts...
 
Using originally an ideal vol con, threw that one away and bought a new one (it didnt register the 97 volts that almost killed me!) but now im using my ideal ampmeter/ multimeter, not a cheap one either. A good one, im sure its correct, no doubt in my mind.

Originally the k+t circuit when off cleared the voltage. I cut it back untill i had 0.0vac on the ceiling. I then rewired and feed from the subpanel in the attic (bonded and wired correctly) still had 0.0on the ceiling. energized the rewired circuits and pow 4.5 volts. all plastic boxes and bonded ceilings, all new romex everthing. I cant imagine the plumbing could be energized at only one point, all steel + cu pipe. Dosent make sense. No voltage in the basement to true ground.
 
Killing the main breaker should confirm that it is internal to the house. Just in case you are getting an external feed.

Bonding the tin ceiling is proper, legit, and should be done; Otherwise charge may build up on the ceiling like a capacitor.

Obscure voltage values can show up due to voltage division. Somewhere in the house you may have something acting like a resistive heater.

As recommended by others it is best to go circuit by circuit. At the age of the house do not overlook that two circuits may be cross-connected.
 
Must Be Some House,,,

Must Be Some House,,,

I get the picture of a duplex, but with a 480 VAC service... Seems kinda industrial to me. Is there a 480 VAC service? Is each Tenant's service independently metered?
 
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If the Tin ceiling is bonded and you are still getting a reading between the shower head and the ceiling then that would suggest to me that the plumbing is HOT not the ceiling. You mention a sub panel in the attic, is that a floating neutral or was it also bonded? Also could there be any plastic water lines added between the two floors? Take a reading from a neutral to the water pipe (shower head) and see if you have a reading then. After reading all the posts I still think your water pipe is energized and your chaseing the wrong ghost.
 
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