Odd grounding issue...need advise

Status
Not open for further replies.
T

Timco

Member
Hello to all!

I was a sparky for 12 years before going into residential maintenance and being a landlord. We have a 4-plex that was a SF home, built in 1919 and converted in 1940. Each apartment has it's own small sq d sub panel, original. service change about 10 years ago, permitted. After we bought it, I removed a lot of the leaking iron pipe with pex and re-jumped (bonded) the steel pipe to the CW entry and did jump the regulator. No problems until after the neighbor's tree comes down and I can see that the neutral has been disconnected at the pole for years. I call it in and the power company hooks it up, but now one tenant's tub faucet handles are shocking them. I check and jump the pipes leading to the tub faucets to ground (CW entry), and then had to bond to the tub because it was still shocking them but worse after bonding the pipes. Now the tub & faucets do not shock them, but the chrome plated brass soap dish (original) shocks them. I have checked but cannot measure any voltage. Has anyone faced a similar situation? Maybe just replace the soap dish with porcelain and call it good? Lathe & plaster walls...
Thanks, Tim
 
well you have current where current doesnt belong so theres a major problem. turn circuits off until it goes away and go from there. could be a bonding issue, ground fault issue. maybe there is a problem with the drain since you removed a lot of iron and replaced it with pex. current can be on the drainn going to the CW pipe as a path
 
if its metal lathe, the lathe might be energized. it might be energized from one of your neighbor's bad neutrals, not necessarily from yours. the stray current could also cause a fire. you need to thoroughly investigate and pin down the cause. start by turning off all the panels one at a time to see if it goes away, if all are off and you still have a problem, it is on other side of poco.
 
Well let's see, you had current from the tub to the handles until you bonded the tub but now have current from the soap dish to the tub and handles. On the opposite side of the wall is there an outlet that may possibly have defective wiring and is energizing the lath in the wall? Could have lost the ground in that box and that could be energized and making contact in the wall with the lath. It is old so who knows. If there is an outlet then turn that circuit off and see if it disappears.

Also, determine if there is any wiring in the affected wall if there is no outlet but just a cable passing through the wall in that area. Test the soap dish to an outlet ground to see how much voltage is there.
 
Last edited:
Thanks for the ideas. Building is wood lathe. I was thinking maybe some DIY guy put in a grounded receptacle and in an attempt to get ground jumped the neutral to the ground and the box was grounded to the pipes or something but the soap dish??? First I need to figure out the perfect storm of lights being on or things plugged in to get a reading, then I will kill panels. I just can't figure out why it was fine until the neutral was properly hooked up at the pole. I have seen dozens of neutral problems and this is really strange because if the tub, drain & H/C W pipes are bonded, then the soap dish must be energized. If the CW service was not a good ground, I would have had major problems with no neutral all these years. I have owned it almost 5 years now...and I will get to the bottom of this because I really do take it seriously...nothing worse than a dead tenant or burned building.

Thanks again, Tim
 
Timco said:
Building is wood lathe.
Click to expand...

Yes, wood for the plaster walls but if the tile is original it is common to find steel lath in behind the tile unless they were all gutted and replaced. Could also be as simple as the soap dish mounting screws piercing a wire in the wall.

Just throwing things out there as I don't know the situation from the limited information.
 
Now THAT is some good thinking...the steel lathe behind the tile! Danialson, you must sometimes think like a tile guy to be a electric guy...you must BE the wire...

Lots to check into Monday, thanks to all. I will report back.

Tim
 
Usally long screws in tub area causes electrical problems. I would like to add a code in the nec to forbid running of elect wires in tub area at next cmp if possible have seen multiple situations from bad plunbers running 3" deck screws into feeder cables.
 
Tim, welcome to the forum! :smile:

Keep in mind that a shock occurs because of contact with two different surfaces with a voltage between them, but it doesn't necessarily tell you which surface is hot, relative to the earth. A non-contact tester might be a help here.

I recommend plugging a 3-wire extension cord into a known-properly-wired receptacle, and taking the female end with you into the bathroom, and testing these various conductive surfaces against all 3 slots with a solenoid-type tester.
 
Smart $ said:
Please use a GFCI-protected receptacle or ext. cord.


Ditto on the welcome ;)
Click to expand...

LarryFine said:
Won't work; the wiggy will trip the GFCI.
Click to expand...

electricalperson said:
if you use a high impedance tester it wont trip but you might get ghost voltage. a wiggy is the best thing to use
Click to expand...

That wasn't his point, it was not to use a GFI protected cord during the test as it would trip with the wiggy. The low impedance tester is the best to use in this situation.
 
i also have had a simular issue there was a inconsistant 100+volts from the tub drain/faucet and the toilet stud we disconnected each branch circut from the panel (hot and neutral) till voltage was gone then we disconnected each section of the branch circut starting from the end of circut till we found the section that was causeing the issue we reran a new wire and all is well. however since we never removed the old wire and there is no plumbing near the wire we replaced the issue was fixed but never resolved
 
Timco said:
I have checked but cannot measure any voltage. Has anyone faced a similar situation?
Click to expand...
This worries me. Without being able to measure you cant analyse, and thus you're in the field of guesswork and this could end up being a very long job.

If a high resistance meter doesn't show a shocking potential, then it isn't a potential difference there and thus the tenant isn't getting shocked. Check on DC range as well as AC... If the tenant gets shocked when touching something then have him hold a meter probe and touch the something with the other probe.

This is an "In Fluke we trust" issue. If the meter says theres nowt there, then theres nowt there.
 
NEC no cigar

NEC no cigar

quogueelectric said:
Usally long screws in tub area causes electrical problems. I would like to add a code in the nec to forbid running of elect wires in tub area at next cmp if possible have seen multiple situations from bad plunbers running 3" deck screws into feeder cables.
Click to expand...

I know what you are saying. [300.8] is trying to say this but doesn't address the stayout location like you are mentioning.
300.8 Installation of Conductors with other Systems.
Raceways or cable trays containing elelctrical conductors shall not contain any pipe, tube, or equal for steam, water, air, gas, drainage, or any service other than electrical.

Electrical installations running through plumbing core locations is just asking for failure. Wires get cut and holes blocked when other trades get territorial about wiring in the way. The verbiage of 300.8 is not very effective toward safe integrating around stay out areas. rbj
 
Status
Not open for further replies.
Top