Voltage on water pipe

[rookie4now]

I got a call yesterday from a guy who says he gets "a tingle" everytime he touches the faucet in the bathroom. It is a commerical building and this is the only place it is happening (other bathrooms are OK).

Normally I would suspect a high resistance neutral, but that would normally cause any of the piping to be affected.

Is it possible that the circuits in the bathroom have an open neutral and the current is returning via the water pipes? It seems that if this were the case, in order to get zapped (tingle) the water pipes would also have to be poorly bonded.

Any ideas?

 

[dlhoule]

Where are the water heaters located? Are they electric? If a heater has gone to ground he may be providing a parrallel path for current.

 

[ktollar]

water

water

loose ground at water heater

 

[bkludecke]

Welcome to my world. I agree that it may be in an elect water heater. But it could be many other things. First check all of the grounding & bonding issues at the service & panelboards (especially the service bonding jumper). Also it could be that the problem is a POCO neutral issue in the neighborhood. It is hard to tell which direction the current is coming from. I had one of these that caused a shock with the service disconnect open! Also if you check for current/voltage by running water over your hand at a sink, try it with your fingers parallel to the water flow, they are much more sensitive that way.

Bob on the left coast

 

[rigdog]

voltage on water pipes

voltage on water pipes

Possible bad element in electric water heater. :?:

 

[77401]

I'll put my bet on the POCO Neutral Problem. the potential at each bathroom should be different and thats why they are not getting the same tingle everywhere.

Let us know the verdict

 

[kbsparky]

Try shutting off all the power in the building, and see if the stray voltage is still present. IF so, then it's time to call in the power company to try and trace out the source. No use in wasting time if the source is outside of your building.

IF NOT, then restore power to your circuits one at a time to determine your culprit. Then start from that offending circuit to determine where it's leaking from.

 

[paul]

My first thought is also a neutral problem with the POCO transformer. Check to see if any others on that xfmr are having similar problems.

I had a similar call years ago, where the customer was getting a jolt from their bathroom sink. After crawling under the house and finding nothing, I started quizzing the homeowner. They recently had blown-in insulation installed in the attic. This was a K&T house. I climbed in the attic and found a hot wire about 4" from the vent pipe (cast iron), buried in insulation. The insulation was still wet and voltage was leaking through to the vent pipe. I cleared the wet insulation away from the wire and then went back under the house an installed a bond wire to the drains to help prevent this from happening again.

Anyway...grab your meter and take readings from the plumbing fixture to the nearest recept. Check from the fixture to hot, neutral and ground. This should help you trouble shooting it.

Goodluck

 

[e57]

The guy gets a tingle everytime he touches the plumbing fixture.... What else is he touching to get the difference in potential? Maybe that - what ever it is, is hot? It's like saying, 'I get shocked by the floor when I'm standing there barefoot on the concrete with this 3/0 feeder in my hand.'

Years ago I had a call to a resturaunt where dishwashers were getting shocked by the sink.... Turns out the metal wall liner had been screwed through a cable, it was the walls at 120, not the sink! Worse the dishwasher had a fault on an opposite phase, touch the wrong thing in there and you really got hit.

 

[Jim W in Tampa]

My first thought is also a neutral problem with the POCO transformer. Check to see if any others on that xfmr are having similar problems.

I had a similar call years ago, where the customer was getting a jolt from their bathroom sink. After crawling under the house and finding nothing, I started quizzing the homeowner. They recently had blown-in insulation installed in the attic. This was a K&T house. I climbed in the attic and found a hot wire about 4" from the vent pipe (cast iron), buried in insulation. The insulation was still wet and voltage was leaking through to the vent pipe. I cleared the wet insulation away from the wire and then went back under the house an installed a bond wire to the drains to help prevent this from happening again.

Anyway...grab your meter and take readings from the plumbing fixture to the nearest recept. Check from the fixture to hot, neutral and ground. This should help you trouble shooting it.

Goodluck

Hope you also told them that the insulation is a violation and needs removed.