Shocked by faucet

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Paul B

Senior Member
I just finished an addition on a residense. After everything was done the folks tell me that they are getting shocked off a faucet in the basement shower. The shower has a concrete base on earth. The drain is ABS. The copper pipe in the house is bonded hot and cold the the panel buss. I checked with my meter from the faucet to the panel ground buss and neutral buss and read zero. When measured from the faucet to the hot side on the panel I read 119 on each. I took off my shoe and put my bare foot on the shower floor and touched the faucet knowing fool well I was not going to get shocked and didn't. They swear they get shocked. Got any ideas? Also let me mention they said they have gotten a shock from it long before we did any work there.
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
Re: Shocked by faucet

How frequently do they get shocked? Did you turn on everything you could (bath fans, lights, etc)?

Could it be that the only metallic object after walking around on carpet is that shower? :)
 

pierre

Senior Member
Re: Shocked by faucet

Had a contractor with a similar situation. The dryer was improperly wired and they would receive a shock only when the dryer was operating....may be another item in the home, try energing some and see what happens - use your tester when testing, not your toe ;)
 

Paul B

Senior Member
Re: Shocked by faucet

They say they only get shocked after the shower while turning it off, never when dry. I will try turning on other appliances today. The floor is continuous tile from the bath room to the laundry room and never get a shock from anythiuing else.
 

1madison

Member
Re: Shocked by faucet

I once had a similar proplem.Try disconnecting the bath fan and kitchen exhaust fan if they have one.Good luck
 

monkey

Senior Member
Location
Arizona
Re: Shocked by faucet

"They say they only get shocked after the shower while turning it off"


Is the water heater electric???
 

Paul B

Senior Member
Re: Shocked by faucet

Yes it is an electric water heater. I checked continuity from the faucet to the ground lug in the panel. I read less then 1 ohm. I tried turning on and off various other appliances and it made no difference. If the problem was coming from the water heater, you would think it would be eliminated by the grounds on the hot and cold water lines above the tank.
 

haskindm

Senior Member
Location
Maryland
Re: Shocked by faucet

Try checking from the drain to a known good ground. I suspect you have an energized floor and the voltage is returning to source through the properly bonded water pipes. If this is the case, it may be necessary to tear up the floor in order to bond the steel in the concrete floor. This is similar to some of the cases that Mike Holt has found with swimming pools, where the steel reinforcement in the concrete deck has been improperly bonded or is not present. This led to the requirement for the equipotential bonding grid that extends 3 feet from a pool.
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
Re: Shocked by faucet

Originally posted by Paul B: If the problem was coming from the water heater, you would think it would be eliminated by the grounds on the hot and cold water lines above the tank.
Current will take every available path back to its source. If there is a failure in an electric heating element, such that the current carrying section of the element comes into direct contact with the water in the tank, then current can flow through the water. That could energize any metal component that has a bonding path back to the source.

This concept occurred to me from their description of the times at which they feel the shock. It is at the end of the shower. So I suspect it has less to do with their being wet, and more to do with the fact that the heating element will be energized as the tank's heated water is being used up during the shower.
 

Paul B

Senior Member
Re: Shocked by faucet

haskindm, I tried checking that today it was zero, the drain is metal but the pipe in the ground is ABS.

charlie, I also thought of that today, I ran the laundry tub long enough to cause the heater to heat. I removed the gounds on the hot and cold water lines and checked there, no voltage.
 

Zifkwong

Member
Re: Shocked by faucet

Have the utility check their ground.

This could be "tingle voltage".

How balanced is the panel??
 

monkey

Senior Member
Location
Arizona
Re: Shocked by faucet

Paul, in order to check both water heater elements you will have to run the hot water till you use it all up. Just runnung enough to start the heater only energizes the lower element. The upper element doesn't energize unless the top of the tank gets cold. At that point, the upper element energizes and the lower one shuts off. This is to provide hot water quicker when the supply is depleted. If you never use much hot water, the upper element will never energize.
 

haskindm

Senior Member
Location
Maryland
Re: Shocked by faucet

Monkey,
I think you have it backwards. The upper element energizes first; only when the upper element is satisfied does the lower element energize.
 

monkey

Senior Member
Location
Arizona
Re: Shocked by faucet

haskindm,
You are right, the upper element energizes first when you first start up the water heater. That is because the top of the tank is cold, and the upper thermostat has priority. But when the tank reaches temperature, it is the lower element that does all the normal heating. The hot water is drawn off the top and the cold enters the bottom via the dip tube. Since heat rises, the top stays hot while the bottom cools first from the cold water entering. Thus the lower element will energize most of the time, except when enough hot water is drawn out to close the upper thermostat. So under normal usage and a properly sized tank, the upper element will almost never energize. That is also one reason the lower element usually fails first, plus the fact that is gets buried in sediment.
Brian
 

peteo

Senior Member
Location
Los Angeles
Re: Shocked by faucet

Whether they're generating a static charge or there's current in the earth underneath, either from utility or the house wiring, it seems the next step would be to bond the shower's concrete shell. The problem with this is theoretical, because concrete is a good conductor so shouldn't need bonding to the supply pipes adjacent. Any chance they're in fact standing on a film of sealant, or in a plastic shell, electrically isolated? The plastic sealer they use for factory floors is nonconductive, but still reads 10e3 to 10e9 dry, so makes for a good surface with a ground strap (it takes special equipment to test this.) If it's easy, why not try sinking a lug into the base, then a bonding wire to the supply pipes for a local equipotential plane. If the same thing keeps up, it's highly unlikely that anything in the faucet is building up a charge. Where else could a voltage difference exist...
 

benaround

Senior Member
Location
Arizona
I hope you have told these people not to use the shower until the problem has been solved?

Someone could get killed under these conditions!
 

mjc

Senior Member
Ran into this in the past. The owner was getting a small shock when touching the faucet in the bath-tub. Traced it back to a 120v circuit controling Hi-Hat lighting in the kitchen. the shock was real but only 11 VAC was measured from the faucet to the tub drain. Never did find out why the potetial existed but in the past , the drain pipe was replaced with about a two foot section of PVC , water or the owner would create a path for continuity. I bonded the copper faucet to the copper drain pipe with a piece of #6 and two ground clamps -- the problem was corrected but never popped the fuse. Got paid and everyone was happy.

Good Luck , let us know what you find ... Mike :)
 

Paul M

Member
This is Paul B. I am having trouble logging in so I opened a new account using my work e-mail.

Anyway I have not got back to that site yet, I supposed to go there tomorrow. And yes I did advise the folks not to use the shower.

mjc, what was wrong with the hi hat?
 
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