Getting Shocked at Sink

[1902crandall]

Hello- I seem to have some stray electrical current in my sink drain pipes. When I turn the sink on I get a noticeable shock from the water. The shock only occurs when I've let the water run for a few seconds, and only when the water is flowing through the pipes.. no shock if i put a bucket under the faucet. I opened up the wall to test the voltage on the cast iron down pipe and get about 25 volts, and no voltage on the copper plumbing. Also there is about 3 feet of ABS drain pipe between the sink and the cast iron pipe. I am assuming that there is an electrical short somewhere along the cast iron pipe and when the water is running through the ABS pipe it jumps from the cast iron through the flowing water to the sink , and then goes to ground through the copper plumbing. My problem is tracing the source of the electricity. I have narrowed it down to one circuit breaker, but that's as far as I get. Any tips on how to trace the stray current, or ideas of what is going on would be greatly appreciated. Thanks in advance. John

[RBM]

Check, or have an electrician check the grounding system on your electric service. If it's installed properly and intact, this shouldn't happen.

[Rudy]

Metal Plumbing is/was often used as a ground. Perhaps the ground wire from the pipes has come undone. You might look down in your basement/crawlspace and see if there is a clamp around the pipes w/o a nearby wire attached. Its been done that some folks wire their washing machine by twisting the white neutral wire along with the green ground because they only have a 3 prong plug. That could be the source of the stray current.

[m Ransley]

You have a bad short, probably costing you 10-20$+ a month, if you have a ground strap on your pipes dont play around testing removing it unless you Know what your doing and you dont. Id suggest an electrician will fix it safely.

[hallerb]

first whats on the effected breaker? things like washing machines can be responsible.

make a list of everything on the breaker, then unplug everything see if the voltage goes away?

if it goes away plug in one item at a time, and try to find which item causes the problem.

if the voltage is there with nothing plugged in it can still be fixed but will more challenging

[Art]

To clarify, you have a short and inadequate grounding system. If the ground system was right the short would trip the breaker. It isn't doing that so you may have a dangerous situation in the house. Since you don't seem to know much about electricity, get some one to fix it that does.

[Jimmie D]

Ground is only part of the problem, you shouldnt get shocked even if the ground is bad. To which breaker did you narrow it down? I had something like this happen an found my garbage disposal was not GFCI protected. new garbage disposal and replacing the existing breaker with a GFCI type cured the problem Oh yes the ground was open at the disposal. I hate to think these electrical connections had been made by an eletrician. The plumbing under the sink wasnt any better. Probably same guy did both.

[trader4]

A short will only trip a regular breaker if it exceeds the current rating. He could easily have a short of 100ma to ground, which can still kill, but not trip a breaker. It would trip a GFCI, but not a regular breaker.

[hallerb]

Since the OP knows what breaker is causing it basic troubleshooting by unplugging everything on that breaker to see if it goes away is a good first step useful info for a electrician if they are needed.

Say the washer causes the trouble, then its time to get that appliance serviced somehow

[Autumn]

I had the very same problem with my washer. I would be loading clothes in it with the water running and after running awhile it would give me a shock if I put my hands in it.

We had the washer tested and the grounds tested more than once. Had new grounds placed on the whole house. No one could figure out what it was, two electricians, and one washer repair man. I made sure I had tennis shoes on when I washed clothes and kept my hands out of the water. What else could we do if the professionals could not figure it out?

When the well pump went out we finally figured it out. The submerged pump housing had vibrated against the well pipe 78 feet in the ground for years and finally eroded a hole in the housing. Whenever the pump went on it sent a shock up the 78 feet and along the metal pipes into my washer. This would take a little while because the water pressure tank holds some water and until it ran out and the pump came on the current was not there.

The new pump has a special rubber ring around it that prevents the housing from hitting the pipe.

Don't know if this fits your problem, but it may have gone on for years with no one able to find it had the pump not gone out.