grounded to water lines

[tvjerry]

We recently had water utility workers replace part of our water service in front of the house (where there?s no electrical wiring). They had arcing that resulted in spikes in our service that caused more than $1600 damage (variable speed motors, dimmers, etc). They claimed it was because we had the electrical system grounded to our water lines, but I talked to several people (electrician and general contractor) who said that was common and acceptable.
We had the local power company come out and confirm that the line was neutral coming and leaving the house. Also, we have a ground rod driven into the ground.
I?m trying to get some official documentation confirming that we were NOT at fault for grounding the system to the water lines. We?ve been told they should have turned off the power to the house as soon as they saw the arcing, but they were negligent. Any support will be helpful in our fight against City Hall.

 

[charlie]

Re: grounded to water lines

Yes, your electrical contractor was required to connect to the incoming water line. Also, your electrical contractor was required to install one additional grounding electrode and (depending on the circumstances) two grounding electrodes.

If you wish to read more about these requirements, go to the library and read 250.50 through 250.56 in the current National Electrical Code (probably 2002 Edition). Better yet, rely on your licensed local electrical contractor.

 

[petersonra]

Re: grounded to water lines

I think you will find it diifcult to get the city to pay for the damage. You would need to pay someone to find out just what happened, and produce some kind of report.

best bet is just turn it over to your insurance company, and forget about it. thats what you pay them for. let them deal with the city if they feel its worthwhile.

 

[tom baker]

Re: grounded to water lines

Its sounds like either you or you neighbor has a open neutral.
the ground rod you installed will do nothing for this problem.
have a qualified electrican inspect your wiring, it could even be a faulty element in your water heater (if electric).

 

[karl riley]

Re: grounded to water lines

I agree with Tom. Did the utility check the impedance of their service neutral connections? (corrosion, looseness). They need to disconnect the grounding electrode conductor to the water pipe to test their neutral.

They would not have to do this disconnection if they simply put a clamp-on ammeter on their neutral and then on the GEC to the water pipe to compare the relative amps/impedances. I don't think they have learned about this test yet.

The water pipes are a parallel path for the neutral current returning from the building to the transformer. If you have a bad neutral connection, or even an open neutral, cutting into a water pipe can be deadly. Many water company workers put jumper cables across the pipe before cutting.

Karl

 

[tom baker]

Re: grounded to water lines

Mike Holts office has a video you can purchase called City or Miami Open Neutrals. Its an eye opener. Note the conditions in the video and from the orginal post only occur with metallic water service lines.

 

[william runkle]

Re: grounded to water lines

Question what type of service panel do you have? And how old do you think it is? Then have your electrician use his amprobe on the incoming legs of power the 240 volts subtract the smallest from the largest and you get an unbalance number that should go through the neautral then check both E.G.C.s one to water source the other to the ground rod and if you get anything on either of those you will have an isolated neautral in your power company sounded like they already have checked their neautral connection. I believe when your water was disconnected you lost the path for the neautral return. I had a situation in Niles Mich. where the city water meter is in the yard and they were going to change the meter they started to remove the old meter and it began to arc so they slam the old meter back in to stop the arc and told the property owner to fix their electric problem at once or risk loosig all utilities. So got to the house check amperage on E.G.C. found to be about 6 amperes so changed out to a new panel and it took care of the problem. I will not say who the manufacturer of this panel but I had three others do the same thing and I suspect another one is already affecting an area giving shocks of eighty volts to the neighbors read the posting where is this power coming from. And if anyone else out there has had an isolated neautral problem panel please post.