Sparks at the Water Meter
We had some plumbing work done today, which required the plumber to disconnect the water meter. As the plumber was re-connecting the meter, he noticed some sparking between the house-side pipe connection and the meter. What could cause this? Is it dangerous or will it cause problems such as pipe corrosion? What is the likely problem and solution? Thanks.
Re: Sparks at the Water Meter
Good motning Harp, You have a problem that must be looked at as soon as possible. It's called "electrolysis" and if not corrected will eat holes in your pipes. Electrolysis is caused when there occurs a short between the electrical system and the house piping. I have tracked a complaint back to a drywall screw that hit a wire and then touched a pipe. After some time tiny pinholes began to appear in the copper house piping. Call around to electrical companys and ask them if they have the equipment and experienced help to locate and correct the situation. Sometimes it's as simple as running a earth ground on your water system. Good luch, Tom
Sparks at the Water Meter
Thanks Speedball,
I will have this looked at.
Just to note, I don't think my water pipes are currently connected to my electrical system ground. Is this an electrical code requirement?
There is a ground wire coming from my electrical service entrance hanging loose and un-connected near some water pipes. This ground wire has what looks like a pipe clamp connected to it. We have had several rounds of remodeling in this house, and, if this is the pipe ground, it may have been disconnected at one point and never re-connected.
The electrical system is grounded via a ground rod.
Should I re-connect the loose ground to the water pipes?
If there were a short of a hot wire to one of the water pipes somewhere, I would think that re-conecting the pipe ground would cause the breaker on that circuit to trip. This would help confirm/isolate this problem.
What do you think?
Harpman
Re: Sparks at the Water Meter
Before making such a connection, I would check for voltage between the pipe and ground wire with a multimeter, test light, or simply seeing if you get a spark. If so. I would work through retesting it shutting off one breaker at a time. If you find a breaker that eliminates the voltage or spark, go over that circuit very carefully. Maybe even disconnect the different branches and try to locate where a hot wire is leaking to your plumbing. If you don't find anything, cal in a professional electrician. He will have one advantage over Tom and I, he will know what local codes call for.
Sparks at the Water Meter
Labman,
I did test the voltage between the water pipes and the electrical system ground. There was some voltage, but not a lot. The voltage difference was pretty steady at about 40 mvAC.
I temporarily connected the electrical system ground to the water pipes and none of the breakers tripped.
I don't seem to have a life-thretening situation, but I will get an electrician in to check the whole system and properly re-connect the water pipe ground if that is necessary.
Thanks for the help.
Harpman
Re: Sparks at the Water Meter
Unpowered wires running along with ones with currents will develop slight currents. I guess a pipe could too. Are there any places where your pipes and wires run close together? It could be enough to give the 40 mV. In that case you could safely ground it and avoid the electrolysis Tom warned you about. It is nice being able to piece the problem together where we can work together and respect each other.
It could also be a short to the ground side of a circuit. Electricians regard water pipes as the gold standard in grounds.
Years ago, we did that a lot on the dog board on the old AskMe, but the idiots ruined everything long before it was shut down. I miss frequently working with other good people. Nobody has all the answers.
Sparks at the Water Meter
Hi Harp, I have a problem with seeing a spark in the microvolt range. Are you saying you measured forty thousandths of one volt and got a spark? I can believe 40 vac but any measure back to earth ground from a plumbing system is unacceptable and should be looked after at once. I would reconnect the pipe clamp with the ground wire. Cheers, Tom
Re: Sparks at the Water Meter
The idea of 40 mV making a spark you could see was bothering me too.
Re: Sparks at the Water Meter
Speedball and Labman,
Thanks for all you help on this. I've scheduled an electrician to come out and check the whole system.
I just checked the voltage between the pipes and the electrical system ground again. It was jumping around quite a bit, but definitely less than 100mv.
The sparks we saw at the water meter were small, more like what you would see with a static electric charge. But they were definitely there, and I guess that is reason enough to get the system checked.
Thanks Again,
Harpman
Re: Sparks at the Water Meter
Guys, I'm sorry?? But a mvolt,(microvolt) is NOT one thousandth of one volt. It's one millionth of one volt. Got to be one real small spark. I apologize for giving out wrong information but what the hell, I'm just a plumber
Sparks at the Water Meter
Speedball,
Actually, a mV is a milli-volt, or 0.001 Volt
I doubt the average homeowner has access to a meter that would measure in the micro-volt range.
Just my two cents worth.
Re: Sparks at the Water Meter
Me bad :o I was right the first time mvolt= millivolt so he got a spark from forty thousandths of one volt. I apologize for the confusion. I mistook mvolt for microvolt. :-[ Boy! Is my face red!!
Re: Sparks at the Water Meter
Milli, micro, nano, kilo, giga, tera... who can keep track of them all! :-/
I too wondered about getting a spark from 40 mV, or 100 mV for that matter. I don't think there's enough energy there. Perhaps there's a physicist in the crowd who can shed some light.
Al