View Full Version : Water questions for the electrical experts!!!

03-03-2009, 05:54 PM
I posted this in pump, well and water softener forum. They suggested to give electrical a try.
What it boils down to is that I have had 2 problems. First, I have had some blue/green staining from a tub that was slowly leaking. Also, I had a series of pinholes in one of my copper pipes.

The electrical part is that a water treatment guy said he believes that the grounding of the electrical panels to the copper plumbing is causing electrolysis of the copper. There are no water issues such as low ph to contribute to this problem.
One forum member stated that the copper ground is to connect the water pipes to the electrical panel ground in case of electricity contacting the water supply and conducting the whole house. In other words it is a safety item for the whole house.

My problem is the the pipe that gets the pinholes if the one that has a 5/16"
stranded coppper ground wire connected to the electrical panel ground. Why would this happen?
What can be done about it to prevent any more copper pipes getting pinholes?
How can I test for any other causes of electrolysis?

03-04-2009, 03:51 AM
Galvanic corrosion is caused by dissimilar metals touching like iron and copper.

What metal is the ground clamp connecting the ground wire to the copper pipe made of?

Is the pipeline all copper or are there non-copper fittings, hangers, or anything else non-copper touching the copper pipe?

An electrical appliance could be malfunctioning and "leaking to ground". Also there is a thing called a "ground loop". This is a small electrical current which flows between two different ground sources. To find either of these, a qualified electrician could disconnect the ground from the copper pipe and measure between the two with a meter. WARNING! This could be very dangerous if an electrical appliance is malfunctioning as full line voltage could be present between the ground wire and the copper pipe!

Then natural gas companies connect electric wires to their old metal gas lines as part of their "cathodic protection systems". I suppose this could be another source of current to consider if the supplied gas line is metal and is in some way electrically connected to the water line.

Cathodic Protection

Ground loop...

Galvanic Corrosion

03-04-2009, 03:52 AM
Try this (http://images.google.com/imgres?imgurl=http://www.cashacme.com/_images/products/sharkbite/PEX.jpg&imgrefurl=http://www.cashacme.com/prod_sharkbite_pex.php&usg=__yrGdO8w-UlLrNR40Rc7bAVaMUno=&h=300&w=252&sz=14&hl=en&start=16&tbnid=9rmEFY9pwuI-JM:&tbnh=116&tbnw=97&prev=/images%3Fq%3Dpex%2Bplunbing%26gbv%3D2%26hl%3Den%26 sa%3DG) It seems to help

03-04-2009, 08:09 AM
Billy Bob,
The ground clamp is normal ground clamp that appears to be copper or brass. There are no non-copper metallic materials touching the pipe. hangers are nylon.
No utilities , gas, cable connecting to the pipes. The telephone service has a ground rod buried 40 feet away.

I will have an electrician look at it to see if current is present.

Could we ground the pipe to a different ground rod and not connect to the electrical panel and eliminate the ground loop?

03-04-2009, 10:13 AM
Are there any other earth grounds connected to the electrical system? Like in another box or some remote equipment.

Does anything else have a separate earth ground attached? You indicated the telephone system had one 40' away.

Is there a solid ground between the well electrical equipment and the house panel? (look for corroded connections).

Where do you use copper pipe? Is it only inside the house?

When you get an electrician out he ought to be investigating possible ground current paths if he does not find something obviously miswired. Leakage from the pump power. High resistance in a ground connection/wire.

03-04-2009, 11:22 AM
The main panel feeds another panel in the shop 150 feet away the has a ground rod. Recently installed and good condition.

Two wells are attatched to the house by plastic pipe. No ground rods at either pump. They are grounded in the main panel (2x200 amp panels).
The cable from the panels go into the conduit out to the power pole on our property that has the meter on it. It does not have a ground rod that is visible above ground. The electrician who replaced/relocated the panels 3 years ago is very knowledgable and I assume would have verified the ground system.

Copper is only in the house. Plastic to the wells.
Thank you