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Telegrapher
Cold water pipe ground

My 50 year old house uses a cold water pipe for the electrical ground. I need to replace that cold water pipe and am concerned about removing the ground while the plumbing work is being done. What do I need to know to safely complete this repair? Thank you.

kentvw
Re: Cold water pipe ground

It may very well be that you are grounding the electrical system via the cold water pipe. However, you are also bonding the piping to to the neutral in the electrical system to keep it at the same potential and providing a path to the neutral.

Is this the only ground? Or do you have a ground rod under the meter and or panel outside? I would think you would have a ground rod. If that is the case and your not going to have use of the plumbing while it is replaced and I would not be too concerned. After all, Homes around the world are being built and plumbing is being installed with out the piping being either used for a ground or being bonded to the electrical system.

Telegrapher
Re: Cold water pipe ground

The electrical panel is grounded to the cold water pipe only. I see no ground rod connection outside at the meter. Tks.

Anonymous (not verified)
Re: Cold water pipe ground

Drive a ground rod . Make a parallel connection to the existing ground . Lift the connection to the water pipe . Make your repairs . Have a good day .

Telegrapher
Re: Cold water pipe ground
Sam wrote:

Drive a ground rod . Make a parallel connection to the existing ground . Lift the connection to the water pipe . Make your repairs . Have a good day .

Thank you. Do I connect the ground rod to the point on the service panel where it's presently connected to the cold water pipe? Do I run the ground cable to the ground rod in conduit (it has to go through the building)? What gauge wire is required for the ground?

kentvw
Re: Cold water pipe ground

Do you have a main breaker? What size is it?

This info will determine ground size.

Telegrapher
Re: Cold water pipe ground
kentvw wrote:

Do you have a main breaker? What size is it?

This info will determine ground size.

Yes, the main breaker is 100 amps. Doesn't length of the wire play a factor in determining the proper gauge? Tks.

kentvw
Re: Cold water pipe ground

Not much need to worry about voltage drop on the ground wire.

You will need # 8 solid copper and #8 needs to be sleeved in conduit where exposed outside. I would recommend you use PVC type conduit. If you use EMT you will need to bond the end of it with a clamp made for that pupose.

And yes the new ground will connect at the same spot your other one is in the panel.

djohns
Re: Cold water pipe ground
YukYuk wrote:

Please explain why you couldn't just turn off the main breaker at the box, disconnect the ground strap, do the plumbing work, then re-attach the ground strap and turn the main breaker back on. Why wouldn't this work or be safe?

Sure , you could that . Or , you could go ahead and make the " improvement " . Either way .

Telegrapher
Re: Cold water pipe ground
djohns wrote:

Sure , you could that . Or , you could go ahead and make the " improvement " . Either way .

I thought if you turn off the main breaker and disconnect the ground, you still have an ungrounded service panel with power inside it. Is this a safe option?

djohns
Re: Cold water pipe ground

If the power is off ( main breaker or fuses ) , there will be no current flow . Lifting the ground connection will be OK .

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