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dcalabro
Do I Need A Ground Rod

My breaker box connects to ground by a wire connected to nearby copper piping. Do I need to install a new grounding rod or would I get any additional protection if I did?

Brad
Re: Do I Need A Ground Rod

Is the copper pipe connection a grounding electrode connection or just a bonding connection? To be a grounding electrode the connection should be made within 5' of where the metallic pipe enters the structure. And yes, there should be supplemental rods for the service.

dj1
Re: Do I Need A Ground Rod

The last time I ask my electrician this question, he said yes.

Justin Smith
Re: Do I Need A Ground Rod

You need a minimum of 2 grounding electrodes. The water pipe counts as 1, so you need 1 more.

motoguy128
Re: Do I Need A Ground Rod

You can't really have too many. The water service pipe is still the best ground because of it's depth underground. But I'd still want 2 near the box so that you have a localized ground right near the main service entrance. The ground potential can still vary over even a few feet. Additionally, you still want your plumbing grounded... especially if you have copper or galvanized pipes. Although those in old hoses often have a ground for their plumbing already since all the drain pipes are iron.

Funny how a lot of the new and supposedly superior products can often create new issues. With all PVC and plastic pipes, you lose that ability to ground your plumbing. Perhaps it's not needed as much in that case. Personally, I still have doubts that PEX & PVC will last longer than the 86 y/o steel and 65 y/o copper that still in service. We'll see.

Brad
Re: Do I Need A Ground Rod
motoguy128 wrote:

You can't really have too many. The water service pipe is still the best ground because of it's depth underground. But I'd still want 2 near the box so that you have a localized ground right near the main service entrance. The ground potential can still vary over even a few feet. Additionally, you still want your plumbing grounded... especially if you have copper or galvanized pipes. Although those in old hoses often have a ground for their plumbing already since all the drain pipes are iron.

Funny how a lot of the new and supposedly superior products can often create new issues. With all PVC and plastic pipes, you lose that ability to ground your plumbing. Perhaps it's not needed as much in that case. Personally, I still have doubts that PEX & PVC will last longer than the 86 y/o steel and 65 y/o copper that still in service. We'll see.

Bonding the metallic piping systems has nothing to do with grounding. The purpose of bonding is to provide a low impedance path wihich will allow circuit breakers to trip in the event the piping becomes electrically energised.

Re: Do I Need A Ground Rod

If your service entrance panel was connected to the metal water pipe within 5 ft of the point it enters the house and 10 ft of it is in contact with the soil you have one of the best grounding electrodes available.

However, as was mentioned, you still need two more (spaced at least 6 ft apart from the each other), unless you measure you measure the effectiveness of the first rod and it measures at least 25 ohms.

As was also mentioned metal piping and duct work should all be connected by at least #6 copper wire.

Good Luck from Columbiana, Alabama
Maurice Turgeon, http://thesemi-retiredelectrician.com

Fencepost
Re: Do I Need A Ground Rod
The Semi-Retired Electric wrote:

As was also mentioned metal piping and duct work should all be connected by at least #6 copper wire.

Besides water piping, this also includes gas piping and even metal building framing. If there are sections of metal piping separated by plastic, it's necessary to connect each section of metal piping as well.

Maurice, what about dielectric unions? The purpose of them is to electrically separate copper and galvanized steel piping to prevent electrolysis, but it seems that doing an electrical bond as required by the electrical codes would defeat the purpose of the dielectric union (as required by plumbing codes). Are the different codes at odds with each other?

motoguy128
Re: Do I Need A Ground Rod

Good point about ductwork. While the case of the furnace or air handler is usually grounded, that's not a very large ground wire. Probably best to have a separate ground connected to any nearby copper water piping. Probably wouldn't hurt to do this in a couple places where convenient.

I just added another thing to my to-do-list.

Brad
Re: Do I Need A Ground Rod

Please show me where the electrical code requires duct work to be bonded

Re: Do I Need A Ground Rod
brrichter wrote:

Please show me where the electrical code requires duct work to be bonded

552.57

Maurice, what about dielectric unions? The purpose of them is to electrically separate copper and galvanized steel piping to prevent electrolysis, but it seems that doing an electrical bond as required by the electrical codes would defeat the purpose of the dielectric union (as required by plumbing codes). Are the different codes at odds with each other?

Fencepost, the EGC to the water heater effectively grounds it and the dielectric unions protect the water heater piping. I always jumper across the CW & HW piping.

I'm not too familiar with the plumbing codes but they probably do conflict to some degree. A severe ground fault will destroy a cold water line, which seems to bother plumbers.

Look at the Gas Codes...they really don't like electricians bonding to them and will remove them as soon as the electricians leave.

Carpenters don't seem to like what we do to their brand new load bearing joists & walls, probably because they fail their inspections over it.

Sheetrockers have a nasty habit of hiding our boxes, cutting our wires and leaving large gaps around our outlets, which makes us fail our inspections.

Yes, it's a rare job where everyone gets along.

Good Luck from Columbiana, Alabama
Maurice Turgeon, http://thesemi-retiredelectrician.com

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