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Strange Grounding Configuration


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I had a mid to late 50's ranch today that was "grounded" by a driven metal rod which was connected to the neutral at the service drop with a #6 insulated conductor. Since I have not ever seen this done in nearly 15 years of inspecting I assume that it is wrong.

The original ground connection was to the galvinized water piping which has been replaced with CPVC.

Would one of you guys or gals that are more knowledgeable than me on electrical issues confirm or deny my assumpition?

Thanks ya'll.

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I couldn't find anything against it in the NEC...just that the connection to the grounded service conductor must be on the supply side of the main disconnecting means.

The AHJ might have a problem with those plastic ties used to secure the GEC.

Marc

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I couldn't find anything against it in the NEC...just that the connection to the grounded service conductor must be on the supply side of the main disconnecting means.

The AHJ might have a problem with those plastic ties used to secure the GEC.

Marc

Neverassume anything. Seldom done or seen but it is code compliant.

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I couldn't find anything against it in the NEC...just that the connection to the grounded service conductor must be on the supply side of the main disconnecting means.

The AHJ might have a problem with those plastic ties used to secure the GEC.

Marc

Thanks Marc. It's such an eloquent solution to grounding of homes of this age and earlier that I am surprised that I have never seen it before.

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Eloquent? I think it's a waste of wire. The panel is much closer to the ground rod than the weather head.

Marc

Not in this case and not in this area in general. The panel is located in the center of the house so the grounding conductor would have to run down to the crawl space then 2 feet to the exterior.

Whith the weather head connection it's a 10 foot run plus the ground rod is now located near the phone and cable for easy bonding.

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How far into the house is the panel? Sounds like an extterior disconnect would be required as the unfused cable is not as short as practical.

You're right. Since it was a 60 year old house I told them it had to be torn down becuase it does not meet current codes.

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How far into the house is the panel? Sounds like an extterior disconnect would be required as the unfused cable is not as short as practical.

You're right. Since it was a 60 year old house I told them it had to be torn down becuase it does not meet current codes.

Very clever of you. What was their reply to you?

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  • 2 weeks later...

How far into the house is the panel? Sounds like an extterior disconnect would be required as the unfused cable is not as short as practical.

You're right. Since it was a 60 year old house I told them it had to be torn down becuase it does not meet current codes.

Very clever of you. What was their reply to you?

The buyers were impressed. They felt like they got their monies worth out of me.

I just had an epiphany. Here's my new business model. Just look up the age of the house in the tax records. If it's more than ten years old send an email that says it does not meet current building codes and needs to be torn down. I bet I could do fifty of these before lunch and never leave the office.

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  • 4 weeks later...

This will probably get to you too late to be of benefit, but I hope not. If I understand you correctly, the main grouding electrode conductor (gec) has been disconnected due to the installation of plastic plumbing. If there is still metallic water piping in the house, 5' or more in length, then there must be a gec run to it from the panel. The neutral conductor can be connected to the ground conductor at only one location at the building. What your picture shows is actualy redundant; the power company has done this at their transformer. This "ground" wire is now a parallel neutral conductor and as such is undersized and dangerous.

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This will probably get to you too late to be of benefit, but I hope not. If I understand you correctly, the main grouding electrode conductor (gec) has been disconnected due to the installation of plastic plumbing. If there is still metallic water piping in the house, 5' or more in length, then there must be a gec run to it from the panel. The neutral conductor can be connected to the ground conductor at only one location at the building. What your picture shows is actualy redundant; the power company has done this at their transformer. This "ground" wire is now a parallel neutral conductor and as such is undersized and dangerous.

I don't follow. The ground conductor at the weather head is connected to a grounding electrode. Redundant? Electrically, yes, but the code wants a local grounding electrode to serve the building that's separate from the utility's grounding.

What am I missing?

Marc

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Originally posted by Ed Holt

This will probably get to you too late to be of benefit, but I hope not. If I understand you correctly, the main grouding electrode conductor (gec) has been disconnected due to the installation of plastic plumbing. If there is still metallic water piping in the house, 5' or more in length, then there must be a gec run to it from the panel. The neutral conductor can be connected to the ground conductor at only one location at the building. What your picture shows is actualy redundant; the power company has done this at their transformer. This "ground" wire is now a parallel neutral conductor and as such is undersized and dangerous.

I don't follow. The ground conductor at the weather head is connected to a grounding electrode. Redundant? Electrically, yes, but the code wants a local grounding electrode to serve the building that's separate from the utility's grounding.

What am I missing?

Marc

You are correct. The more electrodes connected to the service neutral the better. Mettalic water pipe, rods, ufer, plates, etc.

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This will probably get to you too late to be of benefit, but I hope not. If I understand you correctly, the main grouding electrode conductor (gec) has been disconnected due to the installation of plastic plumbing. If there is still metallic water piping in the house, 5' or more in length, then there must be a gec run to it from the panel. The neutral conductor can be connected to the ground conductor at only one location at the building. What your picture shows is actualy redundant; the power company has done this at their transformer. This "ground" wire is now a parallel neutral conductor and as such is undersized and dangerous.

A metal water line that has been changed over to plastic would not require grounding or bonding. The NEC says metallic systems need to be bonded.

Only if the metal water line was 10' or more in direct soil contact could it be considered an electrode and could be used for grounding. It would still require a supplemental electrode such as a rod.

The neutral is only bonded to ground at the first means of disconnect.

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