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I recently accidentally knocked the ground clamp off of one of my two ground rods with my lawn mower. This rod is the one connected to the water line, not the one connected to the main service panel.

I had an electrician come out and he (understandably) would not replace the clamp because the rod is from the builder in the 80's and isn't up to current code. So now I am in a dilemma that I need to re-ground my plumbing, but I don't have a suitable grounding rod installed.

I know that for a new install, DIY is not an option unless you are licensed. This is a replacement. I would like to fix this myself. I am in Texas. I realize I have to follow the NEC.

I believe that fixing an existing install should be no more difficult than removing the old rod, installing the new one nearby, and attaching the ground wire from the plumbing.

The new rod will be 3/4" x 10 feet. The old rods are 1/2" x 8 feet (or shorter). I am not planning to replace the rod near the service panel myself, I will call an electrician for that. The service panel's rod is at least 40 feet from the rod I would like to replace, so I am well beyond the 20 feet minimum requirement of the NEC for 2x 10' rods.

Does the wire from the plumbing have to be upgraded as well? It's original and runs through the brick, and is a #8 (measured by my wire stripping tool). I believe the NEC requires #6 now for new installs and retrofits, but since this is not a new install or retrofit, I am not clear on the requirement.

I'd also like to confirm if there is anything else I am missing, unaware of, or just plain wrong about?

Any input is appreciated.

  • Why would the existing rod itself not be to Code? What size is your electrical service, for that matter? – ThreePhaseEel Jun 19 '20 at 0:02
  • It's too narrow for today's code which requires 3/4" rods. Both existing rods are 1/2" rods with a length of 8 feet at most. Probably less according to the electrician, because the area we are in was unincorporated in the 80's but is now annexed into Houston. – Speeddymon Jun 19 '20 at 0:06
  • The requirement is either 5/8" or a listing for the rods -- is there a UL mark stamped on the rod itself? – ThreePhaseEel Jun 19 '20 at 0:26
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    Not sure what code requires a rod for pipes, satisfying the NEC normally requires two rods connected to the service panel, and also a wire connecting metal water pipes to the electrical service. – NoSparksPlease Jun 19 '20 at 1:20
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    No, if there's a single 150A main breaker, that's enough information for our purposes – ThreePhaseEel Jun 19 '20 at 3:54
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Maybe the electrician wouldn't just pop a clamp on there because there is too much not seen to the eye, he was confused, and didn't want his license to be on the hook without opening a big can of worms. (Also it looks like you may have some solar equipment, and that may be over his head or license.)

I would expect to see the water pipe bonded and two ground rods connected with #6 bare copper wire for a 150A service. The wire to the water pipe needs to be connected within 5' of where it enters the building. I would call the local inspector and ask if local ordinances requires the ground rods be further separated than the 6' required by the (2017) NEC. One jurisdiction I have worked in required 16'. It is acceptable to run separate Grounding Electrode Conductor (GEC) to each electrode. Usually you loop the GEC through the connector at the first ground rod and extend to the second. Then a separate wire is run to the water pipe, but you could extend the wire from the rods to the water pipe or pipe to a rod. Generally the conductors need to be continuous or spliced with irreversible connection. I would only use ground rods with a (UL or other) Listing mark.

Now some explanation and disclaimers. An unaltered system is legal as long as it was legally installed when installed. The open question that is left to local interpretation is "when does a repair or addition trigger the requirement to bring something up to current code?" So any advice here may exceed the minimum work you might be able to get by with, but will reflect what most electricians would expect an Inspector would expect to see. A local jurisdiction would likely require updating with the addition of solar equipment.

The cold water pipe used to satisfy the Grounding Electrode requirement. Then the Code was revised and said a water pipe needs a supplemental grounding electrode, which for most purposes means a ground rod. This is likely what was required when your electrical panel was installed. Then the Code writers decided that ground rods had to test 25 ohms or less to ground or a second ground rod at least 6 feet away is required. Also Communication systems, lightening arrest, and other systems need to be connected to the Grounding Electrode System, the methods have evolved also, and the NEC hasn't always been adopted or enforced by local jurisdictions or even interpreted the same. Sometimes a 5 ft. ground rod has been driven to satisfy those systems, but they don't satisfy the requirements for your electric service. A fuller mostly accurate description of current requirements for ground rods can be found here. Currently most jurisdictions have adopted the requirement of a Intersystem Bonding Termination for new services, you likely do not need to worry about that.

  • Ok thanks. Yes we did add solar in 2018, but no update appears to have been required to the existing system. I wonder if the inspector for that addition made a mistake though because the Electrode near the service panel and solar transformer is only connected to the coax system, while the service panel itself really appears to be grounded through the plumbing's (single) ground rod. I'm going to call our solar installer to ask their electrician to come look at this. Thank you for that tip regarding the difference in licensing. – Speeddymon Jun 19 '20 at 17:01

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