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Ground rods at light poles

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mayanees

Senior Member
Location
Westminster, MD
Occupation
Electrical Engineer and Master Electrician
I'm involved in a situation where ground rods were specified to be provided at light poles. An inspector has deemed the installation to be non-compliant because it violates 250.53(G) for Rod and Pipe Electrodes because the ditch that the EC has laid the rods in is only 18" deep and needs to be 30" per 250.53(G). I read the section as the rod is required to be driven horizontally or at a 45-degree angle and that if that doesn't work, then in a ditch at 30", but that's for a real grounding electrode.
My contention is that the rods are not required, and therefore they can be placed at the bottom of the 18" ditch. I personally would not have specified rods at light poles per Mike Holt's teachings, but from what I understand the facility wanted them.
So, if the rod is provided at each pole, can they just be laid at the bottom of the 18" ditch that contains the conduits powering the pole light?

Thanks for any responses.
 

Johnhall30

Senior Member
Location
New Orleans, LA
Occupation
Engineer
Yes you are correct, the ground rod is not required unless there is an OCPD at the lighting pole.

It is up to the AHJ whether the supplemental grounding rod is required to meet 250.53, even if it is not required.

If he says he wants it at 30 inches.. then that's what you might have to do to pass inspection
 

Fred B

Senior Member
Location
Upstate, NY
Occupation
Electrician
Make sure you have the EGC back to panel and is required. A ground rod does not replace the required EGC. Simplest is do as infinity suggested just get rid of it.
 

jap

Senior Member
Occupation
Electrician
I would think the job spec is what's going to hold you up.

It's not like we can disregard a job spec requiring a wire type EGC to be pulled even though using EMT is perfectly acceptable.

If the discrepancy was not addressed prior to the install, it would be doubtful you could just get rid of it or not connect it seeing as how it was in the spec to begin with.

JAP>
 

jap

Senior Member
Occupation
Electrician
It's not the inspector's place to enforce a job spec.

If the Facility wanted them, and, they are in the job spec, the enforcer of the job spec is the one to make the decision.

JAP>
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
What's the purpose of the ground rod? If it's lightning protection do the code sections quoted in the OP even apply?
 

mayanees

Senior Member
Location
Westminster, MD
Occupation
Electrical Engineer and Master Electrician
What's the purpose of the ground rod? If it's lightning protection do the code sections quoted in the OP even apply?
The requirement for a ground rod at each light pole is in the job specification, and we wrote the spec, so we are holding the EC responsible to provide it. I agree that it's not NEC-required, but it is in the spec so the EC is required to install it.
I also concur that it's not necessary, and as such could be installed at the bottom of the 18" ditch. But if the client's preference was for ground rods at each pole, I would think their desire was for lightning dissipation, and I think a ground rod driven into the earth would be better at dissipation than one placed at the bottom of an 18" ditch. So we'll enforce per the graphic in NFPA 70. Thanks for the comments. 1665498013162.png
 

AC\DC

Senior Member
Location
Florence,Oregon,Lane
Occupation
EC
It’s a light pole with a concrete base and large j hocks probably. Rods do nothing, the base does more than the rods. Just dump and I feel for the ec
if the specs don’t say how deep or what rod or wire. i would put and do whatever I wanted since its out of the nec requirement.
since it’s not an nec requirement he does not have to follow squat. Drive a nail and attach # 22 if nothing is called out in the plans
 

jap

Senior Member
Occupation
Electrician
It seems the EC did provide a rod a the poles per the spec.

If the spec or a detail on the prints did not indicate how the rod was to be installed, I would say the EC has fulfilled his end of the deal.

JAP>
 

steve66

Senior Member
Location
Illinois
Occupation
Engineer
If the facility wants them, I assume they want them installed correctly.

And if your spec requires a ground rod at each pole, I assume your spec also has specifics on how ground rods are to be installed.

I'd say it's on the contractor to fix.
 

jap

Senior Member
Occupation
Electrician
If the facility wants them, I assume they want them installed correctly.

And if your spec requires a ground rod at each pole, I assume your spec also has specifics on how ground rods are to be installed.

I'd say it's on the contractor to fix.

That seems to be the missing piece of the puzzle thus far.

JAP>
 

mtnelect

HVAC & Electrical Contractor
Location
Southern California
Occupation
Contractor, C10 & C20 - Semi Retired
Just for conversational purposes ... This is what a Public Works installation would require.
 

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Danielt

Member
Location
VIRGINIA
Occupation
Master Electrician
It's not the inspector's place to enforce a job spec.

If the Facility wanted them, and, they are in the job spec, the enforcer of the job spec is the one to make the decision.

JAP>
That's an interesting point, and maybe a new thread. We do enforce job specs, or more exactly, approved plans. If the engineer shows 4/0 run to ground rods, the service isn't passed ay other way, even though a #6 meets code. Or a over-sized conductors to a transformer. Or ground rods at light poles. Plan review make sure the plans meet code, the inspector makes sure the installation is per code and per plan. To not install per plan requires a letter from the engineer/architect.
Plus, the job should have been bid to meet all plans and specs.
 

jap

Senior Member
Occupation
Electrician
That's an interesting point, and maybe a new thread. We do enforce job specs, or more exactly, approved plans. If the engineer shows 4/0 run to ground rods, the service isn't passed ay other way, even though a #6 meets code. Or a over-sized conductors to a transformer. Or ground rods at light poles. Plan review make sure the plans meet code, the inspector makes sure the installation is per code and per plan. To not install per plan requires a letter from the engineer/architect.
Plus, the job should have been bid to meet all plans and specs.

Are you an inspector?

JAP>
 

Fred B

Senior Member
Location
Upstate, NY
Occupation
Electrician
IMO they can add as many unneeded ground rode as they like so long as they don't try to substitute the rods for an EGC at the pole.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
If the facility wants them, I assume they want them installed correctly.

And if your spec requires a ground rod at each pole, I assume your spec also has specifics on how ground rods are to be installed.

I'd say it's on the contractor to fix.
You know what they say about assuming...
I wouldn't be surprised if the spec writer and the EC both made assumptions that were wrong. Fact is, we don't know.

One thing that I wonder... Why did the EC go to all the trouble of digging ditches instead of driving the rods? Or was the dirtch already there?
 

mayanees

Senior Member
Location
Westminster, MD
Occupation
Electrical Engineer and Master Electrician
1665531873327.png
The EC is installing per the spec which called for rods at the poles. They'll be in compliance with 250.53, driving rods vertically, except where rock prohibits, then 45 degrees if vertical doesn't work, and then in a 30" deep ditch as a last resort. You can see from the snip that it's all rock.
 
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