250.53(b)

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chris kennedy

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Miami Fla.
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60 yr old tool twisting electrician
Could someone give me an example of where this article might apply?

250.53(B) Electrode Spacing. Where more than one of the electrodes of the type specified in 250.52(A)(5) or (A)(7) are used, each electrode of one grounding system (including that used for air terminals) shall not be less than 1.83 m (6 ft) from any other electrode of another grounding system. Two or more grounding electrodes that are bonded together shall be considered a single grounding electrode system.
Where would you be that close to another grounding system?
 

480sparky

Senior Member
Location
Iowegia
Maybe when the phone or cable company drives their own ground rods? Or a lighting rod system.
LighteningSmiley.gif
 
One, but not limited to, as stated in 250.53(B) electrodes connected to air terminals for lighting protection, another is when supplementary electrodes 250.54 are installed. Same requirement in 250.56 for spacing of additional electrodes.

Some articles say electrodes should be separated by a distance equal to the length of the electrodes used (ground rods). This is from articles I have read. I have no information to support this information.
 

chris kennedy

Senior Member
Location
Miami Fla.
Occupation
60 yr old tool twisting electrician
another is when supplementary electrodes 250.54 are installed. Same requirement in 250.56 for spacing of additional electrodes.

Wouldn't those be a single grounding electrode system? I think 480 and yourself are on the right track with the lightning protection thing.
 

Dennis Alwon

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Chapel Hill, NC
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Retired Electrical Contractor
How about when a piece of equipment requires an isolated ground rod? Wouldn't that fit the articles description.
 

chris kennedy

Senior Member
Location
Miami Fla.
Occupation
60 yr old tool twisting electrician
I installed a second service of different voltage and phasing to a building. The services were next to each other. The two grounding electrode systems are required to be bonded together.

Yes 250.58. Thats what I was thinking.

Could a lightning protection system be bonded to the building GES? I'm looking but don't see it. Another NFPA publication perhaps?
 

Dennis Alwon

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I am confused here are you thinking the ground rod cannot be bonding to the other electrodes? The article just says 6' away-- help me out here.
 

cadpoint

Senior Member
Location
Durham, NC
They used to. Now we gotta do it for them (apparently it's too much work for them to drive their little weenie 1/2"x48" rods) and provide them with a way to latch onto our ground.

.1/2" only if "listed" for grounding electrode, and is 5/8" or 3/4" prevailing per material used.

250.52(A)(5)(a) & (b)... plus it helps to have the right mold to blast a cap to :)...

48" :confused:
 

480sparky

Senior Member
Location
Iowegia
.1/2" only if "listed" for grounding electrode, and is 5/8" or 3/4" prevailing per material used.

250.52(A)(5)(a) & (b)... plus it helps to have the right mold to blast a cap to :)...

48" :confused:


Tele and cable companys could care less about the NEC. Least 'round here. Split bolt onto our #4 bare, or stick a 48x? in the ground with a bug nut on it and beat feet.
 

cadpoint

Senior Member
Location
Durham, NC
Tele and cable companys could care less about the NEC. Least 'round here. Split bolt onto our #4 bare, or stick a 48x? in the ground with a bug nut on it and beat feet.

Sir:
You are Da Man to tell them otherwise! :grin:

Local, yes we support or supply their point of attachment @ a demark, it's not to supply an application like 48", Gezz... this is not carte blache around here...
 

don_resqcapt19

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Staff member
Location
Illinois
Occupation
retired electrician
Could a lightning protection system be bonded to the building GES? I'm looking but don't see it. Another NFPA publication perhaps?
It is required to be bonded to the electrical grounding system but must have its own electrodes. I think it is in NFPA 780.
 

M. D.

Senior Member
I'm not sure I understand the question,.. but that has never stopped me:smile:,..

250.60 Use of Air Terminals.

Air terminal conductors and driven pipes, rods, or plate electrodes used for grounding air terminals shall not be used in lieu of the grounding electrodes required by 250.50 for grounding wiring systems and equipment. This provision shall not prohibit the required bonding together of grounding electrodes of different systems.


800.93(D) Bonding of Electrodes.

A bonding jumper not smaller than 6 AWG copper or equivalent shall be connected between the communications grounding electrode and power grounding electrode system at the building or structure served where separate electrodes are used.....

So these and the two commonly driven to meet 250.56 must be spaced at least 6' from each other
 
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