Ground ring or ground rod electrode system

[hhsting]

I have a question in regards to the following:

I have cell tower and I have four ground rods 25 feet apart connected by copper conductor not smaller than #2 Awg forming grounding electrode system. The conductors and ground rods from top view is encircling forming ring shape as shown attached figure. Not sure is this ring or rod.

So to size the GEC from service disconnect should I use 250.66(A) connections to ground rods or 250.66(C) connections to ground ring?

Sent from my SM-G935U using Tapatalk

 

[Dennis Alwon]

If this ring meets the definition of a ring then I would use number 2 and have the benefit of both.

(4) Ground Ring. A ground ring encircling the building or
structure, in direct contact with the earth, consisting of at least
6.0 m (20 ft) of bare copper conductor not smaller than
2 AWG.

(F) Ground Ring. The ground ring shall be installed not less
than 750 mm (30 in.) below the surface of the earth.

 

[tom baker]

The ground ring at the cell tower I designed ended up being 3/0 as that is what the tower contractor used and had cadweld for. And this was with a 10'x10' x 4' thick foundation
Tower grounding is more elaborate than the NEC requires and its more for lightning protection.

 

[ceb58]

I have a question in regards to the following:

I have cell tower and I have four ground rods 25 feet apart connected by copper conductor not smaller than #2 Awg forming grounding electrode system. The conductors and ground rods from top view is encircling forming ring shape as shown attached figure. Not sure is this ring or rod.

So to size the GEC from service disconnect should I use 250.66(A) connections to ground rods or 250.66(C) connections to ground ring?

Sent from my SM-G935U using Tapatalk

The ground ring at the cell tower I designed ended up being 3/0 as that is what the tower contractor used and had cadweld for. And this was with a 10'x10' x 4' thick foundation
Tower grounding is more elaborate than the NEC requires and its more for lightning protection.

From your drawing you would also go to each tower leg, any fencing around the site and then to the building to be connected to the grounding bars.