Down Conductors To Ground Rod Question

[ThePunisher]

Our design presently shows that the building steel columns are used as ground conductors (criteria for down conductor requrement are met). Therefore, the aerial rods are bonded to the vertical steel columns. However, on grade, the steel columns are directly bonded to the unmderground grounding grid (plant electrical ground grid).

As far as I remember, we used to drive dedicated ground rods to each down conductors. In our case, I could have expected the steel column frame at grade connected to its dedicated ground rod and from this ground rod it will be bonded to the plant electrical grid. Is my concept correct? We used BS 6651 long time ago with that installation.

 

[ThePunisher]

Further to my question, can the underground ground rods which are directly connected to the lightning down conductors be interconnected to from a ring grid and be used as the Electrical Ground Grid for the building itself?

Appreciate your comments

 

[alehman]

I'm not sure I understand your first question. The answer to the 2nd question in the U.S. would be yes. Not sure about Canada, or wherever you are.

Alan
“The engineer's first problem in any design situation is to discover what the problem really is.” Unk.

 

[ThePunisher]

On the first question:

The down conductors are bonded directly to the electrical grounding grid that encircles the building. Is this allowed?

Is it going to be an acceptable installation if the down conductors are connected first to their associated ground rods and then these rods will each be bonded to the overall electrical ground grid?

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The answer to the 2nd question you mentioned, did you meant my 2nd separately posted question: "Further to my question, can the underground ground rods which are directly connected to the lightning down conductors be interconnected to from a ring grid and be used as the Electrical Ground Grid for the building itself?"