Ground Rod/conductor Size for Site Lighting

[metallica5]

Drawing detail for site lighting calls for 10' x 3/4" ground rods at concrete bases for parking lot lighting and bollard style walkway lighting for new retail building construction project. Detail also shows #8 bare copper bonding metal pole to ground rod. I assume engineer called for this to limit potential lightning damage. Crew installed 8' x 5/8" ground rods into poured bases by mistake. We do have equipment grounding conductors pulled in with circuit conductors. My question is: Will 8' ground rods with #8 copper be sufficient for intent or do we need to go back and install 10' x 3/4" with # 8 copper. I question the size of the #8 grounding conductor also. Thanks for feed back.

 

[rcwilson]

In my opinion, the concrete encased 8' rod is a much better ground than a single 10' rod. But my opnion doesn't count.

If the engineer/owner/inspector doesn't accept the installtion, try doing a ground resistance test comparing a single 10' rod and the foundation. Isolate the EGC so the test is reading just the one foundation/rod.

 

[jumper]

While specs should be followed and you may be dinged for that, the rods are just extra and not required by the NEC.

You pulled an EGC right?

Why do you question the #8?

 

[metallica5]

Yes, equipment grounding conductors were pulled in with circuit conductors separately. I questioned the #8 conductor as being underrated for capacity to the 10' rod but fine for the 8' rod?

 

[stickboy1375]

Why don't they just spec more concrete if someone is so worried about it? What on earth (pun intended) does a rod do differently then the concrete form?