I have a question about grounding. The scenario is my shop has a concrete floor with metal framing and siding. The panel is mounted to the wall via struts. A #2 Al ground wire is ran from the meter to the panel. I don't believe they ran a separate ground rod for the panel. I already have a ground rod right outside the building where we had some lightning rods installed. Am i going to hurt anything by running a ground wire from the panel grounding bar to the ground rod? It's going to cost me a few dollars for 6' of copper wire to do it and next to zero effort.

The building is concrete slab with rebar but no way to access it now. They installed metal weld plates into the wet concrete and welded the upright posts to them.

Grounding rods are fairly inexpensive. I think I will tie into the one for the lightning rods, tie the grounding lug inside the Panel to structural steel and bury one more rod in an open trench in digging today to lay line out to a sub panel

Thank you for your help

  • How was the shop foundation constructed, and is there a way to tie into its rebar? Commented Sep 1, 2017 at 11:40

2 Answers 2


Here's a diagram covering the grounding possibilities. There are new clarifications about lighting protection and grounding in the NEC 2017 code. By the way NEC 2017 becomes law in this state today.

enter image description here

Hope this helps. Good luck.



The more interconnects in your grounding electrode system, the merrier. Dirt is not a particularly good conductor, so the more stuff you can tie, only strengthens the capacity of the electrode to keep you safe. Tie into the reinforcing rod and metal frame if you can.

Aluminum ground wires are not a good idea outdoors, though. They are prone to corrosion especially where they meet copper.

  • It doesn't seem like he has any ground rod at the structure other than the one for the strike terminator, though... Commented Sep 1, 2017 at 11:39
  • May be a ufer but should be tied to panel even if mounted on building steel. I would add as Harper suggests , lots of grounding close to your panel is a good thing.
    – Ed Beal
    Commented Sep 1, 2017 at 12:21

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