Steel structure grounding

[bbvolt]

To some it may be a simple question but,
Question came up on a new type of steel building ,
It is called Cover all . Basic 3 1/2 in steel tubing galvanized, anchored in concrete footers
with a tarp like outer material for a skin. The
building is 200 foot long by 80 foot wide by 38 foot at peak. This building is to have 10 400 watt M Halide high bays for light and other small items ex.
fans etc. How do you ground this building steel properly. There will be a 60 amp sub panel attached to the interior for power. All help welcome.

 

[George Stolz]

Re: Steel structure grounding

By 250.32, you have two options for grounding the subpanel with the feeders supplying it. I would run a grounding conductor with your feeders, and then connect the building steel to the grounding bar in your subpanel.

Hope that helps...

 

[bbvolt]

Re: Steel structure grounding

George would there be any positive source for using ground rods driven at the four corners of the building and bonding the steel. In addition to the panel ground bonded to the steel.

 

[George Stolz]

Re: Steel structure grounding

It's not required, but can't hurt.

Is this being required of you?

 

[bbvolt]

Re: Steel structure grounding

Is there any theory about two different ground rods
driven for the same original service disregarding how many sub panels. Ground rods driven at hundreds of feet apart. Meaning different resistive values
from the ground rods. Which path is is taken at a fault.

 

[petersonra]

Re: Steel structure grounding

Originally posted by bbvolt:
Is there any theory about two different ground rods
driven for the same original service disregarding how many sub panels. Ground rods driven at hundreds of feet apart. Meaning different resistive values
from the ground rods. Which path is is taken at a fault.

The grounding electrode is not part of the fault clearing path unless you have made a serious error in the way you hooked it up.

You can have as many grounding electrodes as you want connected in parallel, as far away from each other as you want, as long as you abide by the wire size requirements for connecting them together.