Can I bond/ground to the structure of a steel building?

[Farman]

Still quite new at this stuff, and I'm trying to clarify a grounding idea. In my fiddling with small 12v solar setups, I continue to think along the lines of automotive circuitry, except that I've always floated the negative polarity back to the batteries. Hope I said that right.

So if I have a little 12v system being used in a pre-engineered steel building, could I use the building just like a car's chassis?

If I'm understanding the concept correctly, I wouldn't have to use twice the amount of wire.

[SunEagle]

Still quite new at this stuff, and I'm trying to clarify a grounding idea. In my fiddling with small 12v solar setups, I continue to think along the lines of automotive circuitry, except that I've always floated the negative polarity back to the batteries. Hope I said that right.

So if I have a little 12v system being used in a pre-engineered steel building, could I use the building just like a car's chassis?

If I'm understanding the concept correctly, I wouldn't have to use twice the amount of wire.

The problem with using your building for a ground instead of some type of ground rod can result in electric shock should someone be touching the building metal and standing on the earth during a fault. It is always better to have a path for the fault to ground to go though using wire and steel instead of a human.

[Farman]

I should have mentioned that the building is attached to ground rods that are driven into the earth. Does that change the safety issue you bring up?

[Ampster]

I should have mentioned that the building is attached to ground rods that are driven into the earth. Does that change the safety issue you bring up?

I would refer to NEC for starters. How far is the nearest ground rod?

[Farman]

How far is the nearest ground rod?

From what?

The ground rods are within a foot or two of the building's foundation wall. The nearest rod to the battery bank would be about 15 feet or so.

[Mike90250]

I would NOT use the building ground as a minus return . You have screwed joints, paint, weatherstrip and the inherent higher resistance of steel over that of copper.

Plus the safety factor.

[SunEagle]

I should have mentioned that the building is attached to ground rods that are driven into the earth. Does that change the safety issue you bring up?

I would run a ground wire from the solar system to one of those building ground rods. It would be safer to have a direct path to ground then to go through the components of a metal shed.

[Farman]

Case closed.

Thanks for the input, it really does help.