Steel Column Grounding

[mull982]

Hello

I have an "A-Frame" (Steel Columns form an A shape, to support a sloped room) covered building at a cement plant where I work. Each end of the steel columns in set in the ground with a concrete footer. They are currently changing out a number of these columns a footers for elevation issues with new construction. Prior to construction some of the columns had a ground wire welded to the steel columns. As the contractor replaced a number of columns they did not reattach the ground wires and now need to go back and do so. Does anybody know what the code calls for in this situation as far as grounding the steel columns. Does every steel column have to be grounded, or just a certatin number? (Remember that a set of columns on each side of the building are connected because of the "A" shape support structure.

Thanks

Mull982

 

[petersonra]

Is there any requirement that they be grounded at all?

 

[steve66]

Does the building have a lighting protection system?

STeve

 

[iwire]

The NEC does not require grounding / bonding each steel column.

However it is a common specification in many of the buildings we do from scratch that we install a ground ring and bond each column to the ring.

 

[jtester]

If the columns are likely to become energized, you might look at 250.104(C) which would require them to be bonded unless intentionally grounded. That might be the source of the original grounding/bonding connections.

Jim T