Help with Grounding Question Please...

[danielmarksbrewery]

I work in a large data center in the Midwest. We are in the middle of a large scale upgrade to an existing building. I noticed the electrical contractor using insulated strut straps to support 4/0 bare ground conductors that are connected to a grounding bus on the structural steel. The strut straps are connected to a piece of strut that is electrically isolated from any grounding source because they used insulated strut straps (caddy straps). The piece of strut is used to space the bare copper conductors apart from each other and isn't connected to anything, thus making it an ungrounded piece of strut. Is this a code violation? And if so where could I find the code reference that deals with this kind of a situation.

Thank you much!

-Daniel

 

[Dennis Alwon]

Maybe I am not following but isn't the structural steel connected to the struts? Is there an engineer for the job. This may be speced by the engineer because of it being a data center. Not exactly sure why it is done that way

 

[infinity]

Is this isolated strut likely to become energized? IMO it is not. Also the insulated straps will keep the strap/strut from causing the choke effect.

 

[danielmarksbrewery]

Thanks for the replies. The strut is not connected to the structural steel. It is not likely to become energized. I have heard of the choke effect but don't understand it very well. I did ask an engineer here and he wasn't sure why they did it that way either, but mentioned the same thing about the choke effect. Still seems strange to me that they haven't been consistent using insulated strut straps for support in places and then used regular strut straps in other places.