grounding substation Bollards

[tbyrne64]

Does anyone know if bollards in a eletric utility substation must be grounded. The Bollards are 4 inch diameter steel pipes filled with concrete, which are used as a protective barriers for equipment. There is an extensive ground grid in the sub to which the bollards are not currently connected. I'm reviewing IEEE-80 for clarification. Any ideas?

 

[dpc]

I would say they need to be bonded to the ground grid, just like any other piece of steel structure.

 

[jghrist]

I wouldn't bother. They are not likely to get energized and still be in a position that someone could touch them without touching whatever is energizing them.

 

[dpc]

During a fault, there could be a potential difference between the earth where the bollard is installed and the grounded equipment that could be nearby.

 

[waross]

I would consider then equivalent to metal fence posts. Ground them. I was on a 25MVA sub last summer. The plans called for bollards and called for them to be grounded. I can not think of a piece of metal inside the substation fence that was not grounded.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[gepman]

I ground the bollards on all my MV equipment including bollards for oil filled padmount transformers, MV switchgear, etc. at industrial sites.

If this is a true electric utility substation everything inside the fence including the fence is grounded at least for the specifications of the two utilities for which I have done work.

 

[davidbeach]

Not only ground, but visibly grounded. Upon first entering the substation one is to check to make sure that all grounds are present and accounted for; missing grounds to be reported immediately. Crews wouldn't work around an ungrounded bollard.