Ground rod for sidewalk sheds

[geokanda]

I have a question on bonding of sidewalk sheds the local authority is asking us (the electrical contractor) to drive ground rods for every section of sidewalk shed. I believe if we drive ground rods for every section this would be a secondary grouding system for existing electrical system where the power is comming from for the lighting of these sidewalk sheds.

any comments please feel free

 

[infinity]

What kind of sidewalk sheds are you referring to?

 

[augie47]

250.54 allows for auxiliary grounding electrodes

 

[nhfire77]

What the heck is a sidewalk shed?

 

[benaround]

It is a seperate structure !

 

[tom baker]

Does this shed have electrical circuits?

 

[Nium]

sidewalk shed

sidewalk shed

I'd guess geokanda you're from New York City because googling the term sidewalk shed returned...

sidewalk shed -- a structure built over the sidewalk and around the exterior of a building, while work is occurring on the building, to protect pedestrians from falling debris; also called a ?sidewalk bridge?

..with lots of pictures and references to the Big Apple.

Please, if you would, explain in more detail what the inspector is wanting of you and verify that the above is the correct definition of a "sidewalk shed".

 

[geokanda]

each section of independent scaffolding is freestanding the inspector wants a ground rod for each section. There is lighting circuits in conduit going back to the buildings service for lighting. The conduit is ridgid gal and mechanically connected. I feel that with the additional ground rods installed the building service has a secondary means of grounding. Do you agree or disagree.

 

[suemarkp]

What type of power is going to each sidewalk shed -- feeder or branch circuit? Driving a ground rod seems stupid for a temporary structure. Bonding the metal sections could be prudent though.

If the sheds are not really connected to the main building, then they seem like separate structures to me. Separate structures are grounded independently of other structures. I could see him requiring you to have 2 rods at each shed if fed by a feeder unless you can show the rods are 25 ohms or less. However, bondind a rod to a rod at an adjacent shed or to the building grounding system may eliminate the second rod (but you'd need #6 or larger copper wire).

 

[Nium]

Seems to depend on how a sidewalk shed is interpreted. If the inspector is calling it a structure then you may want to ask the inspector if 250.32(A) Exception not requiring a grounding electrode "...where only a single branch circuit, including a multiwire branch circuit supplies the building or structure and the branch circuit includes an equipment grounding conductor for grounding the normally non-current carrying metal parts of equipment." would be applicable to your situation or not.