Grounding an architectural spire

[czylstra]

We are currently working on a project where the electrical inspector is requiring us to ground a metal spire, (an architectural metal spike that extends about 5' from the top of the building). This spike is bonded to the structural steel in the tower where it is located, but the structural steel in the tower is not bonded to the steel in the remainder of the building. Our first inclination was to bond the structural steel of the tower to the structural steel of the remainder of the building by means of a grounding conductor. Has anyone come across this before or have any suggestions?

 

[bphgravity]

I'm not certain the inspector can require anything in this circumstance. Unless the steel components meet the criteria to be used as a grounding electrode or the steel is exposed and likely to be energized, it is out of the scope of the NEC. In the event the building is legally required to have a lighting protection system installed as determine by your state building code or statutes, the inspector can not enforce the NFPA 780 or require any additional electrical installations not required by the NEC, even though the spire is likely to function as a lightning strike termination device (air terminal).

Bonding of the structure to the rest of the structural would certainly be advisable.

 

[infinity]

I think that Bryan's advice in the last sentence of his post is apt. I agree that this is probably outside the scope of the NEC. I would ask for a code reference from the inspector to see if this falls under another building or local code.

 

[tom baker]

Since its unlikely the sire could become energized, there is no requirement to bond it. If the concern is for lightning, unless the spire and building grounding is done per NFPA, it may not be acceptable from an insurance standpoint and make a lighting stike cause more damage.