bus duct clearance

[Jay Pai]

I have 480V feeder/plug-in bus duct mounted up in steel.

The electrical inspector is stating that bus duct must maintain 42" clear from any steel (bottom chord of truss/bar joist and diagonals) as well as 6.5 ft headroom clearance...coming from Article 110.26

I know this is wrong, and I can install bus duct anywhere without having to worry about steel clearance but cant find verbiage in the code.

 

[bdarnell]

I wouldn't say that you can install busway ANYWHERE without worrying about clearances. If you installed your busway between two bar joists, which are typically 5 to 6 feet on center, then installed a bus plug, you would have a clearance issue, IMO.

Now, if it is feeder bus only, then that's another story. It should be able to be installed in the same fashion as a conduit feeder. It isn't likely to require examination or adjustment.

 

[Jay Pai]

I agree, I am going to tell the inspector/Owner that busway is considered an enclosed raceway...similar to conduit as stated in both Article 100 definition of raceway (an enclosed channel of metal designed for holding busbars) and busway Article 368 (busway is a grounded metal enclosure).