markjkubicki
Member
- Location
- New York City
as Architectural Lighting Consultants, we often mount lighting fixtures in "difficult" locations (ex: on the metal mullions of the curtain wall); and to access power to them, the EE often routes conductors through the mullions. However, there seems to be a consistent inconsistency on what is an allowable method:
a) the fully enclosed metal mullion system (usually an aluminum extrusion with a snap-cap) is an acceptable raceway, and insulated conductors (THHN or equivalent) can be pulled thru it without issue provided the mullion system is properly bonded to ground).
b) the mullion system is not an acceptable raceway, and the cable must be enclosed within its own raceway (EMT, FMT, <etc.> )
c) the mullion system is not an acceptable raceway, and the cable must be enclosed within a RIDGID conduit (FMT is NOT acceptable) regardless of the length of the run; this is particularly problematic in that the often necessary flexibility to route thru bends... is not possible
d) power CANNOT be run thru architectural mullions (period)
Your thoughts would be greatly appreciated in advance,
Mark Kubicki - Tillotson Design
a) the fully enclosed metal mullion system (usually an aluminum extrusion with a snap-cap) is an acceptable raceway, and insulated conductors (THHN or equivalent) can be pulled thru it without issue provided the mullion system is properly bonded to ground).
b) the mullion system is not an acceptable raceway, and the cable must be enclosed within its own raceway (EMT, FMT, <etc.> )
c) the mullion system is not an acceptable raceway, and the cable must be enclosed within a RIDGID conduit (FMT is NOT acceptable) regardless of the length of the run; this is particularly problematic in that the often necessary flexibility to route thru bends... is not possible
d) power CANNOT be run thru architectural mullions (period)
Your thoughts would be greatly appreciated in advance,
Mark Kubicki - Tillotson Design