My Question is whether there is a reference in the code on how to establish a raceway btwn floors . I have been told to use 1" EMT conduit as a sleeve. In addition use bushings make the conduits extend 2' below and above the penetration.
It would be here, but not as 2', unless this is some local code? And exposed... but it doesn't sound as if it will be inside the units???
334.15 Exposed Work.
In exposed work, except as provided in 300.11(A), the cable shall be installed as specified in 334.15(A) through (C).
(B) Protection from Physical Damage. The cable shall be protected from physical damage where necessary by conduit, electrical metallic tubing, Schedule 80 PVC rigid nonmetallic conduit, pipe, guard strips, listed surface metal or nonmetallic raceway, or other means. Where passing through a floor, the cable shall be enclosed in rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC rigid nonmetallic conduit, listed surface metal or nonmetallic raceway, or other metal pipe extending at least 150 mm (6 in.) above the floor.
But 2' above and below??? Why not just make it conduit the whole way? Also 250.86 exception 2 allows it not to be grounded, depending on what "short" is defined as by the AHJ. 4'+ isn't exactly 'short' IMO.
Exception No. 2: Short sections of metal enclosures or raceways used to provide support or protection of cable assemblies from physical damage shall not be required to be grounded.