Legally Required (smoke control) panel feeder - route through 2-hour rated stairwell?

[snik96]

I'm working on a high-rise building with pressurization fans / elevator control room on the rooftop. These are fed from a panel that's also on the rooftop, that is part of the Legally Required distribution system.

There is not a dedicated shaft available to route the panel feeder through vertically from the first floor, and maintain code-required 2-hour rating for smoke control.

I've heard of pressurization fan branch circuits being routed through fire-rated stairwells to maintain 2-hour rating. My question is, can the same be done for a panel feeder? If I run the conduit for the panel on the roof vertically through a 2-hour rated stairwell, is that an acceptable solution for the smoke control feeder?

 

[don_resqcapt19]

That may be an issue with 300.25.

 

[snik96]

Yeah, after some further discussion in the office, I think the consensus is the problem being the panel also services the elevator, which is a foreign system to the stairwell. If the panel were just servicing stairwell fans, then routing the panel feeder in the stairwell would be acceptable.

Not 100% sure that's correct, but seems likely.

 

[gadfly56]

If you use something like MI or VitaLink, which are inherently 2-hour, you wouldn't need a rated chase.