fire pump feeder protection

[lpalmer]

I have a request to change the designed MI cable fire pump feeders, which run from the service (with overcurrent protection) through the building to the fire pump controller/room, to RHH conductors installed in EMT. The cut sheet shows the RHH with conduit as a UL Classified two-hour rated cable when used in conduit. Has anyone run across this and does this meet the requirement of NEC 695-6 (b)?

 

[steve66]

This is the first I have heard of these. Hopefully, someone who has used these before will chime in. But until then, this might help:

www.vitalinkcable.com/pdf/ULFAQs.pdf

www.ul.com/regulators/janfeb2003.pdf

It looks like not just any RHH cable will work; it has to be listed as part of the fire rated assembly. Also, it looks like you have to support the cable in vertical runs of conduit.

Since you have OCP, I assume you have a disconnect. I think that disconnect has to be "supervised". Notice if these were service conductors, they still are not considered "outside" the building.

 

[bdarnell]

The listed electrical circuit protective systems specified in are typically constructed of fire resistant materials encasing the wiring system and supports, or cables on their own, such that the construction of the cable jacket and insulation provide the fire resistance.

I'm of the opinion that you cannot just install RHH conductors in EMT and get the electrical circuit protective system rating. It has to be a listed system. The only one I know of (there may be others) is Draka (www.drakausa.com).

Steve is correct. You do need to supervise the disconnect that is installed.