Conduit in stairwells

[conmgt]

Hello,

It would be extremely convenient for me to horizontally pass through a stairwell in a commercial property to feed a subpanel on the other side of the stairwell.

Specifically, to get from a hallway inside the building on the interior side of the stairwell to a panel that would be mounted on the exterior of the stairwell wall. The conduit would be tight to the ceiling of a stair landing with no pull or junction boxes, just a horizontal run of 2".

Something tells me that this is frowned upon. I've only noticed conduit serving lighting in stairwells and piping serving sprinklers. Are there specific rules about stairwells and the forbidding of using them like a chase ?

 

[don_resqcapt19]

If that is a fire exit stair (exit enclosure), then the building codes do not permit any conduit or wiring not required for the stairs.

NFPA 101, the Life Safety Code, in 7.1.3.2.1(10) prohibits penetrations into an exit enclosure except as permitted in (a) though (i). Items (b) and (c) address electrical installations.
“(b) Electrical conduit serving the exit enclosure.
(c) Pathways for devices for security and communications systems serving the exit enclosure where pathways are installed in metal conduit”

The 2020 NEC will address this in a new section, 300.25 Exit Enclosures (Fire Stairs).
The text in the Second Revision reads.

300.25 Exit Enclosures (Stair Towers).
Where an exit enclosure is required to be separated from the building, only electrical wiring methods serving equipment permitted by the authority having jurisdiction in the exit enclosure shall be installed within the exit enclosure.

 

[conmgt]

Thank you.
It's pretty straight forward.

 

[kwired]

If that is a fire exit stair (exit enclosure), then the building codes do not permit any conduit or wiring not required for the stairs.

NFPA 101, the Life Safety Code, in 7.1.3.2.1(10) prohibits penetrations into an exit enclosure except as permitted in (a) though (i). Items (b) and (c) address electrical installations.
“(b) Electrical conduit serving the exit enclosure.
(c) Pathways for devices for security and communications systems serving the exit enclosure where pathways are installed in metal conduit”

The 2020 NEC will address this in a new section, 300.25 Exit Enclosures (Fire Stairs).
The text in the Second Revision reads.

Does that really need to be in NEC?

It is a requirement by other codes. An informational note somewhere referencing the other code may have been acceptable IMO.

If NEC were to reference every possibility of something triggered by other codes the hard copy would gain significant thickness.

All this really does is make this enforceable by the EI now.
The fire/life safety inspector is still going to reject it if the EI doesn't.

 

[don_resqcapt19]

Does that really need to be in NEC?

It is a requirement by other codes. An informational note somewhere referencing the other code may have been acceptable IMO.

If NEC were to reference every possibility of something triggered by other codes the hard copy would gain significant thickness.

All this really does is make this enforceable by the EI now.
The fire/life safety inspector is still going to reject it if the EI doesn't.

Like many things where the electrician has been ignoring other codes or installation rules they find their way into the code. The torque rule and the rule in 408.41 are rules that have long been part of the listing standard and long ignored by the installing electrician, so they were added to the actual code.
The substantiation for this new code rule said:

NFPA 101 (2018 edition), Section 7.1.3.2.1 (10) (b) prohibits installing conduits in a "separated exit enclosure" (stair tower) unless the conduits are "associated" with the exit enclosure. This type of prohibition belongs in the NEC® and not buried in the Life Safety Code, where electrical designers, inspectors, and installers are not aware of the prohibition.

 

[kwired]

Like many things where the electrician has been ignoring other codes or installation rules they find their way into the code. The torque rule and the rule in 408.41 are rules that have long been part of the listing standard and long ignored by the installing electrician, so they were added to the actual code.
The substantiation for this new code rule said:

NFPA 101 (2018 edition), Section 7.1.3.2.1 (10) (b) prohibits installing conduits in a "separated exit enclosure" (stair tower) unless the conduits are "associated" with the exit enclosure. This type of prohibition belongs in the NEC® and not buried in the Life Safety Code, where electrical designers, inspectors, and installers are not aware of the prohibition.

I still disagree that it belongs in the code main content, it does not really comply with what is mentioned in first sentence of 90.1(A).

It sort of infringes on what is mentioned in second sentence o 90.1(A), like many other things that have been put into the code over the years.

I would have less disagreement if they simply put in an informational note somewhere indicating you may want to check with NFPA 101 and/or specific portions of it. The designers mostly already know they need to comply with other codes, the installers often do as well.

Same goes for a lot of other issues out there where there is a hazard but not direct hazard that is covered by NFPA 70.

If I am working in a chapter 5 hazardous location, yes I need to comply with what it written in chapter 5 for what I install. But it doesn't tell me that it may be a bad idea to go into an existing C1D1 location with an abrasive type, spark producing cutter when performing my installation, maybe it should??

 

[FionaZuppa]

Does that really need to be in NEC?

It is a requirement by other codes. An informational note somewhere referencing the other code may have been acceptable IMO.

If NEC were to reference every possibility of something triggered by other codes the hard copy would gain significant thickness.

All this really does is make this enforceable by the EI now.
The fire/life safety inspector is still going to reject it if the EI doesn't.

NFPA does a terrible job of organizing authority and use of back references. If they dupe it into NEC and the authority source is then changed, then you're left with a mish-mosh of this & that. Best to just make the reference as you noted. Simple to just write "see NFPA code book 101" or whatever, etc. NFPA needs better management to understand how organizing related sets of data should be done.