[Grabsumbuds8683]

For any guys in the retrofit buisness curious how the new article in 2014 code has been interpreted .... Does this apply to LEDs for gas station canopies under the metal roofing?




(F) Luminaires Installed in or Under Roof Decking. Luminaries installed in exposed or concealed locations under metal-corrugated sheet roof decking shall be installed and supported so there is not less than 38 mm (11?2 in.) measured
from the lowest surface of the roof decking to the top of the luminaire.

 

[HARRY304E]

For any guys in the retrofit buisness curious how the new article in 2014 code has been interpreted .... Does this apply to LEDs for gas station canopies under the metal roofing?




(F) Luminaires Installed in or Under Roof Decking. Luminaries installed in exposed or concealed locations under metal-corrugated sheet roof decking shall be installed and supported so there is not less than 38 mm (11?2 in.) measured
from the lowest surface of the roof decking to the top of the luminaire.

..............

 

[Grabsumbuds8683]

Stumped everyone?

 

[hardworkingstiff]

Stumped everyone?

I am since I can't find 410.10(F) in my 2011 NEC.

 

[kbsparky]

LEDs installed under roof canopies may not be the same thing as under corrugated metal roofing.

Those roof canopies usually have some sort of separation between the top of the roof, and the bottom of the ceiling -- which contain the "joists" of the structure.

OTOH, if there is no other structure and the "roof" and "ceiling" are the same layer of sheet metal, then the 1½" spacing must be maintained... such as would be found in an industrial building with bar-joists with corrugated metal roofing on top.

This section of the Code requires the same spacing for fixtures as conduits installed under such roofs.

 

[Grabsumbuds8683]

I am since I can't find 410.10(F) in my 2011 NEC.

lol 2014

 

[hardworkingstiff]

For any guys in the retrofit buisness curious how the new article in 2014 code has been interpreted .... Does this apply to LEDs for gas station canopies under the metal roofing?




(F) Luminaires Installed in or Under Roof Decking. Luminaries installed in exposed or concealed locations under metal-corrugated sheet roof decking shall be installed and supported so there is not less than 38 mm (11?2 in.) measured
from the lowest surface of the roof decking to the top of the luminaire.

If you are talking about the canopy decking itself, I would say no.

It appears to me this is intended to address fixtures installed under a deck that has material above the deck (concern for screws from the screws holding down the material above the deck). A gas station canopy does not have that (typically).

 

[Dennis Alwon]

The idea here is to keep a distance off the metal deck because it gets very hot. Similar rule applies to raceways under the deck as well as on top of the roof.

 

[hardworkingstiff]

The idea here is to keep a distance off the metal deck because it gets very hot. Similar rule applies to raceways under the deck as well as on top of the roof.

Dennis, looking at the information below, I disagree. It appears to me that the reasoning was purely physical damage and had nothing to do with heat.

Submitter: James H. Maxfield, City of Dover Fire & Rescue
Recommendation: Proposal to read:
410.10(F) Luminaires Installed in or Under Roof Decking
Luminaires installed in expose or concealed locations under metal -
corrugated sheet roof decking, shall be installed and supported so there is not
less than 38 mm (1 1/2 in.) measured from the lowest surface of the roof
decking to the top of the luminaire.
Informational Note: Roof decking material is often repaired or replace after
the initial roofing installation and may be penetrated by the screws or other
mechanical devices designed to provide “hold down strength of the waterproof
membrane or roof insulating material.
Substantiation: Physical damage is not limited to only cables, raceways and
boxes installed within this area. The luminaire itself, conductors and its
associated equipment such as the ballast(s) and transformer within the
equipment are also subject to teh same physical damage. Section 300.4(D) of
the NEC does not permit the cables, raceways and boxes to be installed within
this area therefore the addition of this new section would also prevent the same
damage to the luminare. Panel 3 currently recognizes the physical damage and
potential hazard to the electrical installation within this area and Panel 18
should also recognize the same potential hazards.
Note: Supporting material is available for review at NFPA Headquarters.
Panel Meeting Action: Accept in Part
The rejected part is the informational note.
Panel Statement: The informational note is already covered in 300.4(E).
Number Eligible to Vote: 11
Ballot Results: Affirmative: 11

 

[Dennis Alwon]

Dennis, looking at the information below, I disagree. It appears to me that the reasoning was purely physical damage and had nothing to do with heat.

I agree--it is for the screws -- I knew that but forgot it.....That's what happens when I think

 

[Semi-Ret Electrician]

On a log cabin I once had 1/2" RMC penetrated by 12" long screws being used by insulators.

1 1/2" is a step in the right direction.

What about folks installing OSB siding with 2" nails, which land all around our Romex, when they miss!