Supporting Fixtures

Status
Not open for further replies.
M

mstrlucky74

Senior Member
Location
NJ
Curious, as I have not come across this note before( All fixtures must be suspended/supported from all 4 corners from structure above). Forlay-in 2x2 or 2x4 I was under the impression the guys( in NYC) were just layingthese in and using clips and not attaching to structure above. Don’t think this is seismic related although I’mnot sure. Has anyone done this in NYC. Are you just using aircraft cable? Thanks.
 
It is a building spec (IBC) that is based on if the install is in a seismic zone.

It is usually just 2 supports on opposite corners diagonally. 4 corners may be a local rule or EE spec.

Most common material used is ceiling grid wire installed separate from the grid. The support wiring must be identifiable and spray paint is common. Pre paint the ends of a bundle or two and away you go.
 
jumper said:
It is a building spec (IBC) that is based on if the install is in a seismic zone.

It is usually just 2 supports on opposite corners diagonally. 4 corners may be a local rule or EE spec.

Most common material used is ceiling grid wire installed separate from the grid. The support wiring must be identifiable and spray paint is common. Pre paint the ends of a bundle or two and away you go.
Click to expand...


The support wires for the fixture don't have to be identifiable, nor do wires that support conduit if they are tied from the deck to the fixture, as they are not part of the ceiling grid system. Just saying.
 
Strathead said:
The support wires for the fixture don't have to be identifiable, nor do wires that support conduit if they are tied from the deck to the fixture, as they are not part of the ceiling grid system. Just saying.
Click to expand...
Somewhere in this forum I remember reading that if support wires are used they have to be "identified for intended use" and I remember learning this in a CEU class. I am also under the impression that the suspended ceiling has to have a specific rating in order for troffers to be merely screwed into the grid. I can't find any of this in the NEC but it may be part of a building code. Someone please correct me if I'm wrong.

410.36 Means of Support.
(B) Suspended Ceilings. Framing members of suspended ceiling
systems used to support luminaires shall be securely
fastened to each other and shall be securely attached to the
building structure at appropriate intervals. Luminaires shall be
securely fastened to the ceiling framing member by mechanical
means such as bolts, screws, or rivets. Listed clips identified for
use with the type of ceiling framing member(s) and luminaire(
s) shall also be permitted.
Click to expand...
 
Where mstlucky works they don't use support wires they use 1/4" pencil rod which is considered part of the building structure.
 
infinity said:
Where mstlucky works they don't use support wires they use 1/4" pencil rod which is considered part of the building structure.
Click to expand...
I can understand that in his case because he's working in NYC on a specific job where they're calling for this. NYC has many specific requirements like this. If he's using threaded rod to support the troffer and the suspended ceiling is using a method other than threaded, rod I don't see any reason to specifically identify it for the intended use.

I came across this Mike Holt article in EC&M Magazine - kind of supports what I was saying:

http://www.ecmweb.com/nec/code-qa-41
 
Supporting Fixtures

Strathead said:
The support wires for the fixture don't have to be identifiable, nor do wires that support conduit if they are tied from the deck to the fixture, as they are not part of the ceiling grid system. Just saying.
Click to expand...

If it’s within a fire-rated assembly they do.

300.11(A)(1)

I recently had an inspector in Florida require this in a ceiling that wasn’t fire rated; came in with this BS at the final. Tried to argue, got the “my town, my rules” response. It was one of those things where I just had to suck it up to get the heck out of there so they could get a CO. He let us mark them with tape and go.

Sent from my iPhone using Tapatalk
 
brantmacga said:
If it’s within a fire-rated assembly they do.

300.11(A)(1)

I recently had an inspector in Florida require this in a ceiling that wasn’t fire rated; came in with this BS at the final. Tried to argue, got the “my town, my rules” response. It was one of those things where I just had to suck it up to get the heck out of there so they could get a CO. He let us mark them with tape and go.

Sent from my iPhone using Tapatalk
Click to expand...

That section is not for light fixtures it is part of article 300 wiring methods, and the applicable items requiring marked wires are, raceways, cable assemblies, boxes, cabinets, and fittings. And to put it in a common sense perspective. All of the above, the wire is attached to the structure and to the ceiling grid. In order for an inspector or other to easily distinguish that the wire is, in fact, not part of the ceiling grid support system at a glance they are identified. The wires we are referring to for the fixture are NOT ceiling support wires and they are easily identified as such because they go to the fixture not to the grid.
 
It's not just for seismic, fire departments don't like the fixtures falling on their heads when they are poking at the suspended ceiling during a fire.
 
Status
Not open for further replies.
Top