Suspeneded Linear Lighting systems are mounted to T-Bar ceilings on the grid. Aircraft cable is the most common method used to support fixture. The issue is the method of supplying power to the lighting system. The most common method is a SVT or SJT white cord that is strapped to the aircraft cable. A j-box is mounted to a caddy clip above the ceiling and and the cord is passed through a 3" canopy, through a metal flex connector into the juction box. The mount is either ETL or UL listed as part of the system. Inspectors have an issue since the mount is in the gray area between NEC and UL standards. NEC does not want a SVT in the ceiling and the fitting is considered a raceway which cannot have a SVT cord inside. Hundred's of thousands of power mounts are installed each year. How can I get a clear approval and maybe a exception clause added in the future?
SVT Cord/T-Bar for Suspended Fixtures
- Thread starter pnkuehnel
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pierre
Senior Member
- Location
- Westchester County, New York
Re: SVT Cord/T-Bar for Suspended Fixtures
Cords are required by UL to be visible for their entire length. That is part of the reason it is not permitted to be installed above the portion of a suspended ceiling that is not visible when the ceiling tiles are in place.
Just about every code cycle there is a proposal to have this changed and every time that type of proposal is declined.
Your answer lies in coming up with a wiring method that will comply, and make it a standard for your company to follow.
Cords are required by UL to be visible for their entire length. That is part of the reason it is not permitted to be installed above the portion of a suspended ceiling that is not visible when the ceiling tiles are in place.
Just about every code cycle there is a proposal to have this changed and every time that type of proposal is declined.
Your answer lies in coming up with a wiring method that will comply, and make it a standard for your company to follow.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: SVT Cord/T-Bar for Suspended Fixtures
maybe a exception clause added in the future?
Deadline for the 2008 NEC proposals has passed.
Why can you use a T-Bar hanger and install a j-box with its front flush with the ceiling tile?
If its not strong enough, then a similar method should work. If hundreds of thousands are being installed then an acceptable method would have a ready market.
maybe a exception clause added in the future?
Deadline for the 2008 NEC proposals has passed.
Why can you use a T-Bar hanger and install a j-box with its front flush with the ceiling tile?
If its not strong enough, then a similar method should work. If hundreds of thousands are being installed then an acceptable method would have a ready market.
Re: SVT Cord/T-Bar for Suspended Fixtures
The SVT cord only passes thru a 1/2" long aperture and is fully accessible inside the j-box. You do need to remove a ceiling tile to access the j-box however. Architects expect to see the smallest possible ceiling canopy with no hardware exposed. What is the rationale for a cord not to be in a raceway or conduit? Is it overheating or non visible damage to cord?
The design used mostly is an industry de facto standard. There are design approaches that provide a cord shield, the shield is removed with the J-Box cover, however the SVT cord is still in the ceiling. Do the wiring connections need to be accessible from below the ceiling?
If a mounting system is integral to a luminaire design and is listed in a UL or ETL listing, how does the NEC code apply?
The SVT cord only passes thru a 1/2" long aperture and is fully accessible inside the j-box. You do need to remove a ceiling tile to access the j-box however. Architects expect to see the smallest possible ceiling canopy with no hardware exposed. What is the rationale for a cord not to be in a raceway or conduit? Is it overheating or non visible damage to cord?
The design used mostly is an industry de facto standard. There are design approaches that provide a cord shield, the shield is removed with the J-Box cover, however the SVT cord is still in the ceiling. Do the wiring connections need to be accessible from below the ceiling?
If a mounting system is integral to a luminaire design and is listed in a UL or ETL listing, how does the NEC code apply?
Re: SVT Cord/T-Bar for Suspended Fixtures
Go to this page and look at the canopies, they are made to mount to a flush box, why can't your product do the same?
Otherwise, a modular plug could be designed so that the wiring above the ceiling could NEC compliant to a small addapter at the ceiling surface and the white cord attached here.
Roger
Go to this page and look at the canopies, they are made to mount to a flush box, why can't your product do the same?
Otherwise, a modular plug could be designed so that the wiring above the ceiling could NEC compliant to a small addapter at the ceiling surface and the white cord attached here.
Roger
Re: SVT Cord/T-Bar for Suspended Fixtures
if this post is related to the thread i was seeing over this weekend, the mfg drawings were sourly lacking.
in the past i have asked the inspector to meet me, either on the site, or in his office, to help me work out a solution.
in my experience, an inspector will not design your work, but if you are prepared with several options, he/she will tell you which ones are acceptable.
if this post is related to the thread i was seeing over this weekend, the mfg drawings were sourly lacking.
in the past i have asked the inspector to meet me, either on the site, or in his office, to help me work out a solution.
in my experience, an inspector will not design your work, but if you are prepared with several options, he/she will tell you which ones are acceptable.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- Semi-retired engineer
Re: SVT Cord/T-Bar for Suspended Fixtures
I don't really understand the reason for this code requirement. It is akin to not being able to run NM in conduit (which I think was changed in the 2005 edition). There is no real good reason for it, but it is a requirement, so you have to abide by it.
[ November 28, 2005, 05:24 PM: Message edited by: petersonra ]
I don't really understand the reason for this code requirement. It is akin to not being able to run NM in conduit (which I think was changed in the 2005 edition). There is no real good reason for it, but it is a requirement, so you have to abide by it.
[ November 28, 2005, 05:24 PM: Message edited by: petersonra ]
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