What does your jurisdiction require for the support of fixtures in/on a grid ceiling?

2002 MASSACHUSETTS ELECTRICAL CODE (AMENDMENTS)

Most times we use 12 awg ceiling tie wire for this, supported by one attachment point, however job specs range greatly.

We have done jobs where the job spec was four separate wires from four separate points of attachment, and this was for a job with all 2' x 2' drop ins.

Also job specs may require attachment to the grid along with the independent supports.

Ryan, we are required to support our fixtures to the structure, I am being told that is due to our siesmic situation but can't get a code reference. Some inspectors are requiring all four corners. This is also writen into 90% of job specifications.

Roger

Roger,

You have a 'seismic situation' in NC?
I don't think I ever heard of any quakes down there.

Bill

Bill,
When's the last time you heard of VA having an earthquake? But we ARE a Seismic 1 area and therefore required to support to structure.

That does NOT supersede 410 requirements which says we have to support to grid as well. If you don't screw/clip to grid, you always push the light up when changing tubes, so we always required both.

Hello Bill, we actualy had one in Alabama that shook me out of bed (exageration ) not to long ago.
http://www.al.com/newsflash/regional/?stories/0429earthquake.html

Rare Southern quake near Georgia-Alabama
state line rattles several states; 4.5 magnitude


The Associated Press
4/29/03

ATLANTA (AP) -- A 4.5 magnitude earthquake centered in northern
Alabama rattled windows and bookshelves around the South early
Tuesday.

The rare Southern quake, which occurred at about 5 a.m., was centered
near the Alabama-Georgia line, 27 miles northwest of Rome, Ga.,
according to the U.S. Geological Survey's Web site.

The quake was felt as far away as North Carolina and Kentucky.
Emergency officials said they had not heard any reports of serious
damage.

In Atlanta, about 160 miles from the epicenter, the quake moved dishes
and pictures on shelves.

"My whole house shook, I could feel the whole wave go north to south,"
said Barry Goodno, a Georgia Tech structural engineering professor who
specializes in earthquakes. "Everything was rattling through the room. It
was not what I expected in Georgia.

"It's the kind of motion that could weaken structures or cause further
damage," Goodno said. "It's not something to be overlooked. This could be
a precursor, it could be a one-time release of energy, it could be an
indication of things to come for several weeks."

Carolyn Parker of Gadsden, Ala., says the earthquake lasted about 45
seconds and woke her up.

"At first I thought it was like thunder," she told WSB-TV. "Then it was a lot
heavier. It rattled the windows.

"My husband jumped out of bed. He said he thought it was like the end of
the world or something. He ran outside."

Nick Jebeles of Remlap, Ala., said he and his wife also were awakened.

"I went out on my back porch because I thought it was a tornado, but the
weather was fine," he said.

* * *

TS

Roger

[This message has been edited by Roger (edited 10-22-2003).]

Our inspectors (in Central Florida) only require 2x4 and 2x2 flourescent fixtures to be screwed off to the grid on at least opposite corners or in the middle, unless it is spec'd otherwise in the prints. Is there a specific code reference to cite? I guess I should get out the book and look for myself. In supporting fixtures by grid wire (if spec'd) or supporting fixture whips or feeds, we are allowed to use the same support brackets or hooks that the grid guys hang to tie their wires to. Some jurisdictions (mainly in the city) require the support wires we add to be identified by yellow or orange paint or even just tagged by a piece of colored tape so that it is readily able to be identified by them as such.

Gunther: I don't have my IBC here at the house, but if you are asking for a building code reference, try IBC 1621.2.5. If you are in a siesmic design catagory D1 or D2 or E, you will need to comply with the "CISCA 3-4" standard, as per the 2000 IBC.

I apologize for not having more for you, I will see what I can find tommorrow.

Gunther, the specific NEC article is 410.16(C).

It's interesting that there are no UL assemblies in rated grid ceilings (UL orange books)that require layin fixtures be supported to the structure.

Roger

ryan,
in caleeforneea it's chapter 25 of the building code and u.b.c.standard 25-2 that describes the installation proceedure.two #12 wires to each fixture at a minimun and they can have slack.any fixture that weighs over 56# must have approved hangers and be supported from above.if it is a listed system you would follow the installation instructions.

In addition to pwood's post.
The 2 wires, diagonal corners (in addition to the remaining 2 corners being secured to the grid) are a minimum.
This is one place where the CBC can be amended by a municipality, and many do.
Some jurisdictions require 4 corners to be wired, with 4 screws. Some want at least 2 wires, with all 4 corners secured to the grid (usually accomplished w/ tek screws).

I once had a job spec where the architect/engineer (from out of State) must not have been too sure of him/herself.
The plans showed 4 vertical support wires, and 4-45° splayed wires for each fixture!
Another T-Bar rule here is that the grid must be suspended at all 4 corners of the fixture...S

Bill
Westchester County, NY is considered a seismic 2 area. There is a chart in the Fire and Prevention code of NYS that shows the seismic designation for all areas of NY.

Pierre

Pierre,

Yes! I have heard that NY State experiences seismic events regularly. I assume they are not that noteworthy though or they would make the Headlines more.

I guess I forget sometimes, living on a Sand Bar.


Bill

Which code is amended in White Plains (Westchester) to require independant fixture support?