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#77822 07/14/01 08:50 PM
Joined: Oct 2000
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Do light fixtures have to be supported by Ceiling Tie Wire?


I have a restaurant in La Mirada Calif. ( Concerned )


Thanks
Joe Rodriguez


Bill
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Joined: Mar 2001
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Special clips are made to fasten the fixture to the t-bar ceiling grid. Bolts screws, rivets or other mechanical fastening is also O.K. The t-bar is supposed to be securely fastened to each other and to the building at appropriate intervals. No mention of attachment to support wires. See Art. 410-16(c).

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Redsy,

Thanks, I was thinking there might be more strict localized codes for known Earthquake areas.

Any Californians out there?

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Bill


Bill
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I hear my name being called [Linked Image]

Here's the typicals in So. California - along with specifics for LA County [where La Mirada is]:

  • Troffers in T-Bar ceilings: Typically use 2 ceiling wires for support [independent from wires going to the grid] - connect to opposite corners. Screw fixtures to/through grid at opposing corners from the wires [if wire on left, screw on the right].
    Some LA County Inspectors [Building and / or Electrical] may require 4 wires and / or 4 screws. Last time I worked in La Mirada, we only needed to do 2 wires, 2 screws.
  • Other fixtures mounted to T-Bar Ceilings [Recessed Cans, Exit signs, etc.]:
    These will require box support, so the fixture and outlet box does not rely solely on the ceiling tile. They will also need 2 wires, which can be connected to the support mounting means, unless the fixture has provisions for them.
    Exit signs and other emergency egress lighting [other than troffers] may need to have the entire tile secured in place - possibly the surrounding tiles too! [had to do this in Manchester district and Westwood Village].
  • Hard Ceilings: Unless noted otherwise on your planset, these generally do not require ceiling wire supports.
  • Conduits and Raceways run above T-Bar ceilings:
    For any conduits run in the ceiling space [whips between fixtures, etc.], they shall not be secured to the wires supporting the T-Bar grid [main runners, seismic braces, etc.]. You will need to get some ceiling wires, then hang them yourself for your conduit runs [fixture whips close to the termination at the fixture may be able to use the independent fixture hanger wire, which you land a Caddy-Clip to].
    Terminate the loose ends of independent wires to the ceiling grid.


These items should do you fine, but if you aren't sure - check with the AHJ [City of La Mirada Building Department]. Ask them what they prefer.

Most California AHJs will apply the CBC [and in conjunction the CEC] to T-Bar Ceiling installations. These items I have listed are not in the NEC.

Before doing anything in the ceiling space, get a complete, full sized [D or E sized pages] and MOST CURRENT REVISION PLANSET!!! [not yelling, just a major headache area for me with the 7,000 rev. sets floating around a project!].
Look in the "A" sheets [Architectural] for the Reflected Ceiling Plan. There should be grid and suspension wire details on this page. If not, there should be some type of notation of what page it's on. Look for either a "Detail" callout line [circle with detail number above page number], or look in the title block. It would either be the page ahead of, or immediately following the RCP.

Lastly, look at the first page on the set - the one where the scope of work is noted. Verify the applical codes to this project. Also, if the TOC [Table Of Contents] is on that page, you might find the ceiling specs easier.

Good Luck!

Scott SET


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
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In addition to Scott's very correct & comprehensive post:
For exit, show window, etc. boxes in the T-bar ceiling, get the Caddy 512 series bar hangers designed for this purpose, they only require 1 support wire.
For any surface mounted fixtures, track, etc, the Caddy IDS series hangers are the way to go. They have a means for connecting a support wire to the top, and clip right around the grid.
Although it's not required unless you're above a fire rated ceiling, if you take a can of spray paint and spray your bundle of ceiling wires before you put them up it will make the wires you install easy to recognize, and should get a smile from your inspector.
Oh yes, also don't use toggles for support in the hard ceiling. Support any fixtures with screws to the structure.
Have a grand time!

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Thanks Scott for this information!


Joe Tedesco, NEC Consultant
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Thanks guys!

Out of curiosity, is any of this required retroactively in certain occupancies?
ie: Schools, Places of Assembly etc.?

Bill


Bill
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electure,

We spray painted wires on quite a few projects [glad you mentioned this in your post, as I forgot to include it]. Typically, we would use Blue paint for Comm/Data stuff, Yellow for Electrical [power and lighting], and Red for FLS conduits. Colors are normally user definable, and should not match colors which another trade has used [to my understanding...if not correct, let me know].

As you said, this might be required in certain areas, and it sure does make an Inspector smile!!

Thanks for picking up the areas I left out.

Joe,
You're very welcome! No problem at all!!

Bill,
No problem!
As to your Q':
Quote
Out of curiosity, is any of this required retroactively in certain occupancies?
ie: Schools, Places of Assembly etc.?

I think that through Seismic Retrofitting projects on stuff like Schools, Brick Buildings, Freeway Bridges, Etc., this would have been done. There was quite a lot of Earthquake reinforcement retrofit work going on after the 1994 Northridge quake.

Scott SET


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

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