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New tool
by SMOKEYBOB - 02/15/21 04:59 PM
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Light fixture support
#167515
08/14/07 08:04 PM
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Joined: Apr 2002
Posts: 32
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I'm installing 8 ft plug in fixtures in a large retail commercial building (28 per row). Is there any spec as to the spacing of supports?
Bill
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Re: Light fixture support
[Re: sudsy4]
#167533
08/15/07 06:06 AM
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Joined: Apr 2002
Posts: 7,233
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Best answer may be: Check mfg specs or Apply common sense. 8' fluor channel fixtures are surface mounted at 3 points; suspended at 2 points (each fixture) It's a 'no definite' answer as the layout is vague by your description above.
John
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Re: Light fixture support
[Re: HotLine1]
#167537
08/15/07 06:35 AM
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Joined: Nov 2006
Posts: 348
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The only rule I know of is 110.3 (B)...well that and 110.12
101° Rx = + /_\
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Re: Light fixture support
[Re: sudsy4]
#167539
08/15/07 06:44 AM
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Joined: Jan 2003
Posts: 4,391
Moderator
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With hanging 8' strip lights I usually support the first one at both ends and the far end of each succeeding one. Here is a job I finished last year, almost 600 fixtures. ![[Linked Image]](https://www.electrical-contractor.net/forum/iw/Jo-Ann-Lights.jpg) That said I recently hung some 8' custom linear lights in offices and that jobs foreman had me do the same as I described above. IMO the fixtures being cast where to week for that and should have had three supports a piece for each fixture as they had been designed. I guess what I am saying is follow Johns advice.....apply common sense.
Bob Badger Construction & Maintenance Electrician Massachusetts
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Re: Light fixture support
[Re: iwire]
#167576
08/15/07 06:46 PM
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Joined: Apr 2002
Posts: 7,233
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Bob: NICE.... BTW, quite a while back...like you said, 2 on the first; chase nip/ln thru end ko's, one on each additional. I didn't want to write a novel on the many ways.... Now the 'old' 8' INdustrial type with the full reflector shade...nice old heavy mag ballast, and a housing made from real live steel, not recycled Pepsi cans (man's fixture), that was a definite 'two chainer'.
Back to my serious mode....any shot to get good old common sense into the NEC??
Stay safe
John
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Re: Light fixture support
[Re: sudsy4]
#167584
08/15/07 09:23 PM
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Joined: Apr 2002
Posts: 32
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Thanks for the input everyone. I agree on the 2 on first fixture then one a foot or so from the end of all the rest; however, bar joists don't fit that senario. I guess my actual question was can you miss a hanger on a fixture or must you have a support on every fixture? Checked manufactures specs, told me nothing. The store is a Wal-Mart Superstore.....many many fixtures.
Bill
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Re: Light fixture support
[Re: iwire]
#167585
08/15/07 09:28 PM
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Joined: Apr 2002
Posts: 32
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Thanks for the pics...nice job
Bill
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Re: Light fixture support
[Re: sudsy4]
#167604
08/16/07 06:28 AM
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Joined: Apr 2002
Posts: 7,233
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Bar joist locations not 'matching' a place for a support are solved by bridging b'twn bar joists with strut, or another suitable alternate. What about the plans/specs? Most, if not all will provide a detail on the REQUIRED method of installation by the Architect/Engineer of record.
Your 'client' is not a small operation, so you should have details available, or submit an RFI.
John
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Re: Light fixture support
[Re: sudsy4]
#167617
08/16/07 02:52 PM
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Joined: Jan 2003
Posts: 4,391
Moderator
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I guess my actual question was can you miss a hanger on a fixture or must you have a support on every fixture? I would not skip a support, as John mentioned you need to come up with a way to get a support where you need it. In my picture above out of over 600 supports only a few actually land on a truss. If you notice the fixtures are diagnal...a major pain in the rear. Anyway we used these from Caddy... ![[Linked Image from erico.com]](http://www.erico.com/public/images/products/FF-Electrical/NorthAmerica/PH1143.jpg) ![[Linked Image from erico.com]](http://www.erico.com/public/images/products/FF-Electrical/NorthAmerica/14441445.jpg) To install most of them you use this tool... ![[Linked Image from erico.com]](http://www.erico.com/public/images/products/FF-Electrical/NorthAmerica/IL2492.jpg) But before we got started I sent an RFI to the engineer asking if this method of supporting from the deck was OK. He approved it and away we went. I can tell you these are very strong. BTW, also the fixtures in the above photos are joined with factory couplers with 4 tek screws added per coupling to ensure the fixture could not pull apart and drop.
Bob Badger Construction & Maintenance Electrician Massachusetts
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Re: Light fixture support
[Re: iwire]
#167632
08/16/07 06:17 PM
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Joined: Jul 2004
Posts: 9,569
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How does this grab the deck?
Greg Fretwell
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