410.16 - Means of Support

[steve66]

If a 2x4 fixture is hung from two support wires at diagonal corners, and the fixture is placed in a ceiling grid, does the fixture still have to be attached to the grid??

Local inspector says yes. I think that the two wires are an independent support, and 410.16 does not apply.

Steve

 

[jbwhite]

Re: 410.16 - Means of Support

I have usually used ceiling wire on two corners, and the pull out clips that are intergral to the fixture.

 

[charlie b]

Re: 410.16 - Means of Support

I don't see anything that says you can use an independent support, in lieu of the requirements of 410.16(C). Lacking another permissive statement, I would have to agree with the Inspector.

 

[pierre]

Re: 410.16 - Means of Support

Steve
I agree that 410.16 does not apply in your installation, as your fixture(s) are not supported by the ceiling grid.

The only other issue you may have to deal with is the local codes.

 

[Tom.Margillo]

Re: 410.16 - Means of Support

Maybe there are seismic requirements involved.

 

[JES2727]

Re: 410.16 - Means of Support

Until recently, inspectors in my area (central NJ) accepted the wires in opposite corners as adequate support. However, as its been explained to me, the ceiling wires are required by the building code, not the NEC. This does not relieve us of the requirements of 410.16. So now they require both. It's redundant and wasteful and everybody knows it. But it's required.
Also, in this area they do not accept the built-in fixture clips - "too flimsy". They require tek screws or the Caddy type fixture clips (known as "hurricane clips" in these parts).

John

 

[steve66]

Re: 410.16 - Means of Support

There aren't any additional local codes, just the NEC.


Posted by Charlie B.:

I don't see anything that says you can use an independent support, in lieu of the requirements of 410.16(C).

The 2002 handbook says "Where luminaires are supported independent of a suspended ceiling, 410.16(C) does not apply."

But I have to agree that the second sentence of 410.16(C) seems to have no qualifiers. It says:
"Luminaires shall be securely fastened to the ceiling framing member by mechanical means such as bolts, screws, or rivets." That sentence doesn't seem to have any if's, or's, but's or exceptions to it.

Steve

 

[jbwhite]

Re: 410.16 - Means of Support

I dont see two tie wires in opposite corners as being "supported independent of the ceiling" The wieght of the fixture is still on the ceiling.

I have supported smaller fixtures, independant of the ceiling off of octogon boxes mounted with thread rod to the structural ceiling.

I dont think the requirement is redundant. In school the instructor explained that this is because a fireman will tear out the ceiling tiles with a hose or rake in the event of a fire and the wires are to keep the lights from falling on his head.

 

[pierre]

Re: 410.16 - Means of Support

The NEC is a permissive document -this has been stated many times before, so it is not so much of a surprise.

410.16(C) does not say "shall be", "shall be required" or any other mandatory language, it uses language of the sense that if the ceiling grid is used, one will need to follow the requirements of (C).

How many times in the past has chain, ceiling wire, rod and other means been used to support the layin type fixtures.
I could not find any reference in the NEC that did not permit the above methods from being used.

Also remember, that the fire department wants to be assured that the fixtures will not come down when they are pulling on the ceiling grid.

 

[jbwhite]

Re: 410.16 - Means of Support

"(C) Suspended Ceilings. Framing members of suspended ceiling systems used to support luminaires (fixtures) shall be securely fastened to each other and shall be securely attached to the building structure at appropriate intervals. Luminaires (fixtures) shall be securely fastened to the ceiling framing member"

I say that two ceiling wires on a fixture do not SUPPORT the fixture, they back up the support in case of a fire.

 

[lawelectric]

Re: 410.16 - Means of Support

Diagonal ceiling wires are just seismic, you will still have to attach the fixture to the grid (i.e. the pop tabs)

 

[iwire]

Re: 410.16 - Means of Support

If your under the NEC I agree with Charlie.

I don't see anything that says you can use an independent support, in lieu of the requirements of 410.16(C).

If you happen to be in MA things change.

410.16(C). Add a second paragraph as follows:

In addition to, or in lieu of, the mechanical fastening means, electric luminaires (fixtures)containing ballasts, other than simple fluorescent reactance ballasts, shall be supported directly to the building structure by wire, chain, or threaded rod of sufficient strength to carry the luminaire (fixture). Fluorescent luminaires (fixtures) shall be supported at each end of a diagonal axis of the luminaire (fixture).

 

[benaround]

Re: 410.16 - Means of Support

It would be nice to know the intent and the 'why' of this.
Firemen have told me they like the way the fixture holds the main grid runners when screws,etc. are used!

 

[pierre]

Re: 410.16 - Means of Support

Show me where the NEC says you cannot use chain, rod, or even wire of some sort to support fixtures. How about "Chicago bar"? I would like to see it in writing, section number, etc...

If not diaginal, how about all four corners?


"Diagonal ceiling wires are just seismic, you will still have to attach the fixture to the grid (i.e. the pop tabs)"

What document did you get this information from?

 

[iwire]

Re: 410.16 - Means of Support

Originally posted by pierre:
Show me where the NEC says you cannot use chain, rod, or even wire of some sort to support fixtures. How about "Chicago bar"? I would like to see it in writing, section number, etc...

You can use all of those methods..however none of that relieves us under the NEC to comply with "Luminaires (fixtures) shall be securely fastened to the ceiling framing member by mechanical means such as bolts, screws, or rivets."

IV. Luminaire (Fixture) Supports

410.16 Means of Support.

(C) Suspended Ceilings. Framing members of suspended ceiling systems used to support luminaires (fixtures) shall be securely fastened to each other and shall be securely attached to the building structure at appropriate intervals. Luminaires (fixtures) 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) [fixture(s)] shall also be permitted.

Even the last sentence

Listed clips identified for use with the type of ceiling framing member(s) and luminaire(s) [fixture(s)] shall also be permitted.

Is talking about securing the fixture to the grid not the fixture to the building structure.

 

[pierre]

Re: 410.16 - Means of Support

I have read this part of the paragraph before Bob. I read it as a continuation of the first sentence. Meaning that the first sentence permits the ceiling frame as a support (if used), and if you do use it as a support, follow the requirements of the second sentence.


"Framing members of suspended ceiling systems used to support luminaires..."

I do not see where there is any mandatory language here as relates to the luminaires having to be supported to the grid.


I would still like to see where the NEC prohibits support by other means, such as posted earlier.

[ December 28, 2005, 08:03 PM: Message edited by: pierre ]

 

[peter d]

Re: 410.16 - Means of Support

Pierre,

I don't agree. The fixtures are being supported by the grid whether they have independent support wires or not. If they do have indpenedent wires, the grid is still serving to support the fixture and keeping it in place.

I agree with Bob and Charlie.

 

[JohnE]

Re: 410.16 - Means of Support

I agree with Pierre. In order to double check I checked the '02 handbook which was handy, and presuming nothing has changed in '05 then part of the commentary specifically addresses this exact situation. It says, in part, "when luminaires are supported independant of a suspended ceiling, 410.16(C) does not apply".

 

[peter d]

Re: 410.16 - Means of Support

The handbook is simply someone's opinion. I don't take it greater than anyone's opinion here.

And I don't agree with the handbook. I still say that the ceiling grid does provide support for the fixtures even with independent wires attached.

 

[iwire]

Re: 410.16 - Means of Support

Originally posted by pierre:
I have read this part of the paragraph before Bob. I read it as a continuation of the first sentence.

I respectfully suggest that is not the case at all.

IV. Luminaire (Fixture) Supports

410.16 Means of Support.

(C) Suspended Ceilings. Framing members of suspended ceiling systems used to support luminaires (fixtures) shall be securely fastened to each other and shall be securely attached to the building structure at appropriate intervals.

IMO that is one requirement of the section.

The grid that is supporting a fixture shall be secured to the structure.

Than a separate issue is the securing of fixture to the grid regardless of the grid supporting them or not.

Originally posted by pierre:
[QB]Luminaires (fixtures) 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) [fixture(s)] shall also be permitted.

In the first section the subject is the grid itself.

In the second section the subject changes to the fixtures.

I do not see how the first is a continuation of the second.

JMO, Bob