Support for can lights in a suspended ceilings

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whitecat@eatel.net

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I have been a journeyman wireman for a little over two years and am fairly new to commercial work. I am currently working in a hospital setting and was assigned to install can lights in the lobby area where the ceiling will be grid and tile. In addition to the traditional method of support (Ramsets and tie-wire from the hard ceiling), my apprentice and I have been tying the support arms of each light to the grid as well. This "extra" step came about as a means of holding the fixture down while inserting the trim. Another journeyman commented that wiring to the grid was against code, but I can find nothing to support his statement. I can understand his concern if the hard ceiling support was not in place, but otherwise I see no problem. So, am I violating the NEC by adding this extra step?
 
Article 410.16(C) covers supporting light fixtures in suspended ceilings. Screws, rivets, bolts,and listed clips can be used according to the nec.Tie wire isn't listed in the article.
Rick
 
RUWired said:
Article 410.16(C) covers supporting light fixtures in suspended ceilings. Screws, rivets, bolts,and listed clips can be used according to the nec.Tie wire isn't listed in the article.
Rick
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It says it shall be attached by a mechanical means to the grid such as rivets, bolts screws...

It does not exclude tie wire. By definition, tie wire falls under mechanical means of support.
 
RUWired said:
Article 410.16(C) covers supporting light fixtures in suspended ceilings. Screws, rivets, bolts,and listed clips can be used according to the nec.Tie wire isn't listed in the article.
Rick
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Just because it doesn`t say you can use that means .Does that say that you can`t ????? IMO the separate support is a fire issue.That way when the FD comes in during a fire they don`t have fixtures that might be still live falling on them from above.After all fire/water/electricity are a bad combo.especially combined.If there is an NEC issue on this I am sure the inspector will pick up on it.
 
Tie wire is whole lot cheaper than specialty straps. It's like a gorrilla. " It ain't pretty, but it sure is strong"
 
adding an extra step is in my opinion(opening up a can of worms)over an above what is already required.If the light is attached to the hard ceiling were is it going to go.
 
I don't hang a lot of can lights in a suspended ceiling...but...If you attach the can lights to the ceiling grid, aren't you defeating the purpose of the independant fixture support?
Where is the line between fixture support and ceiling grid support?
I mean, if the ceiling gets really heavy from water (fire department), won't the weight of the ceiling be bearing directly on the can light suppports?
If the grid supports fail, the cans will probably come down too.
Just a thought
steve
 
To clarify my answer the attachment to the hard ceiling will hold up the light. the requirement for attachment to the grid is only if you are using it as the soul support for the light.
 
One of the reasons that you support fixtures to the t-bar grid is that in an earthquake things of different weights and sizes will move with different frequencies.

so as a 2 x 4 fixture is coming down and the grid is moving up the fixture tends to beat the grid apart. If you connect everything then it will move as a unit limiting the damage.

The support wire is simply to keep the fixture over head and doesn't give any support what so ever. It's simply acting as a safety harness.
 
You have (2) options:

1. Support the light from the structure like you have been doing. In this case, nothing prevents you from securing the lights to the ceiling grid. (So I guess you really have 3 options:) ) And 410.16 does not even apply. You aren't using the ceiling to support the lights, you are using the structure above.

2. Just support the lights on the grid.

I don't see anything wrong with what you are doing.

STeve
 
cowboyjwc said:
One of the reasons that you support fixtures to the t-bar grid is that in an earthquake things of different weights and sizes will move with different frequencies.

so as a 2 x 4 fixture is coming down and the grid is moving up the fixture tends to beat the grid apart. If you connect everything then it will move as a unit limiting the damage.

The support wire is simply to keep the fixture over head and doesn't give any support what so ever. It's simply acting as a safety harness.
Click to expand...

I never thought of that. Good point to ponder.
I learned something today.
steve
 
inspector12 said:
To clarify my answer the attachment to the hard ceiling will hold up the light. the requirement for attachment to the grid is only if you are using it as the soul support for the light.
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Exactly !
410.16(C) Suspended Ceilings. . Framing members of suspended ceiling systems used to support luminaires .....
If the light isn't supported by the grid ceiling, 410.16(C) says that is doesn't apply.
 
dnem said:
Exactly !
410.16(C) Suspended Ceilings. . Framing members of suspended ceiling systems used to support luminaires .....
If the light isn't supported by the grid ceiling, 410.16(C) says that is doesn't apply.
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Name some of the ways that a fixture is not supported by the ceiling grid.With troffers and cans, unless its on a strut rack or fastend to the structure, the grid is the support and 410.16(C) applies.

I should have originally said that tie wire is generally excepted, and when using hid fixtures a piece of pipe is used to support the fixture to the grid and tie wire is an easy way to secure it, but i did'nt because so many times a hole does'nt line up with the hanger and is left undone.If screws were used, the fixture would fit flat against the tile and the screws would secure it properly.Also if this was a troffer, then tie wire would hardly work.
Rick
edited to say secure
 
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RUWired said:
Name some of the ways that a fixture is not supported by the ceiling grid.With troffers and cans, unless its on a strut rack or fastend to the structure, the grid is the support and 410.16(C) applies.
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It's very common for contractors in my area to choose to independently support the lights from the hard ceiling. . Support wires directly to the light that are separate from the ceiling grid support wires.
 
dnem said:
It's very common for contractors in my area to choose to independently support the lights from the hard ceiling. . Support wires directly to the light that are separate from the ceiling grid support wires.
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Yes,Very common around here and what is needed to pass inspection without trouble. My point was,( when you said exactly !) , even with those auxillary support wires, do they actually support the fixture. I see different contractors throw a wire through the joist and attach it to opposite corners. Are 2 wires a support or are 4 wires a support, I would say the ceiling grid supported the fixture and the wire was an extra safety measure,(usally a specification).I also see the same wires used to support the branch wiring.Technically the seperate grid wire support for the branch wiring needs to go to the grid.

Is it code to use auxillary wires as support or generally excepted.
 
I do alot of commercial work. We have always asked the AHJ what they require. You can support the fixture by the grid but not alone, some want a tywire ( same as the grid wire ) some want 2 corners some want 4, some want jack chain, some want aircraft cable. Its all up to the AHJ because he is in tune with the fire marshall of that town or city. It may be a BOCA code but its to protect the fireman when they come in with their hooks to rip the ceiling. This has been my experience that I have done for years.
 
RUWired said:
Yes,Very common around here and what is needed to pass inspection without trouble. My point was,( when you said exactly !) , even with those auxillary support wires, do they actually support the fixture. I see different contractors throw a wire through the joist and attach it to opposite corners. Are 2 wires a support or are 4 wires a support, I would say the ceiling grid supported the fixture and the wire was an extra safety measure,(usally a specification).I also see the same wires used to support the branch wiring.Technically the seperate grid wire support for the branch wiring needs to go to the grid.

Is it code to use auxillary wires as support or generally excepted.
Click to expand...

410.16(C) uses words like ?support? and ?secure? which results in a thousand and one different interpretations. . Some AHJs would agree with your statement, ?Are 2 wires a support or are 4 wires a support, I would say the ceiling grid supported the fixture and the wire was an extra safety measure?. . In my department, we don?t consider direct wires to the light to be independent support until there are at least 3 wires on 2x2s and 2x4s and one centered wire on recessed cans.

But the biggest issue is what Dean brought up

Dean83169 said:
I do alot of commercial work. We have always asked the AHJ what they require. You can support the fixture by the grid but not alone, some want a tywire ( same as the grid wire ) some want 2 corners some want 4, some want jack chain, some want aircraft cable. Its all up to the AHJ because he is in tune with the fire marshall of that town or city. It may be a BOCA code but its to protect the fireman when they come in with their hooks to rip the ceiling. This has been my experience that I have done for years.
Click to expand...

The fire department has requirements. . In our case, we?re a county building department that covers a whole county minus 2 cities. . Our jurisdiction covers 17 townships, 6 villages, and one city. . So that?s 24 different fire departments.

All of these departments are OK with our requirements. . To be considered supported we look for at least 3 wires on 2x2s and 2x4s and one centered wire on recessed cans directly to the light. . Or at least 3 wires supporting the grid within 6 inches of the fixture and the fixture screwed or clipped to the grid.

Like Dean said, the only sure way is to ask ?the AHJ what they require?.

David
 
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