Chain hung fixture wiring

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tkb

tkb

Senior Member
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MA
I am starting a job that has chain hung 8'fluorcesent fixtures connected together with 1/2" EMT about 8' apart.
The fixtures hang about 10' from the roof.
The EMT is unsupported.
Aside from the violation of NEC 358.30A is it OK to connect chain hung fixtures with EMT end to end?
I am trying to get them to let me rewire the rows with MC cable and then drop down the chain from a new box with MC to connect the fixtures.
I can't find any reference to this in the NEC or Mass electric code but I know it's not right.

Anyone have any opinions? :confused:

Thanks
Tim Bridge
 
Re: Chain hung fixture wiring

8' Strip fixtures. You know the cheap ones with the ends that you just bang the tab into the slot with no screws.
The fixtures are hung down about 10' from the roof fed with MC from a box mounted on the z perlin and then 1/2" emt between the fixtures about 8 to 10' long.
 
Re: Chain hung fixture wiring

EMT has to be supported withing 3 ft of the connector to the bang in end plate.
Why not pipe emt on the ceiling, put in a box and run a whip down to each chain hung fixture?

[ October 22, 2004, 02:36 PM: Message edited by: tom baker ]
 
Re: Chain hung fixture wiring

I'm sorry but I wasn't clear.
What I described is the existing installation.
I would be removing these fixtures and want to replace all of the wiring and whip down the chain with MC cable.
What my question is what makes this installation illegal besides the support 3' from the fixture.
I am trying to justify the extra costs to the owner.
 
Re: Chain hung fixture wiring

The support of the EMT. Also, what keeps the ends from popping out if the fixtures sway on the chain? I don't think the fixtures are designed (listed) to be installed that way. They are designed to be installed end-to-end with a chase nipple and all will have some kind of tab arrangement to lock them together without relying on the end plates.

-Hal
 
Re: Chain hung fixture wiring

Originally posted by hbiss:
Also, what keeps the ends from popping out if the fixtures sway on the chain? I don't think the fixtures are designed (listed) to be installed that way. They are designed to be installed end-to-end with a chase nipple and all will have some kind of tab arrangement to lock them together without relying on the end plates.
-Hal
Click to expand...
Hal I would have to disagree with that as many of these fixtures come with either hooks or holes for jack chain supports.

Personally I typically put a tek screw in the end plates after snapping them in. Many of the fixtures come with pre-punched holes for screwing the end plates on if used as a cap or coupling when running fixtures end to end.

That said I agree with the others that the EMT is required to be supported by something other than the fixtures. I have seen it done with minnis supported by jack chain, if that is OK or not is really up to the inspector to decide.

By the way... Hi Tim how you doing? :cool:
 
Re: Chain hung fixture wiring

...many of these fixtures come with either hooks or holes for jack chain supports.

Right. Nothing wrong with hanging the fixtures with jack chain.

Personally I typically put a tek screw in the end plates after snapping them in. Many of the fixtures come with pre-punched holes for screwing the end plates on if used as a cap or coupling when running fixtures end to end.

The key words here are end to end. As you say most fixtures will have means to fasten the fixtures together if butted end to end. All the ones I have seen do this by fastening the fixtures themselves, not the end plates, creating one rigid assembly.

I suppose you could provide your own means to fasten the end plates but this is not per manufacturers design especially if the end plates were used to support conduit.

-Hal
 
Re: Chain hung fixture wiring

Hal I guess we will have to disagree.

I have never seen instructions one way or the other explaining the 'listed' methods of installing these fixtures.

The knock outs on any equipment are not supposed to support the raceway, that is the job of the required support. :)

Bob
 
Re: Chain hung fixture wiring

I was on a job where we ran strut the whole length of the row, hung the lights to the strut, and we could put mini s on the emt and hook to the strut for support. Made for a real nice job.
 
Re: Chain hung fixture wiring

Originally posted by frankft2000:
I was on a job where we ran strut the whole length of the row, hung the lights to the strut, and we could put mini s on the emt and hook to the strut for support. Made for a real nice job.
Click to expand...
It does look great that way. :)
 
Re: Chain hung fixture wiring

hung the lights to the strut, and we could put mini s on the emt and hook to the strut for support.
Click to expand...
If you run strut the whole length, why not use it as the raceway and eliminate the EMT?
Don
 
Re: Chain hung fixture wiring

The knock outs on any equipment are not supposed to support the raceway, that is the job of the required support.

Then we do agree! :)

I also agree with using strut, that's a real nice way to do it and the thought had occurred to me but it's more money than running MC up, over and down.

-Hal
 
Re: Chain hung fixture wiring

Thanks to all that have responded.

Hi Bob and Al. It's good to see some of my old friends.

OK we agree that you can hang the fixtures by chain and the conduit must be supported 3' from the connector. How about exception #1 to 358.30(A)that extends the distance to 5' where there is no structural members readily available. What would be readily available meen to the inspector. Also is chain to a minerlax a support for EMT?

The only instructions that come with the fixtures are for the grounding screw which are printer on the box.

As far as screwing the end plates on, wouldn't the fixtures be supplied with the screws if the tab wasn't sufficient to meet their UL listing?

I thought that chain hung fixtures and rod hung heaters and the like must be connected with a flexible method. I cannot find this in the NEC. Maybe this is just good wiring practice that we have been taught over the years.

As far as the strut, while this is a very good method it is also expensive. This would cost more than the fixtures themselves.
 
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