Hard piping a chain hung fixture?

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Bloose

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Hello all,

We are installing about 300 8 foot fluorescent fixtures in an industrial facility. The fixtures are hung from around 12" of chain. The spec for the fixture layout indicates that the fixtures should be hard piped (EMT), even though they are hung from chain. To me this is not only bad design but I have always thought that if an item being piped will move it had to have some sort of flexible wiring or raceway, I.E. cord, greenfield, sealtite, etc. When I brought it up I was told to show in the code where it was not allowed. I have looked but I cannot find anything. I know this is a bad idea, but is there someplace in the code that I can point out that doesn't allow it?

Thanks
 
Assuming you go ahead with it how would you meet 358.30(A) requiring EMT to be both supported and secured?

Often what I see done is a continuous row of uni-strut run at the fixture height, both the fixtures and the EMT would be secured to the strut, or if you buy the right type of strut it can be the raceway.
 
the only thing i can think of is the 'neat and workmanlike manner' and the other article (and this is a STRETCH) is 300.11 (2002 code) My 05 code is out in the car ;) Everything has to be securely in place, so with the emt going to it and there is slight movement on the chain hung fixture, then it will loosen the connections. I have seen many of fixtures ran with hard pipe that were hung from a chain, but i agree with you it needs to be some flexibility to it in my opinion. ;)
 
iwire said:
Assuming you go ahead with it how would you meet 358.30(A) requiring EMT to be both supported and secured?

Often what I see done is a continuous row of uni-strut run at the fixture height, both the fixtures and the EMT would be secured to the strut, or if you buy the right type of strut it can be the raceway.
Click to expand...

There will be no problem supporting the pipe within 3' of the fixture. I just really think it's a bad idea to bring a hard pipe to a fixture that is essentially floating. So bad in fact I've never done it and I guess I thought it would have been addressed somewhere in the code and I was just missing it. In time the fittings will be loose and the fixture sheet metal will be bent. I guess this falls under the fact that the code is the minimum requirement but doesn't necessarily represent good design.

I'm hoping to talk them into putting a 4" on the beams at each fixture location and running a lighting whip to each fixture. A twist lock at each location would be even nicer and would facilitate easier repair and replacement but I know they don't want to spend the money.

Thanks
 
300.11 says that electrical equiptment must be securely fastened in place. This refers to the fact that it must be both horizontally secure and vertically secure. Then in 358.12(5) it says EMT cannot be used to support fixtures. So that in this situation of a chain hung fixture the chain is providing verticle support and the conduit is proving horizontal support, which would not be allowed. Does that line of thinking make any sense?

Thanks
 
Thanks to those who replied. I was able to talk them into running greenfield from a 4" box to each fixture. It's turning out nice and is a much better option if you ask me than hard piping.

B-loose
 
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