13ft chain pendant fluorescent

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banelec

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Guys,
Power is at the ceiling in a bus depot. They want to hang T5 4ft fixtures 13 ft down from the ceiling on chain.
How would you wire it?

( fixture is replacing an existing HID which is on a 10ft 3/4" RMC pendant with a swivel at the ceiling)

Does tiewrapping FMC to chain count as support or am I limited to the 6ft rule?
(I would still use stranded wire)

Can I extend the 3/4" past 10ft or is there a 10ft rule for pendants (I have seen 20ft pendants)?

How do you feel about supporting a fixture with the 3/4" pendant and a chain- it looks wrong but is it, if the pendant is on a swivel?

Frank
 
try reading 314.23(H) for th pendant issue you can judge best if our installation complies with that section.

250.118(5) limits the ground path to 6 feet not the length of the nstallation. If you include an egc with the installation the lenght is not restricted, although other considerations in 348 may apply
 
If you use FMC it would need to be 1/2" or larger. 3/8" is limited to 6' in length.
 
13ft chain pendant fluorescent

Thanks for the responses guys.
It is the interpretation of some of the code sections that gets me.
Option a: So 1/2" FMC with stranded THHN including a ground wire tiewrapped down the chain for support is good for any length.

Does anyone think it is not?

option b: Looking at 314.23 (H). I think I can extend the RMC pendant as long as I can get a threaded couping with locking screws, and if the fixture has a threaded hub with a locking screw. As the fixture hub is in the center I would have to put 2 chains.
However the idea of locking screws is to stop it from spinning off the threads. It cannot spin if there is a chain at the other end so maybe I can attach the conduit through a knock-out at one end and put a chain on the other.


Manufacturers are telling people that their 4ft fixtures can be hung from the single pendant with the hub they have in the back of the fixture, but this seems to be in violation of the " 12" in any horizontal direction from the point of entry" rule.


Frank
 
Firstly...yes, if you put a ground in the greenfield you are not limited in length. You can run any length down to your light.

Your other solution is also viable, however with a LOT more cost. If you can do it legally and safely with the FMC, why consider a more expensive option?

We are in this to make money for our bosses, who in turn keep us employed right?
 
I wasn't disputing that they made stranded conductor MC cable...I was wondering what application would warrant ordering stranded MC vs. solid conductor MC?
 
13ft chain pendant fluorescent

icefalkon said:
I wasn't disputing that they made stranded conductor MC cable...I was wondering what application would warrant ordering stranded MC vs. solid conductor MC?
Click to expand...

The stranded versus solid wire was debated at the following thread:

http://forums.mikeholt.com/showthread.php?t=113181&highlight=stranded

The argument is whether the following applied:
410.56 Protection of Conductors and Insulation.
(E) Stranding. Stranded conductors shall be used for wiring on luminaire chains and on other movable or flexible parts."

The easy call, is to use stranded and not have it questioned later.

If solid was OK, then AC cable would be easier to install, (no EGC to find a termination point for at the old outlet box.)

Frank
 
I would use MC. Since I have a roll of stranded in the van, I would use that. Most times I have solid in the van, so I wouldn't hesitate to use that, either.
 
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