n8welch
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- Chesapeake VA
I am aware of the 6' rule but is there a limit as to how many daisy chained lights you can have on one circuit. We are using 277v
Daisy Chaining Floresent lights (commercial)
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n8welch
Member
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- Chesapeake VA
six foot whips
I believe he was referring to 410.117(C) regarding fixture "tap" conductors. This applies if you use the facyoty whips that have the smaller conductors in them, it would not apply if you are "daisy-chaining" a bunch of fixtures using any other wiring method.
kwired
Electron manager
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- NE Nebraska
He could be questioning the use of flexible metal conduit as an equipment grounding conductor also. The basic rule is no EGC path can be made up of more than 6 feet of FMC. You could have a junction box with four 6 foot lengths of flex being used as the EGC going to individual luminaires from the box. You can not jump between four luminaires with three 6 foot lengths of flex being used as the EGC.
As for pre made whips with 16 or 18AWG conductors - those have a listing, see the instructions that are part of the listing. You likely can not daisy chain them.
As for pre made whips with 16 or 18AWG conductors - those have a listing, see the instructions that are part of the listing. You likely can not daisy chain them.
n8welch
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- Chesapeake VA
We are using 12/2 with a ground MC. They are not pre made. I was thinking in school my instructor had said they coulg be made no longer than 6'. Also this is commercial instalation is that makes and difference.
Since you're using MC you can make them as long as you want, be it in commercial, residential, or industrial applications. The only thing that would come into play if you made one a few hundred feet long would be voltage drop.
Roger
n8welch
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- Chesapeake VA
Ok. Where do you think I am getting this six foot thing from? I could have swore it was mc whips.
I don't know where you would have gotten that idea but, MC is a wiring method that can be used for complete branch circuits and feeders and there is no limitation to how long a run can be. Did you read the article section posted by jjohnson, that is for factory whips with tap conductors, may be your teacher was speaking of that.
And as kwired mentions, if you look at 250.118 FMC has a 6' limitation if you are using it for an EGC.
There is one more thing that could possibly be where you got the 6' idea, 3/8" FMC is also limited to 6' lengths, see 348.20
Roger
The 6' thing may also stem from length permitted to be unsupported.
hillbilly1
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I think so too, like drops to 2X4 lay ins.
kwired
Electron manager
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- NE Nebraska
Does not need to be lay in for that rule to apply.
hillbilly1
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- Semi-Retired Electrician
There are similar requirements/exceptions listed for both FMC and MC where the 6' length is mentioned. These were previously mentioned, such as permitted to be unsupported for max 6' from last point of securing. Also you might be thinking of 410.117(C) for tap conductors to lights in MC or AC to not be more than 6'.
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Either from "no longer than 6' on FMC without and EGC" (I think that changed and you need an EGC for any length) or "no longer than 6' on a #18 fixture whip".
20 some years ago I had an inspector who was VERY adamant that I couldn't run metallic LT longer than 6' even though I had an EGC in it.
20 some years ago I had an inspector who was VERY adamant that I couldn't run metallic LT longer than 6' even though I had an EGC in it.
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