I have yet to run into this on an LED retrofit, but are wondering if any of you out there have. I like using "Type B" double ended led retrofits. If using this type, the issue I see is that you would be running line voltage to the slave fixture through its existing cable assembly. I know some folks are weary of just putting line voltage on the tombstones on a regular retrofit, but I'm generally ok with that, assuming 120v, decent tombstones, and a sticker is affixed. This is taking it to a different level for me, though. Is this a Code or UL violation? Thanks!!!
LED Retrofit on Master/Slave Troffers
- Thread starter sauto
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James L
Senior Member
- Location
- Kansas Cty, Mo, USA
- Occupation
- Electrician
I worked in a 1930s school that originally had suspended T20 linear strips.
There were 4 in each row mounted to a spine. There was a single ballast on top of the spine, and load was daisy chained.
Never seen anything like it with T12 or T8
There were 4 in each row mounted to a spine. There was a single ballast on top of the spine, and load was daisy chained.
Never seen anything like it with T12 or T8
Yes, exactly. The master fixture has two ballasts in it. This setup normally, in my experience, has three lamps in both the master and the slave fixtures. One of the master’s ballasts powers up the outside lamps in each fixture. The other ballast in the master powers up the middle lamp in each fixture. The whip connecting the master to the slave is often more than 6 foot long; closer to 10 foot long, and looks like a typical fixture whip. I don’t have a setup in front of me, but I would bet 16 or 18 AWG sounds about right for the whip connecting the master to the slave. The slave fixture just has a male plastic connector that plugs into a corresponding female plastic connector on the end of the whip. I have literally installed hundreds of these in the last two decades in commercial applications! Perhaps they are not popular outside of where I work in Wisconsin? They are pretty handy as it cuts down on how frequently you have to spot a box for regular fixture whips, and I think they are quicker to wire.
Yeah in that case the ballast might have been providing some current limiting protection for the 18 AWG wires.
With the ballast removed now just are part of the branch circuit or are a tap:
210.19(A)(4) Exception No.2 gives the exception for fixture wires and sends us to 240.5.
240.5(B)(2)(1) might seem to allow it up to 50 ft.
I'd be more inclined to do it with 120V than 277.
I think I have seen that setup before, years ago. I see it allot in other applications like coolers in stores.
That seems to work, hopefully the AHJ thinks so too!
I like them too, at least with 120v and double ended. Even with spares, you know someone will put in a fluorescent tube in the future!I really like the Type B's. Just make sure you buy some spares and leave them on site
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