NEC 210.23 Lighting Branch Circuits

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bp8822

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I am looking for help on NEC section 210.23. I have a situation where I would like to place a lighting branch circuit on a 40A breaker (non-dwelling unit application). The fixtures are fluorescent type. The code mentions heavy-duty lamp holders, but I am unsure how this applies to a fluorescent fixture. Has anyone run into this situation previously that could provide some insight?
 
I believe that heavy-duty lamp holders refers to HID lighting, I guess you could interpret "other utilization equipment" to mean lights. I am curious why not a smaller circuit?
 
The fixture is a six lamp T5HO fixture. I can only place 3 fixtures on a 20A circuit. Since I have approximately 40 fixtures in a single space, I was trying to eliminate the number of branch circuits for control purposes. I am going to have to use a contactor in any case.
 
bp8822 said:
I am looking for help on NEC section 210.23.

The code mentions heavy-duty lamp holders, but I am unsure how this applies to a fluorescent fixture.
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210.23 does not apply, but rather 210.21(A).

The commentary (although NOT enforceable) following 210.21(A) states:
The intent of 210.21(A) is to restrict a fluorescent lighting branch-circuit rating to not more than 20 amperes because most lampholders manufactured for use with fluorescent lights are not of the heavy-duty type and are rated at 660 watts or 250 watts.
Branch-circuit conductors for fluorescent electric-discharge lighting are usually connected to a ballast rather than to lampholders, and, by specifying a wattage rating for these lampholders, a limit of 20 amperes is applied to ballast circuits.
Only the admedium-base lampholder is recognized as heavy duty at the rating of 660 watts. Other lampholders are required to have a rating of not less than 750 watts to be recognized as heavy duty. The requirement of 210.21(A) prohibits the use of medium-base screw shell lampholders on branch circuits that are in excess of 20 amperes.
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Other than the code rule, what does the socket have to do with this issue when it is on the load side of a current limiting ballast?
Don
 
I think that the commentary makes this issue clearer for me. Although it seems that it would be easier to state something clearer in the code. I spent some time looking over the fluorescent fixture cutsheets, but I could not find any mention of the rating for the lampholder. I guess essentially though it doesn't matter since the lamps are connected to the ballast. Also I failed to mention earlier that this is a 120V branch circuit in case anyone was wondering...

Thanks for the input...
 
don_resqcapt19 said:
Other than the code rule, what does the socket have to do with this issue when it is on the load side of a current limiting ballast?
Don
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Are you asking me, the OP or just throwing another log on the fire?
 
bp8822 said:
Also I failed to mention earlier that this is a 120V branch circuit in case anyone was wondering...
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I was, and is it possible for you to change this? Many modern ballasts can accept a voltage range, even up to 277.

As for switching a large number of circuits, it can be easier and more economical to switch an entire panel with a contactor.
 
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