Lighting

[weressl]

It looks like 210.21(B)(3) Exception 2 and 410.30(C)(2) will allow the 30 amp circuit to supply 15 or 20 amp receptacles that supply HID fixtures. (2005 NEC)

Yep, that clenches it.

 

[iwire]

Yep, that clenches it.

For what it's worth IMO nothing in 240.21(B) applies here, there is no 'feeder' it's a branch circuit so 210.21(A) sends us to 210.19 and onto 210.19(A)(4). :smile:

 

[haskindm]

It looks like 210.21(B)(3) Exception 2 and 410.30(C)(2) will allow the 30 amp circuit to supply 15 or 20 amp receptacles that supply HID fixtures. (2005 NEC)

Iwire,
I agree with what you say, as long as it is an electric discharge lighting fixture with a Mogul base bulb per 410.30(C)(2). The OP referred to T5HO fixtures, which I assumed are fluorescent lights. I cannot see any provision in the NEC that would allow fluorescent tube type lights to be installed on a 30-amp circuit. Am I missing something or have I misinterpreted what a "T5" fixture is?

 

[weressl]

Iwire,
I agree with what you say, as long as it is an electric discharge lighting fixture with a Mogul base bulb per 410.30(C)(2). The OP referred to T5HO fixtures, which I assumed are fluorescent lights. I cannot see any provision in the NEC that would allow fluorescent tube type lights to be installed on a 30-amp circuit. Am I missing something or have I misinterpreted what a "T5" fixture is?

From the MSEncarta encyclopedia:

The fluorescent lamp is another type of electric-discharge device used for general-purpose illumination. It is a low-pressure mercury vapor lamp contained in a glass tube, which is coated on the inside with a fluorescent material known as phosphor. The radiation in the arc of the vapor lamp causes the phosphor to become fluorescent. Much of the radiation from the arc is invisible ultraviolet light, but this radiation is changed to visible light if it excites the phosphor. Fluorescent lamps have several important advantages. By choosing the proper type of phosphor, the light from such lamps can be made to approximate the quality of daylight. In addition, the efficiency of the fluorescent lamp is high. A fluorescent tube taking 40 watts of energy produces as much light as a 150-watt incandescent bulb. Because of this illuminating power, fluorescent lamps produce less heat than incandescent bulbs for comparable light production.

 

[haskindm]

From the MSEncarta encyclopedia:

The fluorescent lamp is another type of electric-discharge device used for general-purpose illumination. It is a low-pressure mercury vapor lamp contained in a glass tube, which is coated on the inside with a fluorescent material known as phosphor. The radiation in the arc of the vapor lamp causes the phosphor to become fluorescent. Much of the radiation from the arc is invisible ultraviolet light, but this radiation is changed to visible light if it excites the phosphor. Fluorescent lamps have several important advantages. By choosing the proper type of phosphor, the light from such lamps can be made to approximate the quality of daylight. In addition, the efficiency of the fluorescent lamp is high. A fluorescent tube taking 40 watts of energy produces as much light as a 150-watt incandescent bulb. Because of this illuminating power, fluorescent lamps produce less heat than incandescent bulbs for comparable light production.

That is a great definition of what a fluorescent lamp is, but does not answer the question. Does a T5HO fixture have a Mogul base lampholder or is a a T5 tube (like the T8 or T12 Tubes that we are used to)? If it does not have a mogul base lampholder 410.30 does not apply. 410.30(C)(2) only applies to electric discharge luminaires PROVIDED WITH MOGUL-BASE, SCREW SHELL LAMPHOLDERS. A T5 lamp is a fluorescent tube not a mogul base lamp.

 

[Dennis Alwon]

Where in any of this info does it say that a 30 amp circuit will allow 20 amp recep. Except #2 to 210.21(B)(3)

(3) Receptacle Ratings. Where connected to a branch circuit supplying two or more receptacles or outlets, receptacle ratings shall conform to the values listed in Table 210.21(B)(3), or where larger than 50 amperes, the receptacle rating shall not be less than the branch-circuit rating.
Exception No. 1: Receptacles for one or more cord-and-plug-connected arc welders shall be permitted to have ampere ratings not less than the minimum branch-circuit conductor ampacity permitted by 630.11(A) or (B) as applicable for arc welders.
Exception No. 2: The ampere rating of a receptacle installed for electric discharge lighting shall be permitted to be based on 410.30(C).

We all know that Table 210.21(B)(3) will not allow 20 amp recep on a 30 amp circuit. Exception 2 says to base the amp. rating of a recept. on 410.30(C)-- I do not see where C2 or C3 are even in question. I can see C1 but that just appears to give us permission to use a cord on an electric discharge lighting. It does not give us permission to use a 20 on a 30 amp circuit. Am I missing something?? The articles are the same for 2008 just different locations

410.30 Cord-Connected Lampholders and Luminaires.
(C) Electric-Discharge Luminaires.
(1) Cord-Connected Installation. A luminaire or a listed assembly shall be permitted to be cord connected if the following conditions apply:
(1) The luminaire is located directly below the outlet or busway.
(2) The flexible cord meets all the following:
a. Is visible for its entire length outside the luminaire
b. Is not subject to strain or physical damage
c. Is terminated in a grounding-type attachment plug cap or busway plug, or is a part of a listed assembly incorporating a manufactured wiring system connector in accordance with 604.6(C), or has a luminaire assembly with a strain relief and canopy having a maximum 152 mm (6 in.) long section of raceway for attachment to an outlet box above a suspended ceiling

 

[haskindm]

Dennis,
They are referring to 410.30(C)(2) which allows "receptacles and attachment plugs to be of a lower rating than the branch circuit but not less than 125% of the luminaire full load current". I maintain that this only applies to a fixture with a mogul base lampholder which a T5 fixture does not have. There is nothing in 410.30(C)(1) that would allow 20-amp receptacles on a 30-amp circuit.

 

[Dennis Alwon]

Dennis,
They are referring to 410.30(C)(2) which allows "receptacles and attachment plugs to be of a lower rating than the branch circuit but not less than 125% of the luminaire full load current". I maintain that this only applies to a fixture with a mogul base lampholder which a T5 fixture does not have. There is nothing in 410.30(C)(1) that would allow 20-amp receptacles on a 30-amp circuit.

I agree with you that's why I said 410.30(C)(2) & (3) don't appear to come into play. I figured C1 did but it does not allow this install.

C(2) Provided with mogul base, screw shell lampholders--- I also assume this is a high output fluorescent fix. Does not apply.

 

[LarryFine]

Do I win? :grin:

 

[don_resqcapt19]

With a fixture that uses a ballast, what does the lampholder have to do with the branch circuit OCPD (other than the actual code rule)? It appears to me that this is an old requirement for incandescent type fixtures and should not even apply to electric discharge fixtures.

 

[haskindm]

With a fixture that uses a ballast, what does the lampholder have to do with the branch circuit OCPD (other than the actual code rule)? It appears to me that this is an old requirement for incandescent type fixtures and should not even apply to electric discharge fixtures.

It keeps the code in agreement with itself. 210.23(B) allows a 30-amp circuit to feed a lighting circuit with "heavy-duty lampholders" (which a mogul base qualifies). No heavy-duty lampholder means no 30-amp circuit allowed for lighting. To my knowledge there is no such thing as a heavy-duty fluorescent lampholder, so there are no allowances for placing a fluorescent light on a 30-amp circuit. I believe the INTENT is to limit fluorescent lights to 20-amp circuits. If you really need to put more lights on a 20-amp circuit, you can use 277-volt fixtures, that is the only way I know about...