counting recessed lighting in branch circuits

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georgestolz said:
Code reference, please, Larry? :)
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I'll second that, but I'm on Larry's side.

Check out 210.24(A)(2). I think that's what he and I are thinking of.

(And now that I see Larry has agreed with George, I have this sinking feeling that there isn't some other place in the code that DOESN'T exempt lighting ...)
 
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So ... I have a question that first went through my brain when we were discussing "high efficacy lighting" in a different thread.

Most of the fixtures I see are rated some multiple of 100W, or some other value that's significantly greater than a CFL. For example, I have a table lamp that has a maximum rating of 250W and it has a 13W CFL in it. I have a bathroom fixture rated for 6 x 100W, but which I could put 6 x 11W CFLs in. Plenty of other fixtures I've installed or otherwise met over the years are likewise rather well above what would be installed using CFLs.

If I were designing a "high efficacy lighting" circuit, are there fixtures specifically rated for CFLs which have a maximum rating that's 1/10th or so what they'd be rated for "low efficacy lighting", or does one just punt and say "It's rated 100W maximum, but we're going to install an 11W CFL and that's the number we're going to use for the load calculation".

Inquiring minds and all that.
 
High efficacy lighting refers to both the luminaire and control configuration within the circuit. The luminaire is designed such that only a keyed socket will allow a high efficacy lamp (i.e. 4 pin CFL) to be installed. Additionally, the energy efficiency level may allow higher wattage lighting but with occupant sensor switching or solid state timers as does California's Title 24 energy efficiency codes. (started back in 1972)
 
I agree with RBJ. An incandescent luminaire is listed as such, and the housing and trim are rated to a maximum wattage. That wattage must be taken into consideration for load calcs for the service and branch. If someone uses a CF lamp, then goody for their electric bill but it doesn't matter to us. Incandescent lamps can still be used in them.
 
i say larry fine is correct with a max of 1440 watts on a 15 amp circuit and u r allowed 1920 watts on a 20 amp circuit with a continous load. but i always thought they consider lighting a continous load so they use 80% if u know the breaker size and 125% if they dont know the breaker size.
 
On a 20A circuit, I also use the 10 outlet rule. I usually count the center ceiling outlet in bedrooms and living rooms as 2 outlets because it could eventually hold a ceiling fan along with a 3-bulb light kit. Recessed lights usually have 65W flood lamps. So you could probably count those as 2=1. But if they are rated for 150W, you better count them as a whole outlet. If you are using fluorescent bulbs you could safely count recessed lights as 4=1. I also count the dining area ceiling outlet as one because it usually has a chandelier with multiple bulbs. 4-bulb vanity lights also count as one. Etc., etc., etc. Everybody has their own way of doing it.
 
cloudymacleod said:
i say larry fine is correct with a max of 1440 watts on a 15 amp circuit and u r allowed 1920 watts on a 20 amp circuit with a continous load. but i always thought they consider lighting a continous load so they use 80% if u know the breaker size and 125% if they dont know the breaker size.
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1440 and 1920 ARE the 80% figures. Also, 125% is the reciprocal of 80%. You don't have to do the same thing twice.

You can continuously load a circuit to 80% of its capacity, OR a continuous load requires a supply capacity of 125% of the load.
 
iwire said:
IMO there are very few continuous load branch circuits in a home.
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I've often thought about that. Lighting certainly qualifies, of course, and it could be said about HVAC systems when fired up the first time of the season, after a vacation, or after a long-term power outage.

Remember, an AC system not only has to cool the air, but must also remove the heat from the furniture, furnishings, clothing, etc., but the structure itself: floors, walls, ceilings, most framing, everything within the insulation envelope.

I still marvel at the ability of the grid to handle thousands of AC compressors simultaneously starting up after a black-out during hot weather. That's gotta be an incredible load for the first couple of seconds!
 
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