Lighting Load Calculations

[Dennis Alwon]

There are already LED fixtures available that you can use the LED driver input rating for the load calculation. No catch up necessary.

:happyyes:

I am fully aware of that but that was not what the op stated-- he said standard cans with led bulbs....

 

[A/A Fuel GTX]

In the sense that you present it, it is no different. In the Code sense of our responses, it is different simply because Code says so.

As a lawyer once told me, you are trying to apply logic where logic does not apply.

Then the code needs to change because in some instances, it's hypocritical and makes no sense. I'm all for safe installations but common sense seems to be fleeting........

 

[A/A Fuel GTX]

There is no "up to". They are rated 75W.
Ratings are max load.
You have to go by the rating of 75W per.
The light output "equal to" ... is moot.

So you believe every 15 Amp receptacle should be on a dedicated 15 Amp circuit?

 

[mgookin]

So you believe every 15 Amp receptacle should be on a dedicated 15 Amp circuit?

No. The code tells you what to do with that.

What's hard to understand about a fixture rated for 75W bulbs to be calculated at 75W?

If you want to pile on a whole lot of 11W fixtures on one circuit, buy fixtures rated 11W.

 

[A/A Fuel GTX]

No. The code tells you what to do with that.

What's hard to understand about a fixture rated for 75W bulbs to be calculated at 75W?

If you want to pile on a whole lot of 11W fixtures on one circuit, buy fixtures rated 11W.

So why the pick and choose with no consistency? All I'm saying is that the code needs to get up to speed with the world we live in. When 220.14(D) was drafted, LED's were a pipe dream.

 

[A/A Fuel GTX]

No. The code tells you what to do with that.

What's hard to understand about a fixture rated for 75W bulbs to be calculated at 75W?

If you want to pile on a whole lot of 11W fixtures on one circuit, buy fixtures rated 11W.

So you only put 2 of these on a 15 Amp circuit, right?

 

[Fulthrotl]

OK, so you have a 15 amp circuit, 23, 75W recessed cans on the circuit. That's 1725W total load based on the fixture rating. If the same circuit was utilized with 11W floods, that's only 253W on a circuit capable of providing 1725W. Perhaps recessed cans need to come out with similar labeling like combination dimmers have, ie incandescent, CFL and LED ratings. Heck, it won't be long and LED's will be all that are available anyway. Love the technology, let's use it to our benefit.

ok, as long as the fixture will only accept the LED element, you can use
the LED wattage.

if it's a medium base socket in the can, and the can is rated for 75 watts,
then 75 watts is what is on the calc.

this kills people in calif. on commercial lighting. they put in a can rated at
75 watts, and it blows the square footage out the door.

let's be honest here. DMF has a 4" LED with 1,100 lumens, full dimmable,
that fits in a 4SD box. things are changing, fast.

 

[Smart $]

I am fully aware of that but that was not what the op stated-- he said standard cans with led bulbs....

The point is more about this part of your statement...

Perhaps the incandescent bulbs will disappear one day and the nec will have to play catch up

...in that the NEC is already there. It doesn't have to catch up. Only how one thinks about it has to be adjusted.

 

[Smart $]

Why are you even making such a fuss over how many fixtures on a circuit?

Did you connect more than you should have and get flagged?

I don't see the difference as all that much... another home run, another breaker, no big deal.

 

[iwire]

So you only put 2 of these on a 15 Amp circuit, right?

That is not a fixture, it is a lamp holder.

 

[A/A Fuel GTX]

That is not a fixture, it is a lamp holder.

Ok, semantics..........So the 660W rating means nothing regarding the topic at hand?

 

[A/A Fuel GTX]

Why are you even making such a fuss over how many fixtures on a circuit?

Did you connect more than you should have and get flagged?

I don't see the difference as all that much... another home run, another breaker, no big deal.

No, I didn't get flagged. I'm just trying to utilize current technology at its full benefit. If one of us sheep doesn't question the shepherd once in awhile, we'll all walk off the cliff.

 

[iwire]

Ok, semantics..........

No, not semantics, the code has different rules for lamp holders.

So the 660W rating means nothing regarding the topic at hand?

No it does not have any meaning.

(D) Luminaires. An outlet supplying luminaire(s) shall be calculated based on the maximum volt-ampere rating of the equipment and lamps for which the luminaire(s) is rated.

Now if you happen to use heavy duty lamp holders like I suspect the one is in your picture this applies.

(E) Heavy-Duty Lampholders. Outlets for heavy-duty lampholders shall be calculated at a minimum of 600 volt-amperes.

So only a few can be put on a 15 amp circuit.


Smart gave you the answer, you are trying to apply logic when it is code.

If you really feel a change should be made you should put in a code change proposal now called a 'public input'.

 

[iwire]

I'm just trying to utilize current technology at its full benefit.

Actully no you are not.

You are trying to retrofit old technology installed in new construction with a new type of lamp.

If you where actully trying to use current technology you would purchase an LED fixture as Randy suggested and you could then calculate them at 11 watts or whatever the LED fixture is rated.

If one of us sheep doesn't question the shepherd once in awhile, we'll all walk off the cliff.

I would say the sheep here is the one still buying old technology and complaining the code does not keep up.

 

[Fulthrotl]

So why the pick and choose with no consistency? All I'm saying is that the code needs to get up to speed with the world we live in. When 220.14(D) was drafted, LED's were a pipe dream.

it's not inconsistent. 180 watts per outlet on a branch circuit is considered appropriate.
the marked wattage of a luminare is considered appropriate.

the "code", wether it's the NEC, LEED, or certification for Title 24, part 6 is always
going to be behind the technology, and that is going to increase as shorter time to
market cycles appear.

i saw a light fixture last week that is about to appear on the market shortly. it's LED, full digital
control, 2'x2', flat panel, and has 9 separate windows on it's face. think of a side of a
rubic's cube.

http://www.acuitybrands.com/products/rubik

that is the first generation. check out the video embedded in it.

i saw the second generation that they are working on. 16 bit color, and you can
have all the colors tumbling over and over, and the intensity on the work surface,
and the color balance on the work surface don't change. you can change the CRI
from about 20 to 95. runs on a nLight bus.

title 24 lighting compliance won't have a clue how to deal with this. not a clue.
and it'll be here before they even know how to deal with version 1.0

 

[Steven214]

I agree that 220.14(D) states you must use the maximum rating of the luminaire:

An outlet supplying luminaire(s) shall becalculated based on the maximum volt-ampere rating of the
equipment and lamps for which the luminaire(s) is rated.

However, 220.14 itself says:

... minimum load for each outlet for general-use receptacles and outlets not used for general illumination shall not be less than ...

So, can't the OP just consider the cans in question to be part of the general illumination, unless the "general illumination" is defined in a manner that conflicts with my thinking here?

Also, if he's dealing with residential, I think it is moot anyway because of:

220.14(J)
Dwelling Occupancies. In one-family, two-family, andmultifamily dwellings and in guest rooms or guest suites of
hotels and motels, the outlets specified in (J)(1), (J)(2), and
(J)(3) are included in the general lighting load calculations
of 220.12. No additional load calculations shall be required
for such outlets.
(J)(3) The lighting outlets specified in 210.70(A) and (B)

So, just like we don't have to count receptacles in residential as 180 VA, I think we don't have to sum the wattages of the individual luminaires either.

 

[Strathead]

it's not inconsistent. 180 watts per outlet on a branch circuit is considered appropriate.
the marked wattage of a luminare is considered appropriate.

Not! the 180 watts per outlet only applies to load calculation, it doesn't apply to the branch circuit. I debated on the wrong side of this one already. You can put 300 duplexes on a 15 amp circuit if you so desire.

 

[Smart $]

Not! the 180 watts per outlet only applies to load calculation, it doesn't apply to the branch circuit. I debated on the wrong side of this one already. You can put 300 duplexes on a 15 amp circuit if you so desire.

That's not exactly true.

Where you don't calculate VA per receptacle, you can put as many as you like wherever.

When you do have to calculate at 180VA for commercial or otherwise, 210.11 forces us to "distribute".

 

[Strathead]

That's not exactly true.

Where you don't calculate VA per receptacle, you can put as many as you like wherever.

When you do have to calculate at 180VA for commercial or otherwise, 210.11 forces us to "distribute".

I believe you are referring to 210.11(B) The load for commercial receptacles is not calculated on the basis of volt-amperes per square foot, so the loads don't need to be evenly applied. In a residence I think one could argue that proportioning the branch circuits by area, not the number of receptacles in a given area would be just as valid as proportioning by the number of receptacles on a circuit. Just saying. I personally, think the code should limit the number of receptacles on one circuit, but...............

 

[cyriousn]

Wouldn't the energy code prevent the use high wattage down lights from being installed in most cases? Commercially there are power density limits and on residential projects a certain percentage of fixtures need to be high efficacy which tends to limit fixture selections to LED. Also consider voltage drop and the convenience factor of having different areas on separate branch circuits. All depends on the budget of the job vs the the performance of the lighting.