Recessed lights on one circuit

Dean1234 · 10-31-2008, 11:58 AM

I am remodeling my basement, however I am stumped on one issue. I plan for 9 Halo 4" recessed lights to run on one 15A circuit. I know the laws of 80% maximum load capacity so that would be 1440. The maximum watts per light in these are 50W, which normally I would think this is no problem (way under). However when looking at the casing of these lights (oh yeah they are IC compatible becasue they will come in contact with the insulation) it says maximum of 6 per 14awg?

Is this something that I should be concerned about? I really don't want to run seperate circuits for the lighting, are they worried the cans get too hot?

any help would be appreciated.

jbfan · 10-31-2008, 12:33 PM

I think you will find that means a total of 6 14/2 cables max for each light.
Use the max wattage for the fixture you are using to determine how many fixtures to put in.
At 450 watts, you will be fine on a 15 amp breaker.

amakarevic · 10-31-2008, 01:17 PM

i plan to have an equivalent of about a dozen recessed lights on a single 15A circuit, is that too many ?

i am using HALO H99ICT. i have seen bulbs for that going all the way down to 30W though i am using the 45W or 50W ones.

http://www.cooperlighting.com/specfi..._specsheet.pdf

Bubbagump · 10-31-2008, 01:18 PM

Yup, I just put in 20 or so of those and it is indeed 6 cables max, not 6 fixtures per circuit. Note there are 6 punch outs on the junction box.

amakarevic, 12 lights at what wattage each? 4 watts? 1000 watts?

P=VI so

In your case assuming 60 watt lamps

P= 12 * 60 = 720 total watts

720 = 110 * x
x= 6.5 amps

6.5 amps nominal use is fine for a 15 amp circuit.

For 100 watt lamps

P = 100 * 12 = 1200 total watts

1200 = 110 * x
x = 10.9 amps

10.9 amps might be pushing it as I personally like to put things at about 50% of circuit capacity.

amakarevic · 10-31-2008, 01:26 PM

Quote:

Originally Posted by Bubbagump

Yup, I just put in 20 or so of those and it is indeed 6 cables max, not 6 fixtures per circuit. Note there are 6 punch outs on the junction box.

bubba, did you put the 20 lights all on the same circuit ?

Bubbagump · 10-31-2008, 01:36 PM

Quote:

Originally Posted by amakarevic

bubba, did you put the 20 lights all on the same circuit ?

NO! There were 4 separate circuits, each with 6-8 recessed lights on each and maybe a closet light or two. On a side note, I love how the housing is like $6 and the trim is like $20. Bastages.

amakarevic · 10-31-2008, 01:40 PM

i think i will go with 45 or 50W bulbs on each light. thanks for laying out the formula for wattage vs. voltage vs. amperage, i was gonna start a separate thread to ask how it is done. but it looks simple enough.

W = A * V, correct ?

Bubbagump · 10-31-2008, 01:45 PM

Quote:

Originally Posted by amakarevic

W = A * V, correct ?

Yup. As a rule of thumb, on 110/120 AC circuits you can estimate 100 watts per amp. This gives a little padding and is easy to do in your head. So 10 100watt lamps estimates out to 10amps.... the real math puts it at 9.09 amps, but with my estimation you have a built in bit of wiggle room slightly under the actual usage. What will be interesting is if incandescents go the way of the dodo with CFLs coming in, in another 10 years we may be putting all sort of lights on a single circuit.

10-31-2008, 11:58 AM	#1
Dean1234 Newbie Join Date: Oct 2008 Posts: 5	Recessed lights on one circuit I am remodeling my basement, however I am stumped on one issue. I plan for 9 Halo 4" recessed lights to run on one 15A circuit. I know the laws of 80% maximum load capacity so that would be 1440. The maximum watts per light in these are 50W, which normally I would think this is no problem (way under). However when looking at the casing of these lights (oh yeah they are IC compatible becasue they will come in contact with the insulation) it says maximum of 6 per 14awg? Is this something that I should be concerned about? I really don't want to run seperate circuits for the lighting, are they worried the cans get too hot? any help would be appreciated.

10-31-2008, 12:33 PM	#2
jbfan Electrical Contractor Join Date: Jun 2004 Location: Newnan GA Posts: 5,080	Recessed lights on one circuit I think you will find that means a total of 6 14/2 cables max for each light. Use the max wattage for the fixture you are using to determine how many fixtures to put in. At 450 watts, you will be fine on a 15 amp breaker. __________________ Yes I am a Pirate, 200 years too late. "Jimmy Buffett"

10-31-2008, 01:17 PM	#3
amakarevic Member Join Date: Apr 2007 Posts: 2,083	Recessed lights on one circuit i plan to have an equivalent of about a dozen recessed lights on a single 15A circuit, is that too many ? i am using HALO H99ICT. i have seen bulbs for that going all the way down to 30W though i am using the 45W or 50W ones. http://www.cooperlighting.com/specfi..._specsheet.pdf Last edited by amakarevic; 10-31-2008 at 01:25 PM.

10-31-2008, 01:18 PM	#4
Bubbagump Member Join Date: Apr 2008 Posts: 104	Recessed lights on one circuit Yup, I just put in 20 or so of those and it is indeed 6 cables max, not 6 fixtures per circuit. Note there are 6 punch outs on the junction box. amakarevic, 12 lights at what wattage each? 4 watts? 1000 watts? P=VI so In your case assuming 60 watt lamps P= 12 * 60 = 720 total watts 720 = 110 * x x= 6.5 amps 6.5 amps nominal use is fine for a 15 amp circuit. For 100 watt lamps P = 100 * 12 = 1200 total watts 1200 = 110 * x x = 10.9 amps 10.9 amps might be pushing it as I personally like to put things at about 50% of circuit capacity. Last edited by Bubbagump; 10-31-2008 at 01:29 PM.

10-31-2008, 01:40 PM	#7
amakarevic Member Join Date: Apr 2007 Posts: 2,083	Recessed lights on one circuit i think i will go with 45 or 50W bulbs on each light. thanks for laying out the formula for wattage vs. voltage vs. amperage, i was gonna start a separate thread to ask how it is done. but it looks simple enough. W = A * V, correct ?

Recessed lights on one circuit