How Many Recessed Light Cans (75W) Per 15AMP Circuit? - Electrical - DIY Chatroom Home Improvement Forum

 DIY Chatroom Home Improvement Forum How many recessed light cans (75W) per 15AMP Circuit?
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10-21-2011, 11:58 AM   #1
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## How many recessed light cans (75W) per 15AMP Circuit?

I'm doing some new recessed lighting in bedrooms and am trying to gauge how many should be put on each circuit?

I understand that the good old law of 80% of maximum load capacity lands around 1440 watts on a 15 amp circuit. I'm installing IC cans that are rated up to a 75W bulb max each. I'll probably use an efficient bulb using less wattage but I know installation should be for the max amount per fixture.

So assuming fixtures are rated up to 75W each, does that in theory mean that 1440Watts divided by 75Watt fixtures = 19.2 possible fixtures per 15AMP circuit on a 14Gauge line? That sounds like way too many. I was always told that recessed lights should be kept to a max of around 8+/- max.

Can someone chime in and give what is possible in this scenario (NEC Guides), and also what they recommend as a max amount of fixtures in their own installs?

10-21-2011, 12:07 PM   #2
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Your max amount is just that, whatever your maximum allowable wattage is divided by 75. You can have that many lights or one or any number in between. Now any average sized bedroom should be able to be served by 4-6 lights but it depends on the layout.

 10-21-2011, 12:12 PM #3 Electrical Contractor     Join Date: Jun 2004 Location: Newnan GA Posts: 6,779 Rewards Points: 152 Check local code for this and you're other question. Some areas allow 10 outlets per circuit, and consider each light as an outlet. __________________ "The problem isn't that Hillary Clinton lies. We all know she lies. The problem is that her supporters don't seem to care"

 10-21-2011, 12:15 PM #4 DIY   Join Date: Oct 2011 Location: USA Posts: 34 Rewards Points: 39 Thanks for the info. So I guess that 19.2 number is right theoretically, it just sounds so high. I'm expecting between 4-6 per bedroom, so that is on average about 12-16 75W max fixtures. So i'm guessing 2 circuits will be ideal.
 10-21-2011, 01:05 PM #5 Member     Join Date: May 2009 Location: Easton MD Posts: 1,893 Rewards Points: 1,104 When did residential lights become a continuous load? 220.19(A)(1) and 220.20(A). 75%????? Where did this come from???
 The Following 2 Users Say Thank You to Code05 For This Useful Post: gregzoll (10-21-2011), Speedy Petey (10-24-2011)
10-21-2011, 01:06 PM   #6
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Quote:
 Originally Posted by iminaquagmire Your max amount is just that, whatever your maximum allowable wattage is divided by 75. You can have that many lights or one or any number in between. Now any average sized bedroom should be able to be served by 4-6 lights but it depends on the layout.

 10-21-2011, 01:16 PM #7 Licensed electrician   Join Date: Sep 2007 Location: Maryland Posts: 10,450 Rewards Points: 1,054 Perhaps what was meant was the circuit ampacity/maximum bulb per fixture rating. In this case 75 watts. __________________ Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.
10-21-2011, 01:35 PM   #8
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Quote:
 Originally Posted by Jim Port Perhaps what was meant was the circuit ampacity/maximum bulb per fixture rating. In this case 75 watts.
Did not think about that. Thanks. I thought it was a buffer on the "80%" rule so commonly misapplied.

10-21-2011, 05:27 PM   #9
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Quote:
 Originally Posted by Jim Port Perhaps what was meant was the circuit ampacity/maximum bulb per fixture rating. In this case 75 watts.
Yes, that's what I meant. Forgot about the number of outlets maximum. They don't have any amendments like that here. Best to check with your local building department to make sure if this is a permitted job.

 10-21-2011, 07:13 PM #10 Master Electrician   Join Date: Mar 2010 Location: Indiana Posts: 3,721 Rewards Points: 3,698 You may want to consider how many fixtures are installed per switch as the standard dimmers we use have a 600 watt limit. That would be a max of 8 @ 75 watts.
 10-23-2011, 11:42 PM #11 DIY   Join Date: Oct 2011 Location: USA Posts: 34 Rewards Points: 39 Checking locally, and I just looked in my box again and I have the room to fix a few more breakers so I'm going to put max 8-75W fixtures on each line, with 4 in each room on their own switch.
10-24-2011, 12:11 AM   #12
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Your 19 can lights doesn't sound off to me. Especially since most people put cfl bulbs in with a wattage around 20 watts. 19 doesn't sound too high to me at all. Just don't forget to take your other loads in to consideration. Ceiling fans, closet lights etc.

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