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View Full Version : How many can lights can I put on a single 15 or 20 amp ciricut?


obrbob
May 6, 2008, 05:49 PM
I am remodeling my basement and am putting in drywall to increase the height to a full ceiling from a drop ceiling. I want to wire all of the lights on one line, but I don't know how man I can safely put on one breaker. Is there a formula out there I can use? I can replace the breaker to 20 amp, it's 15 amp now.

Thanks

mr500
May 6, 2008, 08:55 PM
How many watts are the lights you are using? Not really a limit I don't think

Add up the wattage and divide by the amt power coming in. In this case 120 V. That will give you the amps draw on that line.


5 lights at 60 w a PC. 30/120 .25amp. I think that's correct. If not someone will chime in and correct me! ALSO KEEP IN MIND you can't use more than 80% of the breaker rating, or about 12 amps for a 15 amp breaker.


DON'T replace the 15 amp breaker unless you know that you have 12/2 wire. If its 15amp breaker probably 14-2 and not 12/2. Use that. You will be OK.. 14/2 is not rated to hold 20amps. But still with a 15amp and 14/2 you are OK

Mike

Washington1
May 7, 2008, 03:09 PM
An outlet supplying luminaires (Fixtures) shall be calculated based on the max voltage amp rating of the equipment, and lamps for which the fixture is rated.

SO: If you have a can light with a max VA rating of 75 , then you would use 75 watts in your calculation.

15 amp circuit----So: E(I)=P 15A(120V)=1800 watts So a 15A circuit can have up to 1800watts installed (non-continuous load)
I want get into continuous loads, because we are dealing with residentiaL. If someone wants to argue this, then look at the definition of continuous load, then see NEC Table 220.12

So lets say you want to install some can lights on a 15A circuit with a max load of 75 watts per recess can. How many recess can lights can you install on this 15A circuit:

1800/75=24 can lights

Q: Would I put that many can lights on a 15A circuit. Nope! Personally, I would't install over 15 can lights--but that's just me.