transman2
Senior Member
- Location
- Brooklet,Ga.
I have 10 lights pulling 1.5 amps each. 15 amps total what size circuit breaker is required. do you multiply 125% which would be a 20 amp breaker.
10 lights
- Thread starter transman2
- Start date
- Status
- Occupation
- Licensed Electrician
Are the lights going to be on continuously for three or more hours?
transman2
Senior Member
- Location
- Brooklet,Ga.
No.
- Occupation
- Licensed Electrician
15A breaker then.
ggunn
PE (Electrical), NABCEP certified
- Location
- Austin, TX, USA
- Occupation
- Consulting Electrical Engineer - Photovoltaic Systems
Wouldn't the question be if 9 or more of the lights are going to be on continuously for three or more hours?
- Occupation
- Licensed Electrician
Yes. But the heart of the question is can you run 15A of load on a 15A circuit. At least that's the way I read it.
ggunn
PE (Electrical), NABCEP certified
- Location
- Austin, TX, USA
- Occupation
- Consulting Electrical Engineer - Photovoltaic Systems
Of course, but it's Friday afternoon...
- Occupation
- Licensed Electrician
Getting all giddy thinkin' about the weekend, are ya?
Or, he's already there. :happyyes:
JasonCo
Senior Member
- Location
- Houston, Texas
If the lights are going to be on for 3 hours or more, take the total amps and multiply it by 1.25. So 15 x 1.25 = 18.75 amps. Which in this case, under a continuous load (lights are on 3 hours or more) you will need a 20 amp breaker.
If your lights are not going to be on for 3 hours or more, take the total amps of the lighting load which is 15 amps. Then go to the code book under 240.6 and find the breaker size that is closest to 15 amps but not under 15. In this case, you have a overcurrent protection device (breaker) that is exactly 15 amps. So that is your answer, 15 amp breaker.
If your lights are not going to be on for 3 hours or more, take the total amps of the lighting load which is 15 amps. Then go to the code book under 240.6 and find the breaker size that is closest to 15 amps but not under 15. In this case, you have a overcurrent protection device (breaker) that is exactly 15 amps. So that is your answer, 15 amp breaker.
ggunn
PE (Electrical), NABCEP certified
- Location
- Austin, TX, USA
- Occupation
- Consulting Electrical Engineer - Photovoltaic Systems
Covered in post #2.
mwm1752
Senior Member
- Location
- Aspen, Colo
I thouhght all lighting loads were consider contionuous
- Location
- Massachusetts
Only loads that are expected to run at maximum for three hours or more OR loads the NEC specifically tells uss to treat as continuos loads must be considered continiuos.
See article 100 for defintion of continiuos load.
We are always free to choose to treat any load as continuos if we want.
JasonCo
Senior Member
- Location
- Houston, Texas
My bad, basically just wanted to share the code reference though. So people know exactly what breaker (OCPD) to buy.
- Location
- Massachusetts
No worries, welcome to the forum.
What code section would you say applies in this case?
JasonCo
Senior Member
- Location
- Houston, Texas
No worries, welcome to the forum.
What code section would you say applies in this case?
Thanks, really enjoying the forum! Going to turn me into a badass electrician haha
Code reference would be:
Article 240: Overcurrent Protection.
240.6(A) is for Standard Amp Ratings for fuses and Circuit Breakers.
210.20(A) Continuous and Noncontinuous Loads. Lets you know when to multiply by 1.25 (125%) of the load.
mwm1752
Senior Member
- Location
- Aspen, Colo
Arbitrary true to form --:slaphead:
- Location
- Massachusetts
If you hang here you will learn more than you can imagine and because you get to pick and choose which subjects you work on it is a lot more fun than a class.
Its been a lot of years since I was a newbie on these forums but many of the members I learned a ton from are still here. None of us where born with what we know and there is always something more to learn if you want.
:thumbsup:
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