Multiple Lights on the same Circuit

[bamava05]

We are installing multiple lights within the on one circuit. These lights are in close proximity to each other but will be controlled by different switches..example being, the overhead garage lights and the outside garage lights will be on the same circuit but will be controlled by different switches.
My question is how should these be wired to meet NEC code (2014 NEC)? Will it require 12-3 or can it be done with 12-2,,again this will need to meet code.
Any help is much appreciated.

 

[ddawg16]

You can put 1000 lights and 1000 switches on a single circuit if you want.....as long as the wire is matched to the breaker....

20A = 12Awg wire
15A = 14Awg wire

If you want to use 12-3, that is fine, but it won't change the breaker unless you are thinking a MWB.

What kind of lights are you going to use? Have you added up the total wattage?

 

[ddurrett896]

You only need the 3rd wire if the same lights are controlled by different switches.

 

[bamava05]

the wattage is minimal, its on a 20 am circuit. The lights are completely different areas (outside lights, overhead garage lights) so they will be controlled by separate switches. at separate times.

 

[Falcon67]

I'd consider pulling incoming power to a series of 4x4 boxes. From each box, you run your light power and a switch leg. Mark the box lids with the breaker number or other designation and a note about which box serves what. Depending on how many runs in and out, you might get it done in a single box. Having done that in the past, it's a PITA if you need to get back in that box LOL. Better to break them out. 12-2 is more than plenty, especially if later you decide one of the boxes is in a prime location to tap for an outlet.

 

[sberry]

Yes, you can use 3 conductor, can switch or supply 2 lights.

 

[theoldwizard1]

I think it is NEC 2014 that requires a neutral in every box whether it is used or not.

For example, if power was feed to a 4 space box that had 4 switches to 4 different (sets) of lights, you would have to run 14/3 to each light fixture even though the neutral is not used. Power to/from the light fixture would be on black/red and white would be the neutral, "reserved for future use".

I don't know what the "grandfather" rules are, but if it is a new garage, I am sure this would be required.

 

[Stuart in MN]

As said above you can have multiple light circuits running off a single breaker, that's not a problem. But, the total draw on the circuit has to be within the limits of that breaker. You haven't the number of lights or how many watts they will consume...

 

[TRWham]

If the switches are in the same box, just pigtail the homerun to both, then run from the appropriate switch to each set of lights. For lights I would run 14 gage on a 15 A branch circuit unless they were especially large.

 

[TRWham]

You can put 1000 lights and 1000 switches on a single circuit if you want.....as long as the wire is matched to the breaker....
...?

Perhaps if they are very small, but in a dwelling each lighting circuit is limited to no more than 20 A so there is a practical limit.

 

[teamextreme]

He is asking about the requirement for a neutral in each switch box, nothing about loading the circuit or anything else. You don't necessarily need 12-3 (or 14-3), you just need to have a neutral present in the switch box. So if the power feed hits the switch box first you're fine. The new rule requires you to run 3 conductor wire when you are running power to the fixture box first, then using a switch leg down to the switch. The run from the fixture box to the switch would need the 3-wire. In the past you would use 2 conductors for hot and return, no neutral. You can't do that anymore without running the neutral with it, hence the 3 conductor requirement.

 

[bamava05]

Thanks for all the great replies. Let me put a little more detail in here.
The circuits are all 20amp.. the amount of lighting im using will be fine.
I have actually already wired 12/2 to all the light fixture boxes before I even thought about possibly needing 12/3.
I need to meet code and would like to do it without taking all the 12/2 down and replacing with 12/3. This is new construction so not a a massive problem to replace it but would rather not.
If I can meet the 2014 code by leaving the 12/2 wired to the light fixture boxes that would achieve my goal.
Again, thanks for the help.

 

[PCustoms]

Thanks for all the great replies. Let me put a little more detail in here.
The circuits are all 20amp.. the amount of lighting im using will be fine.
I have actually already wired 12/2 to all the light fixture boxes before I even thought about possibly needing 12/3.
I need to meet code and would like to do it without taking all the 12/2 down and replacing with 12/3. This is new construction so not a a massive problem to replace it but would rather not.
If I can meet the 2014 code by leaving the 12/2 wired to the light fixture boxes that would achieve my goal.
Again, thanks for the help.

Do you have feed-->switch-->fixture? 12/2 is OK.

If you have feed-->fixture-->switch you will need to run 12/3 from the fixture down to the switch. Black and red become the switch loop, white (neutral) gets nutted in the box, and you meet code.

 

[bamava05]

we only have the 12/2 running from the fixture to the switch box, roughed in only. have not wired the feed to the switch box yet.
so sounds like i may be okay.

 

[teamextreme]

we only have the 12/2 running from the fixture to the switch box, roughed in only. have not wired the feed to the switch box yet.
so sounds like i may be okay.

As long as you run the incoming power feed to the switch box first, then you're ok.

 

[bamava05]

great! do we use 12/2 or 12/3 from power feed to the switch boxes?

 

[bamava05]

looks like 12/2 from feed to switch box, then 12/3 from one switch box to the other.. the light fixtures will be 12/2 running to the switch box.

 

[theoldwizard1]

He is asking about the requirement for a neutral in each switch box, nothing about loading the circuit or anything else. You don't necessarily need 12-3 (or 14-3), you just need to have a neutral present in the switch box. So if the power feed hits the switch box first you're fine. The new rule requires you to run 3 conductor wire when you are running power to the fixture box first, then using a switch leg down to the switch.

I am not a pro (nor an NEC lawyer), but my understanding was ALL boxes required a neutral "for future use".

 

[theoldwizard1]

great! do we use 12/2 or 12/3 from power feed to the switch boxes?

Someone smarter than me will have to quote the NEC section.

I have seen more and more videos where when 14/2 or 12/2 was used for the switched leg, the white was marked with red. Is that a code thing now or just a reminder for rookies ?

 

[teamextreme]

I am not a pro (nor an NEC lawyer), but my understanding was ALL boxes required a neutral "for future use".

In the context of this thread, we are discussing 2 boxes, the fixture box and the switch box. The fixture box obviously is going to have a neutral or the light won't even work. So the only box left to discuss is the switch box, which is what we are saying needs the neutral. What other box are you referring to? And the code text discusses switch boxes specifically.

Someone smarter than me will have to quote the NEC section.

I have seen more and more videos where when 14/2 or 12/2 was used for the switched leg, the white was marked with red. Is that a code thing now or just a reminder for rookies ?

Using **/2 and marking the neutral is the old way of doing it that has been disallowed. When it was allowed, you were required to mark the neutral and use it for the hot feed to the switch, not the switched leg back to the fixture. This is the practice we are discussing as not being allowed anymore, and you have to run **/3 to the switch box in order to supply a neutral. This is of course assuming you are not running power to the switch box first, which would provide the required neutral in doing so.