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AssuredElectrical
AssuredElectrical, Master Electrician
Category: Electrical
Satisfied Customers: 4241
Experience:  Contractor-42+ Years in the ElectricalTrade
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Hello, I am wiring a series of lights. The power source feeds

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Hello, I am wiring a series of lights. The power source feeds through all the lights, and the switch is at the end of run. There is only one switch controlling all the lights (not three way). Can I do this with 12-2 wiring (yes, it's on a 20 amp breaker), or do I have to use 12-3 wire?

AssuredElectrical :

Welcome. My name is XXXXX XXXXX would be glad to assist.

AssuredElectrical :

When wiring multiple lights on a single pole switch, there are 2 options. One, you can run power to the first light, then run 12/3 cable between all the lights and at the last light, drop a 12/2 down to the switch. 2. You can run power to the first light, then 12/2 between all the lights, then you have to drop the 12/2 cable to the switch from the same first light that has the power.

AssuredElectrical :

The reason for this, is because if you run only 12/2 from light to light all the way to the switch, you will have power to the switch, but when you return power up to the lights from the switch, there will not be an extra wire to connect to the lights.

Customer:

Ok, that makes sense. Is it different if only one light (I have a schematic for that)?

Customer:

And was hoping there was a way to add multiple lights in that wiring layout?

AssuredElectrical :

One light is the same as my #2 scenario, the power and the switch are at the same box.

Customer:

ok. I'm a little limited on wiring options because I have 1/2 in conduit that limits how many wires I can pull through. I think I may have to go with the 12/3 option between lights.

AssuredElectrical :

If you have conduit, if it is complete and not just for sleeving, run THHN wire, it is much easier

AssuredElectrical :

Then you can just add wires as you need from point to point.

Customer:

ok, I have already pulled 12 gauge THHN wire through (white, black, green). Sounds like I just need to pull red between the lights.

AssuredElectrical :

Yes, that is correct

AssuredElectrical :

the red will be the wire that the light fixtures connect to from the switch

AssuredElectrical :

the black carries power all the way to the switch

Customer:

so what are all the connections from power to lights to switch?

AssuredElectrical :

Ok, first light has the power and the wires to the 2nd light, connect blacks together, connect whites together with a short pigtail and the red . The fixture connects to the whites and the red.

AssuredElectrical :

all other fixtures are the same. Blacks together, whites and reds are for the light fixture

AssuredElectrical :

do that all the way to the switch, the switch will have black and red

Customer:

so incoming, power black to first fixture black, power white to first fixture white with pigtail to red. Reds get pigtailed in at each fixture?

AssuredElectrical :

white does not connect to red

Customer:

above you said "connect blacks together, connect whites together with a short pigtail and the red"... I read that as the red gets pigtailed in with the whites

AssuredElectrical :

the red is by itself at the first light, sorry, should have been a little more detailed

AssuredElectrical :

at the other lights , there are 2 reds together

Customer:

It's Tommy, right?

AssuredElectrical :

yes, that is correct

Customer:

Let me run this back by you, just to make crystal clear.... power black in to first light, gets connected to red. That red continues to the switch and is the power in. Then, black from the switch goes back to each light and connects the blacks back to the first light. The power white coming in to first light connects to all whites through to the last light and ends there. Is that correct?

Customer:

Or the red can continue to the last light, connect to 12/2 white and go to the switch. Code the white as black/hot.

AssuredElectrical :

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Customer:

sweet jesus, a schematic; thank you Tommy

AssuredElectrical :

see if that helps

AssuredElectrical :

didnt show all the lights, but they are all the same. Power starts at the left light and carries all the way to the switch

Customer:

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Customer:

Is this correct?

AssuredElectrical :

that works also. I prefer to keep the color to color to make it easier, your way does it done also

AssuredElectrical :

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Customer:

Ok, so on your way, black passes all the way through to the switch. The red from switch then goes back and connects to all the blacks on the lights

AssuredElectrical :

correct

AssuredElectrical :

that is fairly standard and helps with troubleshooting later. we usually have red as the return on the lights

Customer:

makes sense. Thanks for your help today Tommy!

AssuredElectrical :

you are most welcome, glad to assist.

AssuredElectrical :

keep me in mind on future projects if you will

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