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Old 08-30-2013, 10:46 PM   #1
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Multiple lights/switches on single circuit


Remodeling one level of a split. Gutted area and reconfigured the rooms. As a result, all of this existing wiring has been removed. Going to wire with fresh runs from newer breaker box. Looking for some advice on running wire in an efficient and correct manner on four of the lights. In the pictured diagram, I have four lights and switches labeled as L1, S1, etc…. The lights in the small interior room are for the powder room and will be on a different circuit due to a vent fan and load I wanted to put on the other lights. For the switch boxes, I am using 22.5 cubic inch boxes and for the ceiling fans I am using 21.5 cubic inch boxes (part of a heavy duty ceiling fan mounting system). L1 is an existing outside light that cannot be a junction. L4 is a closet light that can have a large box if needed. The power will come in from with 14 gauge wire where it is labeled “Power Enters Here”. Is it better to have the junctions in the switch boxes or the light fixture boxes? Does it matter to NEC assuming the junction points have capacity to handle the number of wires? Based on my box sizes, is there enough room for the number of wires? Also, what is the best path to run on a single circuit with 14 gauge wire? For the ceiling fans, I am not installing separate switches for the light and fan. They will be controlled by one switch.
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Old 08-31-2013, 02:36 AM   #2
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Multiple lights/switches on single circuit


I would junction in the switch if possible for easier access. Code says no more than four wires in a box and depending on wire gauge, fittings, device, and how many conductors, that will tell you your cubic inch size for box. So 4 14/2 lines with device would be 22 cubic inches

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Old 08-31-2013, 04:59 AM   #3
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Multiple lights/switches on single circuit


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Originally Posted by romex1220 View Post
I would junction in the switch if possible for easier access. Code says no more than four wires in a box and depending on wire gauge, fittings, device, and how many conductors, that will tell you your cubic inch size for box. So 4 14/2 lines with device would be 22 cubic inches

You are making stuff up again. There is no limit as long as the box is large enough. Your example is correct for a single gang 22 cu in box.

OP: Run 3 wire cable from the switch to the fans. No reason not to since you are doing a rewire and most people like separate switches for light and fan (even if you don't).
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Old 08-31-2013, 07:02 AM   #4
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Multiple lights/switches on single circuit


Quote:
Originally Posted by romex1220 View Post
I would junction in the switch if possible for easier access. Code says no more than four wires in a box and depending on wire gauge, fittings, device, and how many conductors, that will tell you your cubic inch size for box. So 4 14/2 lines with device would be 22 cubic inches
As RJ said, your math is correct. However, there is no code rule that you can cite to back up your quote.

Also, you used the word wire when you were talking about cables. Please try to give out correct information using correct terminology.
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Old 08-31-2013, 12:52 PM   #5
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Multiple lights/switches on single circuit


Thanks for the advice and suggestion regarding using the 14/3 on the ceiling fans. I looked at trying to go the route the power via the switches, however, I would have problems bringing that many cables to S2 and S3 due to the HVAC, plumbing vent pipe, and framing. I can bring one wire down to each one (S2 and S3). How does this route sound?

Source to S1 > L2 > L3 > S4

I was going to run 14/3 from L2 > S2 and L3 >S3 and 14/2 from S1 to L 1 and S4 to L4.

My ceiling boxes for L2 and L3 are 21.5 cubic inches. So if I use the 14/3 it looks like I will have to add an extension ring to my ceiling boxes as I calculate 22 cubic inch requirement based on 2 for power in, 2 for power out, 1 for ground, 3 for 14/3 to switch and 3 for the device, which is 11 * 2 (inches for 14 awg) equals 22 cubic inch requirement. Does that sound right? Looks like the requirement for the S1 box would be 18.
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Old 08-31-2013, 02:20 PM   #6
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Multiple lights/switches on single circuit


Fixture wires are not counted towards box fill.
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Old 08-31-2013, 06:25 PM   #7
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Multiple lights/switches on single circuit


I suggested using 3 wire cable(14-3 or 12-3) between the switches and fans so you can have separate switches for the fan and light. If you bring power feed to the fan, you cannot as you will need a neutral, hot and switched hot in the cable. Find a way to bring power to the switch boxes.

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