14/2 Cable, 20.3 Electrical Box Wiring Question
#1
09-15-17, 05:06 PM
14/2 Cable, 20.3 Electrical Box Wiring Question
I am doing basement wiring an am curious if I would overloading my electrical box.
- I have one 14/2 cable pigtailed coming in to supply power to an outlet.
- I have one 14/2 cable pigtailed going out to supply power to a switch, which will power a light.
- I have one 14/2 cable pigtailed running through the box to a seperate outlet.
Doing the math, that means I have one copper wire, six conductor wires, and one outlet.
I have read conflicting information whether or not the third pigtailed cable running through the box would count in the calculations. I would assume three 12/2 wires is not overloading, but I also dont have a problem just running to the store and getting a bigger box to make sure I am not overloading.
Thanks for the help. Sorry if my terminology is off, I just wanted to get some help prior to getting the state rough-in inspection.
- I have one 14/2 cable pigtailed coming in to supply power to an outlet.
- I have one 14/2 cable pigtailed going out to supply power to a switch, which will power a light.
- I have one 14/2 cable pigtailed running through the box to a seperate outlet.
Doing the math, that means I have one copper wire, six conductor wires, and one outlet.
I have read conflicting information whether or not the third pigtailed cable running through the box would count in the calculations. I would assume three 12/2 wires is not overloading, but I also dont have a problem just running to the store and getting a bigger box to make sure I am not overloading.
Thanks for the help. Sorry if my terminology is off, I just wanted to get some help prior to getting the state rough-in inspection.
Last edited by PJmax; 09-15-17 at 05:39 PM. Reason: corrected wire size
#2
09-15-17, 05:17 PM
Group Moderator
Welcome to the forums.
It's called box fill and box fill calculation. Every insulated wire counts as 1. All the grounds count as 1. The device counts as 2. Internal clamps count as 1.
So with three cables it would be 2+2+2+1+2+1=10 cu in
If you use a deep single gang box you will be ok. As you do your wiring.... always strive to use the deepest box possible. Installing switches and receptacles in a deep box makes the job go easier.
As an aside..... I never connect my lighting to a receptacle circuit. My receptacles could be on 12-2 or 14-2 based on the use. My lighting is always on 14-2 wiring.
Since you have a 12-2 receptacle circuit and are adding just one light.... the #12 to the light would make sense.
It's called box fill and box fill calculation. Every insulated wire counts as 1. All the grounds count as 1. The device counts as 2. Internal clamps count as 1.
So with three cables it would be 2+2+2+1+2+1=10 cu in
If you use a deep single gang box you will be ok. As you do your wiring.... always strive to use the deepest box possible. Installing switches and receptacles in a deep box makes the job go easier.
As an aside..... I never connect my lighting to a receptacle circuit. My receptacles could be on 12-2 or 14-2 based on the use. My lighting is always on 14-2 wiring.
Since you have a 12-2 receptacle circuit and are adding just one light.... the #12 to the light would make sense.
#3
09-15-17, 05:24 PM
Thank you for the welcome and the clarification.
Just curious, when you say you never connect your light to a receptacle circuit does that mean from the light to the circuit?
All of my power that I have set up thus far terminates at the light. I originally wanted to create a loop with all of my outlets and just have the lights run on different outlets, terminating at the lights.
Just curious, when you say you never connect your light to a receptacle circuit does that mean from the light to the circuit?
All of my power that I have set up thus far terminates at the light. I originally wanted to create a loop with all of my outlets and just have the lights run on different outlets, terminating at the lights.
#4
09-15-17, 05:26 PM
Group Moderator
I keep the receptacle circuits apart from the lighting circuits because if a receptacle causes a breaker trip... the lights would be out.
Personally....
I do not like using #12 wiring in a residence. It's too large for most applications and just causes excessive box fill.
Personally....
I do not like using #12 wiring in a residence. It's too large for most applications and just causes excessive box fill.
#5
09-15-17, 05:29 PM
That makes sense. So, would the recommendation be to run receptacle power and light power from a AFCI separately or run two wires from my breaker box?
***EDIT: It is 14/2 wire I am using. I don't know why I put 12/2. I am just tired. Fortunately, I am not doing any work tonight.
***EDIT: It is 14/2 wire I am using. I don't know why I put 12/2. I am just tired. Fortunately, I am not doing any work tonight.
Last edited by shook; 09-15-17 at 05:34 PM. Reason: I'm tired...long day
#6
09-15-17, 05:41 PM
Group Moderator
I changed your 12-2's to 14-2's.
It would require two circuits on two breakers. One for the lights and one for the receptacles.
You don't have to follow what I do. If you have a single light and multiple receptacles..... keep it as it is.
It would require two circuits on two breakers. One for the lights and one for the receptacles.
You don't have to follow what I do. If you have a single light and multiple receptacles..... keep it as it is.
