Thanks for the great video. Box fill is often overlooked by homeowners doing their own electrical. I know I've overlooked it in the past. The code and table references will help me calculate all neccesary allowances on future projects.
I really needed this! Best explanation I've seen. I've read the NEC article, but seeing it explained by example really clarified things for me. THANKS!
Love these little code book explanations and love your back yard pond especially the chimes 🤣😅😂 Thx as always for posting as they are very educational ...
Good to know, Thanks! As a DIYer doing my kitchen this is important from a practical point of a view. I was installing some 12 ga Armored Cable and had a tough time in any box that had more than a single cable / device. Even if it was technically within spec. First, the 12 ga conductors are much stiffer than the 14ga i had been working with previously. Internal clamps that come with some boxes are very wasteful, so i switched to the external clamp where possible . I also removed unused internal clamps ( if there's 2 cables, put them on the same side (top or bottom) and remove the unused clamp) I also noticed that the internal Metal Cable clamps can damage conductors - they protect it where it enters through the hole; but a conductor thats folded back and pushed in can contact a sharper edge. Big boxes and Mudrings help, especially with GFCI receptacles
While adding a new cable into an existing one or two gang box sometimes the only way to not go over the box capacity is to use the receptacle to join two sets of wires rather then adding two splices .Best practice is to use deep boxes everywhere. Good luck attempting to get the extra deep receptacles with USB charging outlets into a 2.5" deep wall case that contains two cables. Will need a shoe horn rubber mallet & an extension box.
funny thing was when I left brand X, who insisted on using the shallowest box the conductor count would allow (resulting in having to change out at least two boxes during the wiring process of every house, at the cost of time) I found out that full depth boxes were a cent cheaper than shallow boxes.
I prefer to do my math in the other direction. take the box volume (42 and change cubic inches) and divide by my conductor volume (2.25) which lets me know I can have 18 conductor counts in the box. another thing an inspector pointed out ages ago: since I'd laid the box in so neatly that there was clearly room for any size device; there was no need for him to count conductors.
Yes you get a conductor count up front, but you still have to do Bill’s math direction to an extent to have your answer. While you do not have to multiple your conductor count, you did by dividing. Sorta like 5+5=10, 2+8=10, 3+7=10, 2*5=10; get the ideal?
@coypatton3160 yes, it is still math, it's just a matter of preference. If you are aware of box capacity in conductors, you can easily see if you're going to have to think about box fill before you commit.
As of the 2023 code that will be a flawed method, as it doesn't take into account for any extra EGCs above 4. Which if you had 4 extra EGCs, you would have to allow for a whole extra conductor. 🤔
@@chaser9363 OMG, you mean because the number of grounding conductors makes the grounding conductor count as 2 conductor counts, I can no longer calculate the number of conductor counts allowed in my box, rather than calculate how many cubic inches my conductors add up to, and then find out if that is bigger than my box? does that mean quality box manufacturers will also stop staming the box with how many conductor counts it can accommodate based on the AWG of the conductors; because the grounding conductors might count as two conductors?
Hey Bill. Great coverage on this topic 👍 sooo many people don’t know how to properly apply the math on this subject. Especially when there’s different size wires to contend with. Great explanation Bill
I've read the article several times, but I was a bit confused. The explanation with a visual aide really helped me. Now I know how to correct the jboxes in my attic. When I rewired my 1950 house I removed all the cotton wrapped/no ground wiring, and replaced it with 14-2 & 12-2 Romex. NOW I know how I can remedy my overfilling with a mud ring.
@@im2yys4u81 boy over my time as an electrician I came across some of these old houses and it’s amazing how the electric system survived. Back in that day you were lucky if you had an electrician do the job. Plus there was hardly any NEC to go by. What was your biggest challenge?
@@anthonyelectric6045 My journey started when I first bought my house in 2018. I went to replace an old light fixture, and when I removed it the only thing poking through the ceiling was a bare wire. That led to my going up in the attic and finding jboxes filled with melted wires and branch circuits with the insulation falling off. Took me a bit of time, but I eventually rewired the entire house with 14-2 Romex for my lights, and 12-2 for my wall receptacles. I added several GFCI's. 4 in my kitchen (one on each end of my kitchen counter and one in each wall), one in my bathroom, and one dedicated GFCI in each room. For safety sake I divided the lighting and receptacles into three zones, with each zone having it's own home run on the appropriate sized breaker. Prior to that my old glass fused panel was filled with 30 amp breakers, which I KNEW wasn't right. My biggest challenge has been the one Sparky just covered. Several of my jboxes are overfilled, but I didn't know that because I assumed that whoever wired the house knew what they were doing. As of now, I've replaced all the wiring, and this past week I dove in and replaced my old fuse panel with a Square D Homeline. The truth is it was a cakewalk. I ended up having to run a 4awg ground from my main disconnect to the sub because when they added the 200 amp main they only ran 3 wires (two hots and a bare stranded neutral) to my sub, and they did not separate the neutrals and the grounds. I had added a ground bar to the sub, but I was unaware that there needed to be a ground wire from the main to the sub. I ended up taping the bare stranded neutral with white phasing tape, and ran a green 4awg from the main to the sub. Best I know I am now 100% code compliant, with the exception that the jboxes in my attic are overfilled, which I'll remedy TODAY by adding a mud ring and a cover. ALL my connections were made with Wagos, and I did install green grounding pigtails inside my jboxes. To give credit where it is due, I am NOT an electrician, and EVERYTHING I did I learned on Sparky's channel. My real estate agent informs me that my improvements increased the value of my home by $15-$20,000, but my biggest reward is job satisfaction, and knowing my house isn't going to have an electrical fire.
Just curious, if this setup was meant to be covered with drywall, then would you need to have a neutral in the box with the single 3 way switch? Awesome info though!
The NEC code changed a cycle or 2 back (sorry, can't remember exactly when and my code books are at the office) - but you now must run a neutral wire even if not connected to each 3 way switch. Reason: the newer "Ring" or other smart switches require a neutral in order to work correctly, so we're now required to run a neutral out even if it's just wirenutted off.
Hi Sparky, what's your position on non-metalic boxes with integral clamps like the plastic Carlon boxes? Should those have a volume allowance taken? I figure it's already been taken into account in the stamped/listed volume of the box, but the code still doesn't seem clear on that.
If there were no other receptacles on this circuit then that single receptacle (wired to a 20 amp circuit) must be a 20 amp receptacle according to code.
They reference the code I discuss in this video: How Long do Wires Need to be in 2023? NEC 2023 300.14 and 314.17(B)(2): th-cam.com/video/2z61qTfkXZo/w-d-xo.html
you might want to clarify what you mean by a "switch loop" what it means to me is when the power comes into the light, and a single cable comes from the light to the switch. the only time that is necessary is if your switch is designed in such a way that there is only enough wiring space in the box for the one cable.
@@wolfworrier3169 in the us, most electricians run power to the switch location and one cable to the light like bill has it in this video. Some run one cirxuit for both lights and receptacles, bit i prefer to run a 15 amp circuit just for lights, and a 20 amp circuit just for receptacles.
I think the NEC people are electricians that feel like they need more money. I am NOT rewiring my house. And if I ever MUST, because of a failure, I am drilling a lot of holes in my floor for conduit pipe. I am NOT opening walls. I like the industrial look anyway. They go a little too far sometimes.
Thanks for the great video. Box fill is often overlooked by homeowners doing their own electrical. I know I've overlooked it in the past. The code and table references will help me calculate all neccesary allowances on future projects.
Thanks Gregory!
Always a pleasure Bill, always a pleasure
Cheers✌🏻
Good to hear from you! Cheers from San Diego!
I really needed this! Best explanation I've seen. I've read the NEC article, but seeing it explained by example really clarified things for me. THANKS!
Fantastic! Thanks.
Love watching you explain the code Sparky.
Sounds good, thanks!
Always enjoy your code interpretation explanation Sparky. Another great video.
Thanks Gary!
Thanks for this! I'm going to add it to my NEC class rotation.
Excellent! It sounds like you're doing a great job of teaching!
Thanks Sparky!
No problem, thanks!
Great info. Sparky. Thanks.
You bet!
Love these little code book explanations and love your back yard pond especially the chimes 🤣😅😂 Thx as always for posting as they are very educational ...
Thanks Eddy! That's the San Diego Botanical Gardens. It's very relaxing.
Good to know, Thanks!
As a DIYer doing my kitchen this is important from a practical point of a view. I was installing some 12 ga Armored Cable and had a tough time in any box that had more than a single cable / device. Even if it was technically within spec.
First, the 12 ga conductors are much stiffer than the 14ga i had been working with previously.
Internal clamps that come with some boxes are very wasteful, so i switched to the external clamp where possible .
I also removed unused internal clamps ( if there's 2 cables, put them on the same side (top or bottom) and remove the unused clamp)
I also noticed that the internal Metal Cable clamps can damage conductors - they protect it where it enters through the hole; but a conductor thats folded back and pushed in can contact a sharper edge.
Big boxes and Mudrings help, especially with GFCI receptacles
Excellent points, thanks!
While adding a new cable into an existing one or two gang box sometimes the only way to not go over the box capacity is to use the receptacle to join two sets of wires rather then adding two splices .Best practice is to use deep boxes everywhere. Good luck attempting to get the extra deep receptacles with USB charging outlets into a 2.5" deep wall case that contains two cables. Will need a shoe horn rubber mallet & an extension box.
funny thing was when I left brand X, who insisted on using the shallowest box the conductor count would allow (resulting in having to change out at least two boxes during the wiring process of every house, at the cost of time) I found out that full depth boxes were a cent cheaper than shallow boxes.
Great vid
Thanks Dave!
Bill, you need to get your content approved for continuing education credits, would love to be able to watch your vids towards my PE renewals!
Great idea, thanks!
I prefer to do my math in the other direction. take the box volume (42 and change cubic inches) and divide by my conductor volume (2.25) which lets me know I can have 18 conductor counts in the box. another thing an inspector pointed out ages ago: since I'd laid the box in so neatly that there was clearly room for any size device; there was no need for him to count conductors.
Good tip, thanks!
Yes you get a conductor count up front, but you still have to do Bill’s math direction to an extent to have your answer. While you do not have to multiple your conductor count, you did by dividing.
Sorta like 5+5=10, 2+8=10, 3+7=10, 2*5=10; get the ideal?
@coypatton3160 yes, it is still math, it's just a matter of preference. If you are aware of box capacity in conductors, you can easily see if you're going to have to think about box fill before you commit.
As of the 2023 code that will be a flawed method, as it doesn't take into account for any extra EGCs above 4. Which if you had 4 extra EGCs, you would have to allow for a whole extra conductor. 🤔
@@chaser9363 OMG, you mean because the number of grounding conductors makes the grounding conductor count as 2 conductor counts, I can no longer calculate the number of conductor counts allowed in my box, rather than calculate how many cubic inches my conductors add up to, and then find out if that is bigger than my box? does that mean quality box manufacturers will also stop staming the box with how many conductor counts it can accommodate based on the AWG of the conductors; because the grounding conductors might count as two conductors?
Hey Bill. Great coverage on this topic 👍 sooo many people don’t know how to properly apply the math on this subject. Especially when there’s different size wires to contend with. Great explanation Bill
I've read the article several times, but I was a bit confused. The explanation with a visual aide really helped me. Now I know how to correct the jboxes in my attic. When I rewired my 1950 house I removed all the cotton wrapped/no ground wiring, and replaced it with 14-2 & 12-2 Romex. NOW I know how I can remedy my overfilling with a mud ring.
@@im2yys4u81 boy over my time as an electrician I came across some of these old houses and it’s amazing how the electric system survived. Back in that day you were lucky if you had an electrician do the job. Plus there was hardly any NEC to go by. What was your biggest challenge?
Thanks so much!
@@im2yys4u81 Excellent!
@@anthonyelectric6045 My journey started when I first bought my house in 2018. I went to replace an old light fixture, and when I removed it the only thing poking through the ceiling was a bare wire. That led to my going up in the attic and finding jboxes filled with melted wires and branch circuits with the insulation falling off. Took me a bit of time, but I eventually rewired the entire house with 14-2 Romex for my lights, and 12-2 for my wall receptacles. I added several GFCI's. 4 in my kitchen (one on each end of my kitchen counter and one in each wall), one in my bathroom, and one dedicated GFCI in each room. For safety sake I divided the lighting and receptacles into three zones, with each zone having it's own home run on the appropriate sized breaker. Prior to that my old glass fused panel was filled with 30 amp breakers, which I KNEW wasn't right. My biggest challenge has been the one Sparky just covered. Several of my jboxes are overfilled, but I didn't know that because I assumed that whoever wired the house knew what they were doing. As of now, I've replaced all the wiring, and this past week I dove in and replaced my old fuse panel with a Square D Homeline. The truth is it was a cakewalk. I ended up having to run a 4awg ground from my main disconnect to the sub because when they added the 200 amp main they only ran 3 wires (two hots and a bare stranded neutral) to my sub, and they did not separate the neutrals and the grounds. I had added a ground bar to the sub, but I was unaware that there needed to be a ground wire from the main to the sub. I ended up taping the bare stranded neutral with white phasing tape, and ran a green 4awg from the main to the sub. Best I know I am now 100% code compliant, with the exception that the jboxes in my attic are overfilled, which I'll remedy TODAY by adding a mud ring and a cover. ALL my connections were made with Wagos, and I did install green grounding pigtails inside my jboxes. To give credit where it is due, I am NOT an electrician, and EVERYTHING I did I learned on Sparky's channel. My real estate agent informs me that my improvements increased the value of my home by $15-$20,000, but my biggest reward is job satisfaction, and knowing my house isn't going to have an electrical fire.
Just curious, if this setup was meant to be covered with drywall, then would you need to have a neutral in the box with the single 3 way switch?
Awesome info though!
The NEC code changed a cycle or 2 back (sorry, can't remember exactly when and my code books are at the office) - but you now must run a neutral wire even if not connected to each 3 way switch. Reason: the newer "Ring" or other smart switches require a neutral in order to work correctly, so we're now required to run a neutral out even if it's just wirenutted off.
Hi Sparky, what's your position on non-metalic boxes with integral clamps like the plastic Carlon boxes? Should those have a volume allowance taken?
I figure it's already been taken into account in the stamped/listed volume of the box, but the code still doesn't seem clear on that.
Integral clamps count as one allowance no matter how many there actually are
Good morning Sparky, What would cause lights to flicker in some areas of my house and not others. Thank you.
Loose wires can do it. Also, too much voltage drop can do it.
@@SparkyChannel Thank you Sparky.
If there were no other receptacles on this circuit then that single receptacle (wired to a 20 amp circuit) must be a 20 amp receptacle according to code.
That's not a 20 amp receptacle. If it was the grounded conductor slot would have like a sideways "T" configuration.
Is the conductor volume allowance 314.16(b)(1) based on 6" of conductor length?
They reference the code I discuss in this video: How Long do Wires Need to be in 2023? NEC 2023 300.14 and 314.17(B)(2): th-cam.com/video/2z61qTfkXZo/w-d-xo.html
How long have devices counted as 2 (two) conductors?
Quite a while, I'm not exactly sure though.
How is 2 devices 9 cubic inches ?
One device is double fill of the wire. 2.25 x2 is 4.5. Two devices is 4.5 x2. 9 cubic inches.
Is a switch loop necessary, we use it in Jamaica but I hate it
you might want to clarify what you mean by a "switch loop" what it means to me is when the power comes into the light, and a single cable comes from the light to the switch. the only time that is necessary is if your switch is designed in such a way that there is only enough wiring space in the box for the one cable.
Yes it comes in at the light
@@wolfworrier3169 in the us, most electricians run power to the switch location and one cable to the light like bill has it in this video. Some run one cirxuit for both lights and receptacles, bit i prefer to run a 15 amp circuit just for lights, and a 20 amp circuit just for receptacles.
@@kenbrown2808 I agree 100%, that way you can kill the power to the receptacle circuit and work on it with the lights on!
@@jimmac1185 or turn off the light circuit to work on it and plug in a worklight.
I think the NEC people are electricians that feel like they need more money. I am NOT rewiring my house. And if I ever MUST, because of a failure, I am drilling a lot of holes in my floor for conduit pipe. I am NOT opening walls. I like the industrial look anyway. They go a little too far sometimes.
Like conduit in unfinished section of my basement & garage but no where else Good luck selling a house with conduit in every room.