2020 NEC Box Fill Example Including Internal (Integral) Clamps with new Ground Fill Rules 314.16 B 2

[@kenbrown2808]

cheat mode: if you pause the video where Bill is pointing out the box size, you will see that above the brand name, the box is embossed with common wire fill ratings, and it is rated for 15 #12 "wire counts" which means 10 current carrying conductors, plus 1.25 for the grounding conductors, plus 4 for the devices, = 15.25. (I think their cheat number must already be counting the clamps; because that lines up with the volume based math)

[@SparkyChannel]

Interesting, thanks!

[@kenbrown2808]

@@SparkyChannel as an old timer from Maine taught me, 25 years ago, "you can learn a lot from a lazy man"

[@Jeff-Lawrence]

Hi Bill from Sparky Channel Wow, 2 days of code videos back to back. What a great weekend 🌞 Thanks once again for a very informative video This one was good for really drilling the box sizing concepts in. Your hard work is greatly appreciated

[@SparkyChannel]

Hi Jeff! Thanks so much!

[@MrTooTechnical]

perfect. that is why i ALWAYS get the biggest box i can find so i can always be prepared for whatever. AND i NEVER have to worry about BOX fill. thanks

[@SparkyChannel]

Right on Dave. I totally agree. It does cost a little more for a bigger box but it's well worth the extra cost.

[@wizard3z868]

@@SparkyChannel most of the time its a dime and a little extra dime doesn't matter lol

[@SparkyChannel]

@@wizard3z868 True!

[@adriandeangelis2211]

I have my doubts about how this subsection is interpreted. I believe at the end of the video, the requirements of the first and second paragraphs are incorrectly mixed. In 314.16(B)(2) - Clamp Fill - the second paragraph in the subsection is unclear to me. What type of clamps are listed for non-metallic boxes that incorporate a cable termination for the cable conductors? According to this paragraph in 314.16(B)(2), conductors can be originated in these clamps and must be counted. Moreover, these clamp assemblies shall not require a fill allowance. Still, the portion of the clamp remaining inside the box shall be subtracted from the volume of the box … without clarifying based on what volume such reduction shall be made. And by the way, reducing the box's volume is the same as adding deductions accounting for things in the box! Perhaps this subsection 314.16(B)(2) needs to be reworked. I will appreciate a clarification

[@Aepek]

Thx for the vid. Enjoy the “new code” vids you make for us. Anyone notice the Klein hybrid pliers rust a bit faster than others, or having issues with them? L8R Sparky✌🏻

[@SparkyChannel]

I've noticed that my Knipex Electrical Installation Pliers are less prone to rust than my Klein's of a similar model. Different metal compound I'm thinking. My Hybrid pliers are fine though. Thanks!

[@wim0104]

I got the yellow needle-nose hybrids, and yes. But nothing a little wd40/diesel/gas/... & weathering in can't fix: they get that nice patina any which way.

[@billdotpilot]

Sparky, if u wanted to keep the series going u could do a story on options for over filled box. You mentioned a deeper box, switching to the same size box that had the 2 screw holes on opposite diagonal corners to accept a mud ring might work and if the circuits could operate on 15 amp circuit and 14 awg wires that should work. I have run into cases where those super deep boxes hit something on the other side of the wall

[@link52j]

Hey sparky doesn't the yokes count as 2 conductors for each yoke/strap on the device's???

[@timpalmer-logstolumber1999]

I need a little clarification, since internal and integral are not the same. Integral means part of the whole and internal means inside. The code says internal not integral. Does opening the integral clamp make it internal?

[@JasonW.]

Question for non metallic boxes and clamps: In plastic boxes that do not have holes for ½ or ¾ conduit, is it NEC approved to drill out holes for those? I have a 4 gang switch box that is between two studs, and all but one wire (romex) is THHN in ENT (smurf tube) conduit. I can not find a metal box that will fit in the space between the studs, but have found a plastic one that fits perfectly. I need to drill 3 holes, 1x ½, 2x ¾, for the conduits going there, and the new romex line will use box integrated plastic clamp. This problem arised from adding a 4th 20A switch. All the switchs have pilot lights so you can tell if their circuits are energized (one of the existing is a 3 way).

[@SparkyChannel]

Interesting circuit! I would say no to drilling the holes because those boxes aren't UL listed or labeled for them.

[@JasonW.]

@@SparkyChannel all switches go to outside (3x 20A) circuits. Outside fans, heater, and now a lighting circuit.

[@--JohnDoe]

Jason, you can move a stud if you need. Or notch a stud, just not too much, I would guess no more than 1/3, most studs are just for holding up drywall. You have to get those conduits into a box that has knockouts. Or take the conduits somewhere else and change over to romex, maybe an attic or crawl space. Remember you want to always "try" to minimize splices, splices are a weak point in an electrical system.

[@wizard3z868]

chk with your ahj mine allow me to do it

[@MindKontrolleProject]

Does anyone encounter a problem with the deeper carlon boxes at 3-3/16" deep (allowing 5/8" for drywall) and stapling and routing wiring into the back of the box on a 2"x4" stud ? Risk of drywallers damaging wires?

[@CliveDrone]

Thanks Sparky. So must we deduct for all the cable clamps or just the ones used.

[@kenbrown2808]

it's one conductor count no matter how many clamps are used.

[@SparkyChannel]

@@kenbrown2808 Thanks Ken. Your answer is perfect!

[@kenbrown2808]

@@SparkyChannel I assume he missed the previous internal clamp video. It was nice and clear.

[@mikez4132]

How do the blue tabs add to fill in reality? They dont crowd the box or create heat . They dont protrude into the box like a metallic clamp with screws and a lock nut would. Just wondering what the issue really is. Too many wires would def be a problem.

[@SparkyChannel]

When they are opened they do protrude into the box, especially when you have 5 cables. I think some inspectors wouldn't count them but I think most would.

[@mikez4132]

@@SparkyChannel i agree. But it seems so minimal to even consider. Glad the channel is getting back again. Keep up the great vids!

[@SparkyChannel]

@@mikez4132 I understand. Thanks, I'm really happy the way the channel has come back. Better than ever!⚡

[@westinthe123456]

If I’m not mistaken this is the second video about integral clamps, I did comment on the last one about integral clamps. I still thing that the integral clamps shouldn’t be counted since I think the volume (with clamps) has already been included in the box writing but again I could also be wrong. Great video thank you!

[@Jeff-Lawrence]

Other manufacturers may be different but Carlin does not include the integral clamps in the box size. So you do have to subtract just as Sparky points out. I put a link in that previous video you mentioned a while back. I believe there is lack of clarity and each manufacturer should be checked to see if they include the clamps or not when sizing. But they are so small I do agree with you that they shouldn’t be included. carlonsales.com/techinfo/faqs/FAQ-ZipBoxes.pdf

[@randallthomas5207]

The clamps count, at least that is what the Carlon site says, If it has a wire in it, it counts as a clamp, You could possibly bend the clamp tab to the outside, and maki it external, but without trying it I’m not sure it would actually clamp.

[@SparkyChannel]

@@Jeff-Lawrence My thoughts exactly. My advice is to just use a bigger box though. :)

[@SparkyChannel]

@@randallthomas5207 That's an interesting thought. I think if an inspector saw the clamps bent to the outside it would horrify him. :)

[@davidkiser4758]

Is that last shot in the video from LaJolla?

[@SparkyChannel]

It looks like it doesn't it? But no, that is the "Blowhole" in Oahu, Hawaii. Lovely place!

[@Eddy63]

Good vid as always Bill ... Thnx for posting ...

[@SparkyChannel]

Thanks Eddy! Have a great day!

[@nicolaecheraru4839]

Why is it subtracting a single volume allowance on the integral cable clamp instead of adding? Allowance = giving ?

[@SparkyChannel]

You can subtract the integral clamp allowance from the cu. in. marked inside the box or you could add it together with the other volume allowances and then compare the total of the volume allowances with the cu. in. marked inside the box. It comes out the same either way. This box was overcrowded and a bigger box had to be chosen. Thanks!

[@nicolaecheraru4839]

@@SparkyChannel that makes sense now! Thank you so much, your videos are always informational! 😊

[@nicolaecheraru4839]

I am also getting ready to take my journeyman’s exam this Thursday and your videos are very helpful

[@SparkyChannel]

@@nicolaecheraru4839 Wow, fantastic! Best wishes! 😊

[@nicolaecheraru4839]

@@SparkyChannel passed my journeyman’s exam Bill!

[@wim0104]

what the hell; the printed volume in the box does not take into account the built-in clamps!? FML

[@kenbrown2808]

because the box fill of the clamp changes depending on what size wire is in it.

[@GnomesBeCool]

My thoughts exactly

[@SparkyChannel]

I thinks it's best to be safe and count them in the box fill.

[@wim0104]

@@kenbrown2808 yeah, I think it is because the code is trying too hard. If I slide a 14AWG in there, that clamp don't shrink and still occupies the whole corner. Glad I'm not an inspector! My first master taught me to rip those big clips out! #sicksadworld

[@kenbrown2808]

@@wim0104 I avoid carlon boxes because of those obnoxious things.

[@vicktorpatriot1430]

The two gang box you have is Carlon Super Blue series. Super Blue boxes have the those plastic spring like tabs for clamps even on single gang . The regular thin wall Carlon boxes don't have any cable clamps even on three and four gang boxes. Need to seal those super Blue boxes and fill with water. Then measure the volume of water and compare that to the volume molded in the box.

[@SparkyChannel]

Thanks Vicktor!

[@robertfrancis4876]

Excellent video

[@silverrod88]

Amazing information thanks so much.😎

[@SparkyChannel]

I'm glad you liked it, thanks!

[@zebiosogliani7132]

I think that the calculator engineer should make the calculation of the box filling and leave all the specifications on the plan. Those who install must dedicate themselves to installing.

[@tommycho9068]

Good video. Thank you.

[@SparkyChannel]

Thanks Tommy!

[@MarkLawry]

Very helpful. Thanks

[@SparkyChannel]

You're welcome! Thanks Mark!

[@trenvan5546]

I like the math.. but do you not just by looking at the example feel this is a bad idea? when he pulled out the receptacles I got a bit oh hell no then he did the math.. gut vindicated. if it had been switches would have required a larger box anyway.. unless you were using those wacky duplex switches still cant imagine wiring in a way I would want to be close to overfill this box