2020 National Electrical Code (NEC) changes to Articles 320 and 330. Types AC and MC cable.
2024 ж. 16 Мам.
29 443 Рет қаралды
This video covers the changes in the 2020 NEC to Articles 320 and 330 for MC and AC cable.
This video covers the changes in the 2020 NEC to Articles 320 and 330 for MC and AC cable.
Thanks Ryan for sharing your knwoledge, great video, and great answers to the questions. You always know where to watch out. Very nice.
Thank you Ryan. Clear, concise, informative, easy to follow and understand. You should consider taking this on the road
Best 14 minutes well spent of the day, I understood every bit of it! Thank you!
Thanks!!
Ryan, I'm enjoying your instruction/interpretation of the chosen code sections very much. I'm long since retired but instructed code changes for many years in upstate New York and was a technical subcommittee member for the international family of codes when NYS first adopted the family of building codes. I worked on the electrical codes. I retired due to health reasons and very much miss my work. You're doing a wonderful job and I just wanted to note special recognition to your channel and superb efforts. Keep up the wonderful work. Sincerely, Fred Warner
Thanks so much, I really appreciate that!
Thanks for the update on the changes most of the times we find out when inspector write us a correction who buys a nec book every 2 years and read it to be up to the code
Every 3 years. Dukes of hazard philly uses the 2017 NEC for 1 & 2 family dwellings and the 2014.NEC for.every thing else.
So, who buys a nec book every two years and reads it to be up to code??? Well, how about anyone who values his work?? Or has PRIDE in a job done well AND CORRECTLY? Or values the health and safety of his clients/customers? Care and pride in your work. Why can’t it be everybody’s job #1????
This is a really great channel. Facts are presented with the section of code identified.
Thanks!
I did this last summer and I read the rule as the person who pointed out the misunderstanding. The guard rails and strips took a long time but I saw the value of that. Unfortunately the previous installers still had unprotected cable hanging around
Hi boss, from philippines here watching ur video, and also a electrical practitioner. Keep up
Thanks!
It makes sense. My attic is full of wires going every which way. Throw a piece or two of 2x8' plywood, and it's bound to be over some NM cable, which will then get stepped on periodically. The bigger problem is the insulation being added after the fact. No one is checking the electrical when insulation is added because of inadequate insulation in older houses, let alone the big bundle of cables running adjacent to each other.
Ooops should say my rant below is what I'm thinking of right now. Not specific to the subject of this vid. Sorry for venting. Love your passion and am always interested.
Thank you for your videos.
Greetings: I understand the the rule exactly proper, as it is written and intended. Perhaps the confusion is in the reading comprehension. Remember... RIF. Thx 4 the share. Keep up the good work.
Excellent, clear information
Next question is “how do you make the attic ladder temporary?” Wing nuts and a placard?
Gravity takes care of that. It actually costs more and takes more effort to make them permanent.
Talking about attics, FYI, my bathroom in my 1957 home had a single switch serving a cabinet light & a ceiling light with an exhaust fan. The main junction was located in the cabinet light ie. wall light - meaning the ceiling light & fan & a single switch all tied back to the junction box for the wall light. I wanted to install a GFI outlet, & have individual switches for the ceiling light, the ceiling fan & the cabinet light. A hardware consultant suggested I install an additional junction box in my attic space. My attic had no fixed means of access (in other words, getting the stepladder from the garage was my means of access). I told the electrician to go ahead & install an additional junction box in the attic to tie together the additional circuits & switches. The reason being: the junction box on the wall light was too full to tie in the new GFI as well as all the additional switches. To my surprise the electrician fastened the new j-box to the top chord of the ceiling joists. It did not look right (A 4" box sitting center on top of a 1 1/2" joist & with no cover plate) I'm not an electrician but he is. I didn't take out a permit for this job, & nor did the electrician. I was only adding an outlet & splitting the ceiling light & fan & wall light. The breaker switch that served the bathroom also served one bedroom with 3 outlets & one ceiling light (an overall total of 4 outlets, three lights, & one exhaust fan tied back to one single breaker 110 switch) (I do not think the switches count). Excuse me if my description sounds fuzzy. I don't know the code, but seeing that j-box on top of my ceiling joists, & with no cover plate just does not look right. FYI?
Thanks for the clarification
Great job Ryan. Question, you addressed the 6 ft 7 ft issue , what about 300.4(D) also in 320.23(B) The 11/4 in rule. The board in you picture is only 1/2 and the wire is stapled on the edge. Within the 7 ft, doesn't 300.4(D) also apply??curious
It only applies where screws or nails are likely to penetrate, so it depends on whether the space will have drywall installed.
a few questions about the accessible attic part I'm still an apprentice, what does code mean by wiring needs to be protected for permanently installed stairs, ladders (etc etc) access into the attic. Would we have to run 2 by 6 Strip guards everywhere that the cabling is travelling? What if the cable is running on the side of joists or trusses instead of onto of them? Protected seems a little vague or can be interpreted in different ways. Running wire on the side of joists or trusses instead of over them be counted as protected? you wouldn't be able to step on it. Stuff like that.
Hi Zappy Man. You would need to lay a guard strip (such as a 2x4) next to the cable if the cable is on top of the joists, truss chord, or whatever you are standing on. You would also need to install it next to the cable if the cable is on the surface of the studs, rafters, or truss chords that run vertically. Essentially, you need to be walking on wood, not wire, and if you imagine yourself falling down in the attic (not through the ceiling, but sort of sideways) you would need a board to break your fall instead of the cable doing it.
@@RyanJacksonElectrical Ok that makes sense now. For some reason I thought protected meant like it had to be armored or something like that. Thanks for the response! You're video's are really helpful to watch!
Great info Bro
can you mitigate this by removing the permanent ladder?
Does protecting the wire still apply in retrofit situations? What about vaulted ceilings? For instance, I fished Romex through my vaulted ceiling to install a light. And my attic is accessible by a permanent set of stairs. But the vaulted ceiling is not easily accessible (which is why I chose to fish Romex). If it does apply to my house, I just think its an incredibly onerous statute.
Regarding retrofit applications, what you install needs to comply [90.2(A)]. The Code is not retroactive. As far as a vaulted ceiling is concerned, I personally wouldn't require the protection. According to the IRC and IBC (unless they've changed recently), an attic only needs an access if it has at least 30" of headroom for a 100 square foot area. Most vaulted areas don't have that space, and if they did I still don't see a homeowner swimming around up there. But that's just my opinion.
@@RyanJacksonElectrical Would there be a way to combine the 30" guideline with the 7-foot protected height rule so that wiring run around the perimeter of a sloped roof attic (in areas less than 30-inches in height) would not require protection? Realistically, it would be pretty difficult to step on or store objects on a cable run in this space.
So If NM cable is used in walls and 2-3-4 wires are stapled on studs to enter a lightbox and there is foam insulation in the walls we have to adjust?
I think a good code change should be 6-8-10 feet from the attic access need protection and IF the attic will have/ flooring/ decking etc then it needs to have the wires in drilled holes etc most of the time alot of attics/areas wont be used for storage. I has to stop somewhere ( ya cant stop stupid) , next will be protected over bath fans etc I myself usually staple my wires to the sides of the joist and build a trough for the wires to sit in.. Been watching your videos for yrs and on Mike Holt Thanks for helping
This is good information
All cables? I guess this is applicable to cables carrying high voltages with the exception of cables carrying low voltages, right? Such as HVAC relay, door bell, Ethernet etc.
This brings up a question on the attic subject. If I use MC with THHN inside, is that consider a protected cable run in an attic? Or will boards still be required? It's a small house so the added cost of MC isn't going to be a huge factor. If MC isn't protected, would PVC or steel conduit count as protected? I may end up with conduit in the walls for some kind of blown in or foam insulation, the conduit would let me run new wires if I ever needed to fix something.
Depends on the AHJ if he/she considers MC still subject to physical damage..
What if the attic access is in a wall instead of a ceiling & has no ladder or stairway just a removable board? I would assume that since there is no ladder or stairway it would not need protected a loophole perhaps?
If the attic access is in a wall than it is my opinion that it is permanently accessible and would require the full protection. I am visualizing an attic access in the second floor of a home where you have a door in the wall that gets you into the attic space.
How about conduits installed inside attics feeding a/c units ,sub panels etc. Is there a Temperature adjustment table
Just the typical temperature correction tables.
Ryan, what about MC on trusses? 330.30(C) states "horizontal run of type MC cable installed in wooden or metal framing members or similar supporting means shall be considered supported and secured where such support does not exceed 6' intervals." Most guys I talk to say this applies only to holes in metal studs, not on top of trusses. Where 330.30(C) says "installed in wooden or metal framing members" does it refer to the holes, or atop trusses or both?
Just holes.
I agree but I would put a staple in the middle of that romex run to the guard strip.
how would you protect the wires in the attic with a permanent stair or ladder ? would you run all your romex up high and then drop down to the boxes , if so what is required to protect them.
Where possible you would run them parallel to the framing members.
Does the NEC permit NM cable to be run on top of joists in an attic without securing it with staples? I see words like “in” and “through” but not “on”. Plus, my 2017 Handbook commentary explicitly states that draping is not permitted. Thanks
Securing is required.
4:29 Just wondering how stapling the wire to the truss plate is protecting it. Great videos.
It is lower than the bottom chord of the truss, so nobody would be stepping on it.
@@RyanJacksonElectrical that makes sense now. ty for the knowledge.
Good points
Good info , thxs
Does the rules in 320.80 reference bypass the exception dealing with 10ft or 10% found in 310.12 (I think that's the correct section, feel free to correct).
Nope, that allowance still applies 310.14(A)(2) Ex]. It is one of the small differences between 320/330.80 and 334.80.
Thanks for both the info, and correction.
So regarding attic, what if the cable is running through the the framing member instead on top?
It needs protection if it is within 7' of the floor.
What year was this code applied to homes
So, I come along and innocently install a nice attic ladder in my 50 year old house and BAM, I need to protect ALL of my Romex, even though I physically cannot even reach half of it lol.
I don't have a 2020 book. Too expensive to buy every 3 years. Used to be if there was 4ft or less clearance then you did not have to place gards. Is that still the case? As in, run the wiring around the outer edges of attic.
That was never the case (at least, not in the last 30 years).
@@RyanJacksonElectrical it was code at one time. If the head space was under something like 48" you did not need gard strips because no one could walk there.
@@nooneyouknowhere6148 I just glanced at the 1971 NEC, it wasn't there.
@@RyanJacksonElectrical I'm pretty sure it was there in the 80s. It may have been an exception rathrr than the rule.
In 334.30 NM Securing and Supporting, the commentary of my 2017 handbook says “Draping the cable over air ducts, rafters, timber’s, joists, pipes, and ceiling grid members without securing the cable with approved means is not permitted except, as allowed in 334.30(B)(1).” Another nationally recognized instructor agrees with this and says cables running perpendicular across the top of attic joists are to be stapled, but when I discuss this with electricians in my area they look at me like I’m crazy. Apparently, nobody staples on top of joists in my area, much less run protective strips. Am I missing something? I’m more of an industrial electrician, so I’m not familiar with what inspectors enforce or ignore. Is this something that inspectors just ignore? Similar issue with cables coming down studs. Many guys just jam several cables under large staples resulting in insufficient distance to the edge of the stud rather than using a cable stacker or simply running half he cables down the opposite stud. Is this just lax inspectors? I don’t think either issue is terribly critical, although a screw in a conductor was reported to have started a fire in a relatives house.... I just can’t get my head around how some things are enforced and some things are not. I expect it’s difficult for a new inspector to come into an area and change the way people have been doing things for 50 years... Sorry for the long message, but this has bothered me for a long time. Thanks for your awesome content!
I'm not sure what you mean by, "every stich of wiring needs to be protected" in the attic. As I read the code it says if the wire is run along the face of the rafter, or in the case of a ceiling or tie rafter, it needs to be protected if within 7 feet of the floor. This says nothing to protecting wires run in/through rafters. Only cables installed on the face of a joist or rafter. This is to prevent tripping and snagging the wire.
I meant that only to emphasize that it is more than those cables that near the attic access.
Honestly, while some of this seems reasonable for solving some safety issues, much of it does not. Two MCs crossing each other and contacting each other for a fraction of an inch or fire caulked or foamed in a hole through a framing member require ampacity correction? Where's the data to support that? Will some company start marketing a small plastic spacer that will eliminate (for just a few pennies) the need to make that ampacity correction? What especially doesn't make sense to me is that we are now installing more individual circuits than ever before in the typical house, we're installing way smaller lighting loads than ever before due to LEDs, portable heating and cooling loads are less common than ever before, but we're required to do more ampacity corrections than ever. It almost seems like we're at a point where we could eliminate tons of calculations by making a blanket reduction in allowable ampacities for our common conductor sizes (i.e. reduce 14 AWG to 10A, 12 AWG to 15A) which would make the corrections moot but would potentially increase the use of copper. Regardless, it seems somewhat ridiculous as overloaded circuits and the ensuing overheating of cables now seem extremely rare as does the likelihood that new installations will cause them if everything is installed to code minus the correction factors. I could be mistaken, but it seems most electrical fires happen at interface points (receptacles, lighting outlets) and not as a result of overloaded wiring systems. Wouldn't it make more sense in that case to increase the quality and safety requirements on those interface devices rather than over-engineering the delivery system? It's just a thought...
Protection is certainly needed when a HVAC system or water heater is in the attic , But walkway should be installed Sometimes the wire gets on top of walkway. Lowest bid you know
Morale of the story, don't install permanently installed stair or ladder until you get your certificate of occupancy. I had a friend who put some of his belongings up in his attic before he got his certificate and the building inspector made him get his engineered trusses redesigned and retro fitted for " storage" before he could move in. Don't know if he had to change the wiring.
Safety first!
Could you make a video on how use the nec..
I have one.
kzhead.info/sun/h7ihpap_f2eBZoE/bejne.html
Also 300.17 references among others 300.4(D) seems like many of us miss these subtleties..?
I don’t know…, I think a pulldown stair is not permanently installed. You can fold them up and put them away but a staircase is permanently installed because it’s always there and cannot be moved
why do you have cables in the attic at all? i don't remember seeing that over here in europe...
It's quite common for electrical runs to be located in unfinished attic spaces in the United States.
@@jeffw8057 thru wall tubing, small electrical boxes 9 feet up, fuse boxes on mains entrance...and concrete/bricks houses...but your way is faster...
@@ivok9846 Similarly, for homes with basements, it's also common to have runs in unfinished basement ceilings.
@@jeffw8057 well yeah, you have all that empty space, so you use it when it's accessible...
Here in the Chicago land area is all conduit thats all we do
I would not call a pull down attic access “stair” a permanent stair as it does not meet any of the requirements of an IBC defined stair, egress or not. Same goes for ladders. Different codes here but IBC references NEC. I agree with your interpretation of the overall code section intent. I just disagree with defining a pull down access ladder as permanent. Permanent to me means “ready to use”. Pull down requires a minimum level of set up to use. I’m really enjoying your videos. Appreciate you sharing your knowledge. Thanks
Fair enough, but I would call it a ladder, and I would call it permanently installed.
My perspective is it comes down to safety.. Is the ladder readily accessible to young children or mentally disabled? What if they climb up there and accidentally pull a cable out of a fitting or connector and cause a safety hazard or damage to the cable in some other ways? I see no problem with unprotected cabling when accessibility requires responsibility to be placed on a parent or guardian.
Run conduit. How damn hard is it?
I have a feeling the cable going thru a hole is being misunderstood and is going to cause unessesarry expences.
Re upload?
?
The good news is there’s no fret area in this particular section of the code.
time to yank the ladder out
I live in Jacksonville florida and around here that 320.23 is not applied as it should be.( same misunderstanding). Same with the ampacity adjustment in wood framing holes sealed with fire clay or foam.But it is what it is Ryan. I might become inspector and start correcting a couple old habits electricians have around here 🤣🤣🤣 They are gonna hate me 🤣
DUUUUUVVVVVVAAAAALLLLLL!!! With that being said, I've never seen protection for wires in an attic... I've been in a LOT of attics
I can't find any of this in my 1972 code book.
There is no 1972 code book...
@@RyanJacksonElectrical I meant to say 1947 code book. But I'm glad you caught the joke.
I'm in industrial, not residentia,l electrical engineering. Designing a panel, for me, always take 3 times the expected time. When the "checked by" stage happens, all I get is a pat on the back. I want criticism more than anything but get obligatory compliments. Seriously sucks because I can design a bomb and(bless him, but the inspector has no clue what to think...would not even understand). Engineers that do CAD too need feedback. Why? CAD is CAD and gets very, very tiring(way tired of it today) and needs serious scrutiny from peers. But peers and inspectors sometimes ignore what they do not comprehend. Haha. My design for today. TGIF! Conscience will kick in again on Monday as it always does.
ima start a side-side business converting permanent access to more child proof temporary access...regulatory changes...when one door closes...another opens...like prison
Nail guards galore...
Greetings: Interestingly ironic: NEC is USA. Yet they choose 2 use metric temperature units. Typical law making mentality in 4getting the KISS idea.
TBH your US regs are nowhere near as complicated as the UK regs.