# Stupid Stuff In The Code



## micromind (Aug 11, 2007)

In light of the recent #14 on a 20 amp circuit thread, I thought it'd be appropriate to make a new thread about idiotic stuff in our most precious code......

I'll start with conduit fill and de-rating. 

Conduit fill and de-rating is the same regardless if all conductors are carrying their full rated current or if some of them will very rarely, if ever, carry more than a few amps. 

Why......

It would seem reasonable that non-continuous loads would be considered differently than continuous ones thus allowing more wire in a pipe without having to de-rate as much.


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## Forge Boyz (Nov 7, 2014)

Conduit bushings on PVC pipe...

Sent from my SM-G970U1 using Tapatalk


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## A Little Short (Nov 11, 2010)

AFCI (Arc Fault) breakers for ANYWHERE!!!


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## HertzHound (Jan 22, 2019)

micromind said:


> In light of the recent #14 on a 20 amp circuit thread, I thought it'd be appropriate to make a new thread about idiotic stuff in our most precious code......
> 
> I'll start with conduit fill and de-rating.
> 
> ...


I think there’s an exception for engineering supervision. Not sure if anyone ever uses it. But if you could get it engineered (run the numbers) you could get away with a lot more. Like theater lighting. Especially now with LED theater lights. Back when they were a 300w bulb, you could calculate that into the conduit derating. There would only be one 300w fixture on a dimmer/ckt, and one light rail could have twenty fixtures/receptacles on it. If the engineered drawings said you could pull 40 #10 in a 2” conduit, you could do it. Probably if you did it on your own it would fail.


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## macmikeman (Jan 23, 2007)

That code section that says the AHJ can interpret codes any way he likes at any time............ 

That code section that says neat and workman like without a good proper description other than straight and plumb. 

That code section that says within 5 foot of where the water pipe enters the building without saying interior side vs exterior side. 

That code section that requires handle ties for multiwire branch circuits.

That code section requiring re-identification of switch leg white's. (although I admit I am getting really used to it now after what - 20 years of having to do it?)

That code section requiring gfi protection for dishwasher circuits.

That code section requiring all gfi's be "READILY ACCESABLE" instead of just accessible. 

That code section that is not a code section at all where MTW is forced to use insulated romex staples.....

The code section on bundling of cables since they pulled their theories of how hot the cables might get out of their asses. 

The code sections where using wood molding over nm cables is disallowed everyplace in the first world except for Hawaii which is much more progressed than anyplace else on the planet because of wood mold use. 

The code sections that require shoes instead of leather flip flops. 

and ........ ....... ........ the stupid rules about box fill................ for plastic boxes..........


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## MTW (Aug 28, 2013)

20 amp circuits in dining rooms, 3 watts per square foot for dwelling units, bundling rules for cables in drilled holes since they almost never see a full load, no NM cable above dropped ceilings in other than dwelling units, requiring ground rods, dwelling unit load calculations resulting in oversized services...just to start.


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## macmikeman (Jan 23, 2007)

There is some good codes too though..... 25 foot clearance over swimming pools. Mikey likey..... Gfi for the pool light and equipment. Fast Egress doors for vaults. No more solder only connections. Minimum wire size #14 for general wiring. Those kind. 



.............. We are............

...........................Too rough.........

..............................................On code writers and acceptors........


.........................................................................................Sometimes. 

But we should be able to slap rules and regulations on them as well just so they understand that stupid stuff stupid people write up as law can be a drag.


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## micromind (Aug 11, 2007)

540.13 Conductor size. Conductors supplying outlets for arc and xenon projectors of the professional type shall not be smaller than 8 AWG and shall be of sufficient size for the projector employed.

Apparently, if I hook up a rectifier and the nameplate states less than 24 amps (I've seen them as low as 8 amps) I need to run #8 from the panel to the rectifier. 

Yes, this is being nit-picky but it shows just exactly how ridiculous the code can be.


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## CoolWill (Jan 5, 2019)

There is no stupid stuff in the code, just ask Incognito or Weasel.


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## 99cents (Aug 20, 2012)

Hey, look! Another code bashing thread. Imagine that.


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## CoolWill (Jan 5, 2019)

99cents said:


> Hey, look! Another code bashing thread. Imagine that.


Oh no! How dare professionals with field experience disagree with superior desk-riding code makers! The government should step in to silence these heathens lest someone think for themselves!


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## CTshockhazard (Aug 28, 2009)

*Too many to list....*



> *334.100 Construction.* The outer cable sheath of nonmetallic-sheathed cable shall be a nonmetallic material.


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## 99cents (Aug 20, 2012)

CoolWill said:


> Oh no! How dare professionals with field experience disagree with superior desk-riding code makers! The government should step in to silence these heathens lest someone think for themselves!


Maybe you’re right. I’m just tired of the “code is optional” chants around here.

Derating rules confuse me and I have yet to get a straight answer from inspectors and the desk jockeys around here. I just end up with my own interpretation.


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## CoolWill (Jan 5, 2019)

99cents said:


> Maybe you’re right. I’m just tired of the “code is optional” chants around here.
> 
> Derating rules confuse me and I have yet to get a straight answer from inspectors and the desk jockeys around here. I just end up with my own interpretation.


If code was automatically synonymous with safety, then I would agree. But it is not maybe 30% of the time. Safety isn't optional. I don't think anyone here is arguing against safety. As in your own example of derating, your practical field experience far outstrips anything those government employees at the inspection office know, and by light years on the code committees.


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## Incognito (Apr 14, 2019)

CoolWill said:


> There is no stupid stuff in the code, just ask Incognito or Weasel.


Oh there definitely are stupid ones, like the one that does not allow you guys to mount a panel sideways. 

Now was that one also because of the manufacturers? Lol


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## 99cents (Aug 20, 2012)

Incognito said:


> Oh there definitely are stupid ones, like the one that does not allow you guys to mount a panel sideways.
> 
> Now was that one also because of the manufacturers? Lol


It goes back to the “down is off and up is on” mentality. Like gravity is going to turn a sideways breaker on.


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## zac (May 11, 2009)

Incognito said:


> Oh there definitely are stupid ones, like the one that does not allow you guys to mount a panel sideways.
> 
> 
> 
> Now was that one also because of the manufacturers? Lol


It has to do that 90% of Canada's population live within 100 miles of the U.S. boarder. This causes a gravitational effect
on the panel. 

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## 99cents (Aug 20, 2012)

I do wish they would make an upside down panel directory  .


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## Incognito (Apr 14, 2019)

micromind said:


> In light of the recent #14 on a 20 amp circuit thread, I thought it'd be appropriate to make a new thread about idiotic stuff in our most precious code......
> 
> I'll start with conduit fill and de-rating.
> 
> ...


So the load on the wires dictates conduit fill in the NEC? Or am I misunderstanding you?

In the CEC, fill is fill, regardless of load. The load only dictates the allowable ampacity of the conductors


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## tjb (Feb 12, 2014)

I do wish we could staple small NM to the bottoms of joists in a crawl space or basement. 

334.15(C) In Unfinished Basements and Crawl Spaces.
Where cable is run at angles with joists in unfinished basements and crawl spaces, it shall be permissible to secure cables not smaller than two 6 AWG or three 8 AWG conductors directly to the lower edges of the joists. Smaller cables shall be run either through bored holes in joists or on running boards.


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## Dennis Alwon (May 9, 2009)

tjb said:


> I do wish we could staple small NM to the bottoms of joists in a crawl space or basement.
> 
> 334.15(C) In Unfinished Basements and Crawl Spaces.
> Where cable is run at angles with joists in unfinished basements and crawl spaces, it shall be permissible to secure cables not smaller than two 6 AWG or three 8 AWG conductors directly to the lower edges of the joists. Smaller cables shall be run either through bored holes in joists or on running boards.


Fortunately NC amended that section..Only in basements not crawl spaces for us.


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## Dennis Alwon (May 9, 2009)

micromind said:


> In light of the recent #14 on a 20 amp circuit thread, I thought it'd be appropriate to make a new thread about idiotic stuff in our most precious code......
> 
> I'll start with conduit fill and de-rating.
> 
> ...


So you expect the nec to have 50 rules for this issues depending on the amount of amps the circuits are using. Also how do you control if someone else is going to add more to a circuit. You really can't expect the installer to change the entire pipe run because previously the installer only figured it for 5 amps instead of 20 amps. 

They obviously look for the worst case scenario.


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## sparkiez (Aug 1, 2015)

Incognito said:


> So the load on the wires dictates conduit fill in the NEC? Or am I misunderstanding you?
> 
> In the CEC, fill is fill, regardless of load. The load only dictates the allowable ampacity of the conductors



The load on the wires introduces extra heat into the conduit, which further heats the wire, which then increases resistance, which then produces more heat until some kind of equilibrium is met. It makes perfect sense once you wrap your head around the concept that the resistivity of a material depends on the composition of the material, it is non-linear, and it is temperature dependent. Given that we can only have certain material purity levels, and the wide variety of circumstances a conductor can be exposed to, those values were determined experimentally and a safe threshold was set.


Why so much complexity? The same reason panels are much lighter than they used to be and use much less material. They have been engineered to use only the material required to meet their usage needs. The same goes for modern cabling and building systems.


Material science has only been a real thing since about the 50's or 60's, and is a major driving force behind these innovations.


Now, back to your actual question:


1. Determine the loads to be served by the raceway.
2. Determine circuit ampacities.

3. Size the wire. - Preliminary size.

4. Apply derating factors for the circuits in the raceway (number of conductors).
5. Determine the required conductor size with derating factors applied.
6. Size your raceway as normal


Also, to touch on Mech's comment about the subject, I absolutely agree that you should be able to derate less based on the duty cycle of equipment, but I believe the reason this is left out is that the calculations can get very difficult very quickly and I wouldn't expect the vast majority of electrician's I've worked with to be able to perform them. Unfortunately, we can't do hard-and-fast rules for situations like this, because there is a reason the rule was made in the first place.

Arc fault breakers - huge expense to the home owner. I agree here. The thing is, I've also seen burned up receptacles and such that were arcing like crazy / worn out / overloaded / etc. Power strips daisy-chained together and overloading a 15A receptacle, but on a 20A circuit and over time starting small fires. Generally, the box will catch the sparks and flame, but if some knuckle-head has done work, not always. This particular reason is why I support arc-fault breakers.


Generally, even though I may not agree with the code, I know that it is my job to build to it, regardless of my opinions on the subject. I also know that there is a process for something to become code, and that I am free to submit proposals of my own.


https://www.ecmag.com/section/codes...ocess-behind-submitting-proposals-nec-changes


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## FishinElectrcian (Jul 18, 2019)

Well I don't know if that quoted right.. Still new. But with regards to safety I think the Code (CEC for me) is pretty good. They've made a lot of changes especially in the writing to make it simpler to find. I do have some complaints about how TES (BC) is handling their updates.

I miss the old crown publications where they mailed you every update and you changed pages out of the ring binder. Archaic but every time an update package came you leave through all the changes. Now I have to go digging on their website to find stuff or look for heads ups from the inspector.

Favourite question on the CSTS exam for working in Fort McMurray: 
"Safety is common sense. T/F?"

Almost failed out of getting to the Mac.. The answer is false because not everyone has common sense. Haha.


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## FishinElectrcian (Jul 18, 2019)

And who doesn't hate AFCI's? 

What that's doing to the quality of wiring in the panelboard as in clutter and filling up the spaces so we have to use piggybacks with tie handles rather than full module breakers for heating loads to save space for random outlet circuits. Bah! 

Then with added cost for these branch circuits at $80+ per AFCI it doesn't make me want to run as many homeruns as I have traditionally. 

Then there's the brown outs here that knock out every afci/gfi in the panel. Or an open neutral in a storm that now fries $1000+ in breakers.

The concept I guess is sound maybe, but in practice causes more problems indirectly


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## HackWork (Oct 2, 2009)

99cents said:


> Maybe you’re right. I’m just tired of the “code is optional” chants around here.


Why? It's true, the code _is_ optional, just like the law is optional. And you break both of them.


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## Incognito (Apr 14, 2019)

sparkiez said:


> The load on the wires introduces extra heat into the conduit, which further heats the wire, which then increases resistance, which then produces more heat until some kind of equilibrium is met. It makes perfect sense once you wrap your head around the concept that the resistivity of a material depends on the composition of the material, it is non-linear, and it is temperature dependent. Given that we can only have certain material purity levels, and the wide variety of circumstances a conductor can be exposed to, those values were determined experimentally and a safe threshold was set.
> 
> 
> Why so much complexity? The same reason panels are much lighter than they used to be and use much less material. They have been engineered to use only the material required to meet their usage needs. The same goes for modern cabling and building systems.
> ...



In the CEC conduit fill is so much easier. Can’t fill a raceway more than 40%, that’s it, that’s all. (There are exceptions but 90% of the time that’s all you need)

Now how many amps are you allowed to put on those wires in the raceway? That depends on how many are in there and if they are current carrying etc etc.


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## Incognito (Apr 14, 2019)

99cents said:


> Maybe you’re right. I’m just tired of the “code is optional” chants around here.
> .



It kinda reminds me of high school when the kids that smoked and didn’t follow the rules (including me) used to brag and act as if they were cool for doing it, but in reality they are not. :vs_laugh:


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## sparkiez (Aug 1, 2015)

Incognito said:


> In the CEC conduit fill is so much easier. Can’t fill a raceway more than 40%, that’s it, that’s all. (There are exceptions but 90% of the time that’s all you need)
> 
> Now how many amps are you allowed to put on those wires in the raceway? That depends on how many are in there and if they are current carrying etc etc.



I don't think you are distinguishing between raceway fill and conductor derating. They are different things, and likely very similar or the same in the CEC.


This is raceway fill:
In the CEC conduit fill is so much easier. Can’t fill a raceway more than 40%, that’s it, that’s all. (There are exceptions but 90% of the time that’s all you need)



This is derating:
Now how many amps are you allowed to put on those wires in the raceway? That depends on how many are in there and if they are current carrying etc etc.


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## Incognito (Apr 14, 2019)

sparkiez said:


> I don't think you are distinguishing between raceway fill and conductor derating. They are different things, and likely very similar or the same in the CEC.
> 
> 
> This is raceway fill:
> ...


That was my question from the beginning. The OP’s first post made it sound like you sized the conduit depending on the ampacity of the wires, not just their size. 

To be honest, I didn’t even read your long explanation (post #23) fully either.


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## HertzHound (Jan 22, 2019)

It seems we’re the same for conduit fill. Over two conductors is 40% fill. Two conductors is 31%. One conductor is 53%. 

The thing that screwed using conduit for home runs, is the derating part. Once we were forced to use handle ties for multiwire homeruns, we were screwed. Now specs on most jobs are for separate neutrals. I guess they don’t want multiple circuits being shut off due to handle ties. If you ask me, they pretty much screwed the trade. Now it’s MC right to the panel. Why even bother with The hole illusion bullish!t of a trough and nipples down to the panel. Just a waste of time. 

The only way to make it work, in my opinion, is through BIM. If you know where all your conduit is going before they pour the floors, you can get your anchors in first. Get all your trapezes built through schedules from the model. Get the conduit in before everyone. Pull from barrels or get your measurements and prefab your pulls in the shop. If you can’t do that, it’s over.


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## sparkiez (Aug 1, 2015)

Incognito said:


> That was my question from the beginning. The OP’s first post made it sound like you sized the conduit depending on the ampacity of the wires, not just their size.
> 
> To be honest, I didn’t even read your long explanation (post #23) fully either.



The long explanation was because there were some other people on here complaining about being forced to derate a circuit. I guess I just took for granted that using the words "conduit/raceway fill" and "derating" implied two separate tasks when sizing a raceway and branch circuit conductors.


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## micromind (Aug 11, 2007)

sparkiez said:


> I don't think you are distinguishing between raceway fill and conductor derating. They are different things, and likely very similar or the same in the CEC.
> 
> 
> This is raceway fill:
> ...


The de-rating part is what I was referring to.....it has a direct effect on conduit fill.


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## Incognito (Apr 14, 2019)

micromind said:


> sparkiez said:
> 
> 
> > I don't think you are distinguishing between raceway fill and conductor derating. They are different things, and likely very similar or the same in the CEC.
> ...


How? Isn’t fill just 40% ?


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## micromind (Aug 11, 2007)

Dennis Alwon said:


> So you expect the nec to have 50 rules for this issues depending on the amount of amps the circuits are using. Also how do you control if someone else is going to add more to a circuit. You really can't expect the installer to change the entire pipe run because previously the installer only figured it for 5 amps instead of 20 amps.
> 
> They obviously look for the worst case scenario.


I see your point, and they certainly need to look out for the worst-case.....usually......

How about something as simple as an exception to table 310.15(B)(2)(a) (the de-rate table).......When a conductor supplies a fixed-in-place load and the rating of the load is 50% or less of the rating of the conductor, it shall be counted as one-half of the number of current carrying conductors. 

Maybe also, a conductor that supplies a non-continuous load shall be counted as one-half of the number of current carrying conductors. 

Yes, I didn't write that very well but what I'm trying to get at is the code needs to recognize that when a conductor, by the nature of its installation, cannot produce as much heat as fully loaded one, an exception should be in order.


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## HertzHound (Jan 22, 2019)

Incognito said:


> How? Isn’t fill just 40% ?


It’s like this. 

Ckt 1,3,5-N 7,9,11-N 13,15,17-N plus ground = nine current carrying so derated at 70% you can use #12 at 20 amps and pull it all in a 3/4” conduit and be at 32% fill. 

With handle ties. 

Ckt 1-N, 3-N, 5-N, 7-N, 9-N, 11-N, 13-N, 15-N, 17-N plus ground. Now you have to derate eighteen current carrying @50% and run #10s and pull it in a 1-1/4” C. 26% fill. There’s room for one more circuit, but then you have to go to # 8s 

Instead pull 12-2-3 MC right to panel three times. Done before you can get the EMT off the rack. And the said any monkey can run EMT.....


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## emtnut (Mar 1, 2015)

sparkiez said:


> Why so much complexity? The same reason panels are much lighter than they used to be and use much less material. They have been engineered to use only the material required to meet their usage needs. The same goes for modern cabling and building systems.


So if they made panels heavier, we could fill conduit > 40% ??

Cool :biggrin:


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## emtnut (Mar 1, 2015)

....


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## Incognito (Apr 14, 2019)

HertzHound said:


> Incognito said:
> 
> 
> > How? Isnâ€™️t fill just 40% ?
> ...


 I Understand what your saying. Depending on how you run the wires and how many wires you choose to run in each conduit can change the design and what is required but in the end, the one thing that defines The size of conduit needed is the 40% fill, not the ampacity of said wires


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## HertzHound (Jan 22, 2019)

Incognito said:


> I Understand what your saying. Depending on how you run the wires and how many wires you choose to run in each conduit can change the design and what is required but in the end, the one thing that defines The size of conduit needed is the 40% fill, not the ampacity of said wires


Yes. 

I’m just really pissed with the handle tie rule. Your lucky you haven’t changed. You must have better educated electricians up their that know how to mark junction boxes, and know not to use devices to splice neutrals of multiwire circuits.


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## sparkiez (Aug 1, 2015)

emtnut said:


> So if they made panels heavier, we could fill conduit > 40% ??
> 
> Cool :biggrin:


Yep, exactly. What genius :vs_laugh:


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## sparkiez (Aug 1, 2015)

micromind said:


> How about something as simple as an exception to table 310.15(B)(2)(a) (the de-rate table).......When a conductor supplies a fixed-in-place load and the rating of the load is 50% or less of the rating of the conductor, it shall be counted as one-half of the number of current carrying conductors.



I mean, that could work, but in practice what I see is people just ignore de-rating all together. Most of the time, it is fine, as the loads aren't that large. There are times it isn't. We had a historical building catch fire, and the cause was determined to be electrical, and it was found that the electrician had not derated the wires in some conduit. It was determined that he was at fault for the fire.

I'm not sure what happened to him as he disappeared soon after that.


To answer Incognito:
When you derate you have to increase conductor size. This is how it effects your conduit fill.


You are stuck on this 40% thing. 40% is only the fill percent. The fill percent and the conduit fill are different things.


percent fill is the fraction of the total cross-sectional area allowed to be filled in the pipe.


Conduit fill referring directly to the size of the pipe needed to accommodate the circuits needed.


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