Mike Holt Live Q&A, Thursday, May 21st 2020

[Music] hi this is mike holt with michael.com i think this is like video number 15 or 16. and uh just wanna take a moment thank god for giving me the opportunity to make this difference in your lives and i'm having a great time i'll get some bad news for you though later today i'll tell you all right service and feeder conductor sizing a lot of times i get a lot of questions on this mike you stated that if a job specified at 400 amp service then 400 amp conductors must be used and we couldn't use 500 kc mills well i'm quite sure i said that so let me review it if you have a contract with somebody and in your contract you simply say provide 400 amp service and you use 500 kc mills well if you go to table 3 10 16 and the 20 20 code 500 kc mills at the 75 degree c column is rated 380. now you can say well i got a 400 amp service because the rating of the circuit which is not really a code rule doesn't say this for peter's on services is the 400 breaker well maybe a judge would believe that but i got a feeling if somebody expects a 400 amp service they're expecting 400 amp wire just saying so i'm not saying the code tells you that you have to have 400 amp wire on a 400 breaker so i don't want to miss on this misunderstand what i said i'm just saying the practice is what put 500 casey mills on 400 amp breakers michael we've been doing it for probably 125 years i'm not everybody being sued about that well yeah i agree with that now conductor sizing now this is a separate question conductor sizing specified in table 310.12 for dwelling units are smaller one second let me just edit that thing there oops what happened here are are smaller it looked me then table 3 10 16. do the electrons know that i added the sentence myself do the electrons know the difference between a dwelling unit and other occupancies well let's take a look at table 310.12. this is a very interesting table as a matter of fact in the 2020 code i submitted a public input to have the table completely removed because it is full of errors it violates the code but it's been there for 100 something years mike how could you have it removed well it's been wrong for 100 something years that's all i can say what do you mean it's wrong well let's take a look at it see why it's wrong first of all table 310.12 has to do with single-phase dwelling unit services and feeders without me getting into all the details right now this is used anytime the entire load of a dwelling unit is on the service conductors and or on the feeder connections if you're supplying the entire load but only for a dwelling unit that means for one unit now it could be for a dwelling unit for a single family dwelling it could be for each dwelling unit for a multi-family building like it could be a duplex and you can use this this for each of the feeders of each dwelling unit and it could be for you know 100 unit building and you can use 310.12 for each of the individual feeders where it carries the entire load by the service say okay well mike we've known this table this table was around and then they they switched it back a couple code cycles and i made it 83 percent rule which we'll talk about that but look let's look at how it is right now the way it's always been nothing has changed if you have a hundred amp service this table tells you that you can use a four gauge copper conductor but if you're a 100 amp service if you go to 110.14c1a one actually it's a one a one a one two it tells you that you have to size the conductors to the 60 degree c terminal four gauge wire i'm sorry if i go to the 60 degree c column it's only rated seven amps and this crazy table tells us that we can use a four gauge wire on a 100 amp breaker under the 60 degree c column of three 110 that 14c one a two that's a problem because now you have let's say you use 75 degree seat mic what about if the terminal is rated 75 degrees see aren't they all rated 75 degrees c yes okay so let's deal with reality okay we'll go back to reality then let's go to the 75 degree c column what is 4 gauge conductor rated 85 amps you can't put an 85 amp breaker on 100 amp breaker the rules of conductor over current protection 240.4 says you have to protect the conductors at its opacity except as permitted in a through g and then you go to 240.4b and it says hey the next size up rule is permitted as long as you don't exceed 800 amperes well a four gauge wire is rated for 85 amperes you can't put it on 100 breaker because the next size up breaker if you go to 240.6 a is a 90 amp breaker so that's a problem okay what about if you had a 225 amp breaker well three odd if you go to table three odd it's rated 200 amps how can you put a 200 amp wire and a 225 amp breaker mike i know i'm with you that's why i said submitted a public input to remove it and then it goes on it says well it's a 400 amp breaker if you have a 400 amp service it says you can use 400 kc mil conductors rated 335 amps are you kidding me that makes absolutely no sense at all why on a dwelling unit would you be able to have a wire neck size next size up protected when 240.4 does not recognize that you could put 335 amp wire on a 400 breaker 240 at 4b does not recognize to put a 200 amp wire on a 225 amp breaker you know why the reason this table is here is everybody knows that when you do residential load calculations you get the answer that number is so far off it is so ridiculous so the guys on 310 which have nothing to do with overcurrent protection right they just made up their own rules they say well you know what if you're going to put in a dwelling unit you can put a 400 amp breaker and put it on 335 amp wire we're fine why well because the load's never going to be 335. well if that's true then why don't you go to 220 and then why don't you calculate the load to be what it is and then take 83 of that to find out the size service is going to be then you get the break then you go to 240.4 and you apply the normal overcurrent protection rules to conductor and pisces and you comply with 110.14c1 c1 let's just say one because there's an a b and a c there nc2 so let's go to 110. let's go to 310.12 rules which are ridiculous and i'm going to submit a public input to get them removed and if you're watching this video and you understand what i'm trying to say here you get some public inputs help me out here there's no reason to be having this crazy table but we're going to go with the table because that's what it says and we're going to say okay well we're going to go with the table ready for this now 3 10 that 12. dwelling unit service and feeder conductor supplied by single phase 12240 or 12208 systems can be used can be using uh 310 12a through d you say well why would you say 120 240 and 122.8 because at one time you could only use this value in this table when it was a 120 240 you couldn't do it for a single phase 122.8 for probably about 100 years this only changed a couple cycles in the past that's why they show it couldn't just simply say for a single face dwelling on the surface which is what i say in my book all right so now let's kind of go to the rules here says this service conductor supplying the entire load so associated with a dwelling unit could be sized per the table right there the entire load where there is no conductor and pass the adjustment of corrections required by 110.14 that means where you're not going to have more than three current carrying conductors and you're not going to have an opacity adjustment which we never apply correction because of temperature and we never apply adjustment because of bundling so therefore i'm i'm gonna go to the table like we've always done for under 25 years go to the table you size it so if you have a 200 amp service you go to table 200 servers it's going to give me two odd copper four out aluminum so that would be two odd copper and four adalum you know what i'm gonna have to start doing i'm looking at my graphic right now you don't know that this is copper because i didn't say it's copper and i know i can make a general statement hey guys if i don't say it's copper then it's considered copper i don't think it's fair because unless you caught that statement somewhere in my book you might not know this so i think i'm going to start in my graphics and in my text to make sure to make a double check let's just say two odd copper if it's copper see you all right now it's a comment i'm making in my book so this is all for my book section 310.12 cannot be used for service conductors for two family dwellings are multi-family dwellings see right here you can only use it for a single dwelling unit not for duplex not for multi-family now if you have to do a correction or an adjustment it changes a little bit they say well you can't use a table then what we need you to do is we need you to size the conductors to 83 percent of the opacity of the service disconnect 200 amp servers take 83 of that that means you have to have 166 amp wire so now you have to 166 amp wire after you apply any correction and adjustment so if you applied correction and adjustment well then we would have to take the 90 degree c wire which i'm not planning on doing opacity for whatever the conductor we're going to use and then i have to make sure after i adjust it and correct it and adjust it that it's going to have an opacity of 166 amps okay we're never doing that and guess what the answer's still going to come out the exact same thing that we started with so we're going to skip it but that's why the 83 percent rule is in there because without having an 83 percent rule then what happens if you did adjust the correct correct opacity how did you then size it when it was only a table so if not if there's any adjustment or correction you don't use a table you do the calculation which is going to give you the same thing as the table by the way 83 of the service rating is how they made the how the table was originally created that's what the 83 percent came from okay now watch this remember this feeder conductor supplying the entire load associated with the drilling unit can have the conductor size to 310.12. so we see a was talking about service conductors which goes to the table b is talking about we probably should point to these conductors right here a little easier well this is the feeder here's the right here's your server yeah let's point it up here because it'll be a little easier to see that this is the feeder conductor so here's the service conductors and the feeder conductors you can also apply 310.12 but only if what you carry the entire load so if you put like a meter main outside and you have a main breaker outside and then you have positions for additional breakers which is and then use feed through lugs well then you can't use 310.12 b for the feeder because the feeder does not carry the entire load supplied by the service so the service conductors you can use 310.12 but the feeder since it doesn't carry the entire load because you put a breaker in there for the air conditioner breaking it for the pool equipment a break in there for the heat pump a breaker and after a weld because it's all convenient to be outside maybe a breaker also for some other equipment out there well then you can't use it but 310.12 i think it says that i gotta find the exact word it says that the beta conductors are never required to be larger than the service conductors you see if this was a 200 amp service and we went to the code book code would require us to use triad right if it was just just the way the code would require well then the table said you could use two odd but the table can't be used on a feeder if it doesn't carry the entire load if you put a meter main out there with all these other breakers well then now it doesn't what that means you need to have what size wire with the feed through live with the 200 main breaker you need to have three out going inside two watt coming in the code recognizes that in no case do your feeder conductors have to be larger than your service conductors and that's going to be in 310 that 12 probably in b and i'll let you guys give me the exact reference number in there i'm not going to find it but it says it in there all right multi-family building all those individual 12 units 100 you can use the table um how do you size the peter it's just an example well if the feeder conductors if you have a 200 amp breaker well then you need feeder conductors to the table we saw the table that's going to be two out where if this had been not 310.12 we would have used three odd we already talked about this table that make any sense um now 310.12 cannot be used the size of veda conductors where the feeder does not carry the entire load by the service but all right i gotta find it get your cookbook out 3 10 at 12 3 10 14. okay i'm getting a 215.3 because it is there also but i want to see if there's anything here i'm going to read 310.12b for a feeder rated 100 amperes to 400 amperes the feuda conductor supplying the entire load associated with the one family dwelling or the feeder conductor supplied with the entire load associated with an individual dwelling unit have an opacity of 83 percent you have no adjustment applied table okay let's go to c in no case shall a feeder for an individual dwelling unit be required to have an opacity greater than that specified so that's the rule so it's right there in [Music] 310.12 c and you know what you should do you should make a note in there and brian that reference and there's another rule that says the same thing and that's going to be 215.3 what well that was a wrong reference oh so somebody just gave me a reference up the top of their head but there is a there was anyhow a 215 dot 2 and that would be 2 3 315.2 a three the feeder conductor capacity shall not be less than the service conductors no that's not it feeder conductors feeder conduction plant transfers your conditions okay no it used to be in in 215.2 and it's not but it is a 310.12. see i probably have a slide next to it we'll see if we do or not all right so here's an example with the adjustment of correction which we're not going to get with into see there it is i knew the graphics come in here feta conducts for an individual unit are not required to be larger than the service conductors mike let's change this graphic so we can put a main breaker coming in have a bunch of breakers outside and have feed through lugs going inside if anybody could take a picture in the landscape mode of an installation like that real nice pretty picture and send it to mike mikeholt.com we will give credit to your name on that image and then i would have a better graphic than i show here because i don't like this graphic not for that little bunny because you can't really tell all right neutral conductors that's a whole other world neutral conductors um it's a big deal you know what one day neutral i would like to have a whole program on everything there is about the neutral conductor how you size it how you can reduce it what about non-linear loads you know all kinds of things by neutral conductors don't know when it's going to happen i get bad news for you guys later and i'll tell you okay but this rule when you're doing a dwelling unit has a rule about neutral conductors it says look neutral conductors are permitted to be sized smaller than the phase conductors well the neutral conductor almost in all cases would be smaller than the base conductors because see the neutral conductor carries the unbalanced load so anytime you put a bunch of phase to phase loads like a water heater an air conditioner a heat pump a range or not a range um any other other 240 volt loads well they don't connect on the neutral so therefore you would size a service let's say 200 amps you might say it's a neutral at 105 amps so but it's saying hey it could be smaller which of course we're not if the requirements are 2 20 61 that's the rule talk about how you size the neutral and 230 42c for service conductors that's the rule that says that the neutral has to be sized a certain minimum size we're not going to get it to now and the requirements of 215.2 for feeder conductors are met again even for feeders your neutral conductor watch this this is kind of crazy you might have a three-phase load and the only thing you have is a bunch of receptacles let's say you know in a pump station somewhere it's all three-phase motors and you got a couple of lights and receptacles so therefore you have a neutral conductor going out to that panel but the neutral lotus let's say only 30 amps but you have a 400 amp feed going out to that that to that circuit well the neutral then if you only have 30 amps would be a 10 gauge wire and then your phase conductors might be 500 casey mills let's just say but both 230.42 take a look right here and 215.2 they say that the neutral conductor cannot be any smaller and the surface a little different than the feeder the feeder be no smaller than the equipment grounding conductor for the circuit but mike it's a neutral why would i size my mutual to the equipment grounding conductor i'll tell you in a minute and no less than 230 42c and i'm sure 250 2342c says can't be any smaller than given in table 250.102c which has to do with with with the minimum and 250 that 24c guys here's the here's the logic the logic is but what happens if a phase conductor faults to the neutral conductor when you have to make sure that that neutral conductor will be sized so that it can serve the purpose of the effective ground fault current path kind of lightweight in other words it has a low enough impedance so we're not going to get into the details but you know listen i'm hoping you guys are having fun learning this the graphics you know if you get my books their illustrations that that i can encourage you that this is what i do if you get a book and a video from me it's just fun i mean to me i'm having a great time hopefully you are if not see you you're gone right all right let's go on that's it on dwelling units and servicizing does table 310.12 make any sense absolutely not does it violate 240.4 rules absolutely so that's what it is so use the table size residential for sure unless branch you have any comments i'm going to jump on the brian circuit sizing just one real quick mike one of the guys said um let me back up here he says it seems like a risk to allow uh this for 122.08 when the neutral imbalance could be higher than on a 120 240 system and i think that was when you were talking about uh the 120 208 versus 122.40 okay quick conversation if you had a 200 amp feeder going to a dwelling unit okay you do the calculation 200 amps without getting into this this table stuff and let's say you calculate the neutral load is 100 amps so what size neutral would you run well forget about a dwelling let's just say it's just a circuit well if i have a 200 amp load i put three out wire and if i have 100 amp neutral then i would use a three gauge neutral and that is 100 what i would do because i did the calculation that was 220.61 and make sure it complied with 230 that 42c for the service and i'd make sure i comply with 215.2 for the feeder conductors but i put 100 amp conductor for the neutral 200 amp conductors for the feeder conductors now let's just assume that there was 100 amp calculated load how many amps is on line 100 how many amps is the line two line the neutral lows a hundred so then what would be the neutral current is zero but why these sizes are new to 100 amps because you could have all the kernel one line on and no current on the other line on and you'd have 100 amps on the neutral that's the theory in the logic okay got that but mike on a 120 208 wide three-phase four wire system and it says it and 220 to 61. then the neutral conductor even if you put 100 amps on 100 amps the neutral current there's a formula and i the neutral is equal to to a squared plus b squared plus c squared minus a b b c ac okay and you got to put a prince on that on that minus part and if you had 100 amps on line one you put 100 amps on the line too on a 120 240 volt system the neutral is going to be what zero but on 120 208 the neutral is going to be what 100 amps and that was the argument that was made for a hundred years saying that you could not use 310.12 that's now for 12208 because the heating of the conductors would have been greater now eric strongberg knows this and i got a feeling of this oh my my my this is not a 120 240 single winding where the current goes out the current backs here and it kind of goes this way and it kind of goes inside and goes back to the side like that when it's a 120 208 mic it's going to be out of phase by 120 degrees and the way i understand this because i'm not an engineer here is that the actual heating of a 120 240 volt circuit each phase conductor carrying 100 amps and the actual heating of those three conductors will be exactly equivalent to the same amount of heating on a 120 208 where each phase conductor is carrying 100 amps because this is a function of heat so we're going to find out and next tuesday i'll get you the actual answer if it's true if it's not true guess what doesn't matter because that's what the code says and that's what we're going to do but i'd like to know if it was true at least for 100 years we thought it was true that there was a difference and then it changed it had to be a reason it changed i don't know the reason somebody could do some research and tell me hey mike the reason i changed that that was done in 19 whatever it was or 2005. all right so i'm done with that let's go to branch circuits and equipment terminals this is a real toughy tricky one all right ready for this 110 14 c1a tells us that conductors one gauge and smaller must be sized using a 60 degree c column of table 3 10 16. so if this was one gauge and smaller then i have to go to the 60 degree c column for 100 breaker so let me see if i can get oh let me go back up here i should have added a table there sorry so let's go to this table here so 100 amp breaker oh got to go 60 degrees c i would have to use one gauge but if the terminals were rated 75 degrees c for 100 amps well look at this holy moly i can go from that's 60 i'd have to use one gauge but if it was 75 degrees c this is 60 75 90 degrees columns i can't show you the whole thing guys then that would be three gauge okay so we have to go to the tables based on the terminals so now on a 50 amp breaker at 60 degrees c you're going to use 6 gauge wire 100 amp circuits or less i probably should say that in the text in the bottom microwave and conductors one ought and smaller you half the size they're conducted at a 60 degree c column that really sucks that's what we used to do when we had tw and thw now 110 14c 1a2 is interesting it says that conductors with an insulation temperature rating greater than 60 degrees c are permitted which means that you can use th wn-2 and thw1-2 see this is something i didn't realize if you don't take my basic class on the code then you don't know this because i got asked a question like that's a really good question how would you know that unless you took my class he said mike well you'll see a little bit we'll get to that part conductor with insulation temperature rating greater than the six degrees c t h w n dash two is rated for 90 degrees c we need to point that that's a nine degree c wire but the conductor must be sized per the ampacity contained in the 60 degree c column you see 110 that 110 14 c1a1 says that you have to use 60 degrees c wire on 60 degrees c terminals that's what that one says then 110 14 c1a2 says well you can use higher insulated wires on terminals rated 100 amps or less using one gauge wire and smaller you can use a higher insulation rating but you're still going to have the size water six degrees c and then you go to 110.183 and that is everything that you really want to know about and that says look we're still talking about 100 amps or less conductors terminating on equipment rated 75 degrees c can be sized in accordance with the ampassa is contained in the 75 degrees c column of 3 10 16. that's the key to my knowledge i'm going to make a general statement and i'm hoping that i piss somebody off here that you guys will prove me wrong and then next tuesday or the next recording i can explain it i'm going to make a statement ready for this all terminals period are rated 75 degrees c period if that's true then i'm not i don't care about 110 14 c1a that says about 60 degrees c i don't care 1 10 14 c 1 a 2 which talks about you can use 90 degrees c wire but you got a size 60 degrees c i'm going 110 14 a1 a1 110 14 110 14 c1a3 that says that if the terminals are rated for 75 degrees c then you can size the conductors to 75 degrees c now that's a big deal let's see an example see if you have a 50 amp receptacle let's go back up here a 50 amp receptacle then you'd have to have six gauge wire let me go here a 50 amp receptor you'd have six gauge wire because you have to size 60 degrees c if you had 100 amp breaker you had to have one gauge wire because your size 60 degrees c but if i have equipment that's rated 75 degrees c i go to table 3 10 16 i go to the 75 degrees c column and since it's marked that way i'm going to size it it's going to be 8 gauge that's what i'm talking about and what size conductor would i take into the 100 amp circuit not one gauge i would have taken three gauge this is a big deal all terminals are rated for 75 degrees c how would you know that we'll just just look inside the instructions look inside the cup or the panel okay now we're not talking about the rating of the terminals see this equipment is rated for 75 degrees c even though you might look at the lugs and the lugs might say 90 degrees c that's irrelevant it's the rating of the equipment not the rating of the terminals and you'll see the same thing on a by the way guys by the way guys do me a favor landscape take a picture of the inside of a panel for me send it to mike at mycold.com that clearly shows the information on that panel because i don't have a picture here and also like let's say on a range receptacle and a dry receptacle or any receptacle um that's going to be rated let's say uh 30 amps or more look somewhere in there it's going to be printed right usually it's going to be printed on the metal of the range in a dryer so give me that information then i can show it right now all right it was over now we got another rule which doesn't really matter because we're sizing everything 75 degrees c but see if it goes over 100 amperes the terminals are automatically rated for 75 degrees c what's my point my point is this get your code book out highlight that there you go table 3 10 16. we set a tab this is a total waste of time don't give me guys time and on table 3 10 16 i'm not highlighting 75 degrees c and you know what i'm making out there i'm going to write this is what i do in my videos if you're watching my videos i'm going to write on that 75 degrees c 1 10. 14 c i'm going to do something on the 90 degree c column you got to make notes you got to customize your code book see later on you can find like where the heck was that okay this is so much fun guys i don't know about you guys i love this i love helping you guys all right here we go ready for this what about is 150 amp well guess what 110 14 c1 i highlighted on the table of 3 10 16 i made a reference where it's at so i can make sure i cover that and that would be 150 amps why not done slam let's go that's it that's how that works now based on that information everything that we do after that we have to remember now if you're taking a test this is something you got to be really careful of if you're taking a test and the circuit's 100 amps or less you have to hope that the guy who wrote the test knows that you size the conductors to 60 degrees c and if it's over 100 amp years you have to hope that that person knows the size of the 75. now what i do in my textbook is i'm not sure if that's a good idea i should do it or not i generally tell you the terminal ratings of the equipment but i think what i should do and i think i probably do this if it's 100 amps or less i don't say anything which means that you better know 110 14 c1 a one rule and if it's over 100 amperes i don't say anything either because what you better know 1 10 14 c 1 a 2. oh no a c what is that let's go back to the rule what was that over 100 amperes oh b i'm sorry within 14 b 2. hey by the way this is an interesting one i almost skipped this i almost missed this 110 14 c2 this has to do anytime you're terminating conductors not on equipment what's equipment well breakers equipment a panel board's equipment a disconnecting means is equipment a fusible disconnect is equipment but when you're terminating let's just say on a terminal block a power distribution block you're making splices okay everything like that is rated at least 90 degrees c probably at least 105 who cares if it's more than 90. that means guess what without me getting into the detail this conductor is terminating on terminals it's 100 amps or more i mean over 100 amps are what so you need the size of water seven let's say this 400 amps well 400 amps let's say we're going to use 500 casey mills and 240.4 being next size up okay but if it's 400 amperes okay this y right here i size that wire to 90 degrees c not 75 because why because that end of the conductor the wire's right at 90. this terminal is rated at least 90 probably 105. this other end over here that wire still is still rated at 90 degrees c and that term is still 90. so you can size those conductors between those two points which would be smaller than it would be the conductors the other end or the discussion i spent i spent a lot of time on my video explaining that in my textbook all right let's go on oh man we're running out of time brain circuit conductor size for continuous loads right this is complicated stuff i'm going to do it okay brand circuits by the way this applies the brand circuit this concept applies to brand circuits it applies to feeders and applies to services the same logical concept same thing brand circuits must be sized to carry the largest of one a or one b the largest of the two okay so let's find out what's number one a what's number one b and it has to comply with 1 10 14. what is 1 10 14 c that's 60 degrees c 75 degrees c 90 degrees c what we talked about on the terminals all right so number one 210 1981a says you have to size the wire at 125 percent of the continuous load plus the non-continuous load okay and in reality when we do that what the terminal ratings are the equipment let's say we're talking about what's the terminal ratings of that 75 in reality okay so let's just go to one a1 and by the way one a b says a hundred percent of the continue so we have 125 percent of the continuous is one choice and that's without any correction and adjustment and then it's a hundred percent of the continuous at the correction adjustment we didn't talk about correction adjustment yet that's it's in my books and the exam prep book really covers so basic rule is this 110 14 110 19 i'm sorry a1a says that you size the brand circuit conductors it could be applied to the feet is the server same thing no less than 125 percent of the continuous load plus the non-continuous all right so let's say it's a continuous load how do you know it's continuous mike well because the example said 44 amps continuous okay well that's the case then you have to size the branch circuit conductor a rule because it's a larger eight one a and one b so one a would say okay well then take the load at 125 percent come out to be 55 okay and i made a note here the terminals are rated 75 degrees c okay and that's the case then then i go to table 3 10 16 go to the 75 degrees c column for 55 amps six gates right okay six gates that's easy now watch what you're doing here your sizing is wired to 125 percent of the continuous load and then you're sizing it based upon 75 degrees c but in reality the wire is rated at 90 degrees c and it has a much higher ampacity so we're not even using that higher opacity in addition to that we're sized and wired 125 percent why is that i mean if you had a 20 amp wire i mean you have a 20 amp load wouldn't you think a 20 amp breaker you put a 20 amp wire no if you have a 20 amp continuous load you got a size 125 of 20 which gives you 25 which means you have to put a 10 gauge wire and then you'd have to put a minimum 25 amp breaker why just because the breakers are not designed to carry the load continuously can't get into those details it's in my books though all right so 44 times 1.25 60 55 amperes 6 gauge wire done that's 1 a 1b is saying listen after you apply opacity correction and adjustment then you size the wire to a hundred percent of the continuous load okay let's work an example this equipment is non-linear they talk about 2261 neutrals but the neutral conductor on a non-linear load is going to be a current carrying conductor and that's going to be 310. 310.15. they moved it from 7. i'm 3 10 15. i can't remember now it's not it did in 2020 code they they moved it slightly in there so it used to be b7 not not b7 b7 neutral i remember what it was all right since a neutral is considered current carrying load oh there's right there 310 15 c1 tells us that we make an adjustment for the number of conductors bundling and that's going to be 80 percent but we now use the 90 degree c column i'm highlighting my 90 degree c column now and this is going to be i've got to give you the code reference on that and here's the reference here that reference is 3 10.15 i feel like when i was learning my code book getting my co-book highlighting and tapping it 3 10 15 a 3 10 15 a says this the temperature correction and adjustment factors which we're making at adjustment shall be permitted to be applied to the opacity for the temperature rating of the conductor that means 90 degrees c wire so back to where you were okay so now the neutral is considered current carrying conductor let me get that reference that's going to be 3 10 that 15 e they changed it all the way to e 3 10 15 e so the neutral is considered a current carrying conductor i have four current carrying conductors i go over to the table the table there uh is going to be on page 157 no no that's not 157 it's going to be does it look good there's seven any further than that i hate it oh right up it's right there opposite from the opacity i highlight that four conductors eighty percent adjustment so then you do what you take your wired you picked on a and that was six gauge wire but you then go to the 90 degree c column because that's what 3 10 15 a says and then you adjust that opacity of 75 amps times 0.8 to 60 amperes and it has to have the opacity to be capable of carrying the load so a 44 amp wire is permitted on a 60 amp breaker now another way you could do it is simply take your load your load was what uh 50 44 amps and divided by 0.8 and they go to 90 degrees c column just to pick the wire so there's two ways you can do that it's kind of complicated stuff this is definitely exam prep stuff this is something in my series of things that you do you'd be covering this like after i think this is step four you'll be covering these things so a six gauge wire make the adjustment at 90 degrees c and that's it guys that's really complicated and i'm sure you have a lot of questions and i'm not gonna be able to answer them because you don't have enough experience to understand and i apologize so i'll do the best i can but or i can answer them but it might be like i don't understand what you just said so i don't want you getting frustrated about this this is something that is seriously covered both in my understanding nec but primarily conductor sizing and protection when you get into the exam prep this book is all calculations you know most of it is all calculations and that's when you get practice and practice in practice so this is very very high level stuff um and i had a question here's today mike guys what if the conductor has no indicated temperature rating on the insulation what do i do and i'm thinking what do you mean what are you doing i realize oh my gosh not everybody knows what the installation rating is so 310.4 which used to be 310.104 was relocated gives us information about insulation you need to know this t-h-n slash t h w n very standard conductor insulation t stands for thermoplastic double h just so you know if there's ever two h's that's 90 degrees c if there's a single h it's 75. if there's no h's then it's 60. tw 60 thw thwm 75 t-h-h-n-t-h or x-h-h-w 90 degrees c that's how you know what column to use now in addition if you go to table 310.4a you're going to get all that information so that's how you know what the insulation rating is so i'm not sure what i want to show here well here single h here's a double h the reason is a double h and a 75 is because it's a wet location wet locations are never more than 75 degrees c for conductor opacity purposes dash two here's t h w which is one h mike you said 75 yeah i know but it's a dash two what does that mean that means double h's well what does it don't let's not get in there okay that's just what they do so you know sometimes you get frustrated because you want things to be perfect listen you're not perfect okay i know you're not perfect and i know i'm not perfect so i'm not gonna sit there and complain about somebody else because they're not perfect and this is not an easy thing to do and these guys spend a lot of time making this code the best they can so all we got to do is this understand it when you see t h w n 2 you know it's what it's 90 degrees c if you see x h w you know it's what it's 75 degrees c because if you went to table 310.48 it'll give you all that information so this is like a shorthand but you got to understand the shorthand and it's not the bigger deal you just need practice you're going to do great i got this email this morning or this afternoon i thought it was interesting a little small text and you gotta have to read it brian before i jump off did it have anything you think that i can answer uh you know mike there was a lot of comments but i don't think it's anything that we can really reel in here you actually answered quite a few of the questions just kind of as you went through things people were asking questions and it works out really great it seems like if if i wait long enough you actually answer their questions they probably think i'm telling you the questions in your ear but i'm really not you just you seem to cover everything they need so it works out really well here's an email i got this afternoon i think it was this afternoon uh what time was it yeah 12 59. mike just looking at bonding and grounding video he says he i was just looking at a bonding or grounding video just brought just bought from you guys about 250.6 objectional current reminds me of when i worked as an electrical inspector in williamson north carolina when i was in the early 30s we were required to check all electrical installations for what our department called bonded neutrals that's where it might you bond the neutral and the subpam that kind of stuff my chief inspector told me that this was a wiring integrity rule 110.7 it's not but didn't understand it until i said but i didn't understand it until i watched one of your free videos on youtube channel chip channel on objection current while teaching a journeyman's class that was what we were really checking for and the grave importance of this explain to the students in class which all of them worked for electrical contractors and areas finally realized what the inspection department was really looking for and why so by him teaching this and why is it feeling like oh now i know what they want me to do checking for these were all the checking for these they always made us use at least when i worked there an analog meter when we also checked for cross neutrals which until i viewed your video on 277 120 cross neutrals really saw the importance of that thanks for the content of this video and if you have time on one of your webinars please bring this up bonding and grounding is so misunderstood and by many but in my opinion is the most important thing again okay well if you get my binding and grounding book i explain all this but if you go to michael.com i'm going to show you and you click on videos i get bad news for you guys taking a little while then you're going to see all my videos and you can go to bonding and grounding you can go to bonding and grounding okay and then you can go down to where there you go objectional current why am i taking my time to do this and that's the video you can see i have a friend of mine who is on my understanding unc 2 which is article 500 through 820 his name victor ammons he's been on my video team maybe as long as eric strongman if not very very close and he's he's an engineer like like eric i mean amazing people and he's involved in writing all the specifications you see all those international standards electrical specifications the engineers use he's the guy that's involved in writing that on the committee that's how smart this guy is and he knows code and he's an amazing guy he came to one of my videos and he was telling me that he lost a brother-in-law who's electrician on a job site and he didn't understand how the guy got killed because all he was doing was hooking up a transformer that the primary was turned off follow this the primary breaker is off on the transformer he's working on the transformer the guy got killed if you want to know why then you need to go to michael.com go back here then you need to go to the front page here and you're going to click on videos then you're going to go to bonding and grounding bonding right now grounding and bounding then you're going to go to objectionable current and you're going to watch that now this is a huge amount of theory on objectional current and how that works out so i don't have the time to get into objectional current because i don't need to because there's a video i don't know how much time that video is i i don't know if we have it if it tells us quickly there with only 29 minutes okay i don't have 29 minutes to get into it so please watch the videos that i already have on the website wow i got enough time all right the ampu rating of a receptacle in a 20 amp circuit mike doesn't the nec require 20 amp rated receptacle on a 20 amp circuit nope so if you have a 20 amp circuit you can put a 20 amp receptacle on it it makes totally no sense to me why anybody would use a 20 amp receptacle it would be the rarest case that you would ever put a 20 amp receptacle on a 20 amp circuit because it would make no sense i'll explain in a minute now 15 app receptacle makes sense well kind of me it makes sense well mike you're telling me you wouldn't put a 20 amp receptacle 20 amp circuit because it makes no sense yeah absolutely doesn't but you put a 15 amp reception on a 20 amp circuit that makes sense absolutely help me give me some information there okay let me give you information you take the cover plate off a 15 amp receptacle do you know what the inside construction 15 amp receptacle is it's a 20 amp receptacle it's a 20 amp receptacle 15 28 receptacles are exactly the same the only difference is when they go to the production line they plug in a 20 amp cover plate i mean a 20 amp whatever that plastic is going to be on that name column markup 28 faceplate thank you faceplates i don't know if it'd be a faceplate the face they plug in they just push in the 20 amp faces and then they they mark them as a 20 amp receptacle 125 volts and they charge a lot more money and then they run the the others they run the same configuration they just press the faces of the 15 amp receptacles do you ever wonder why you can buy a 15 amp receptacle and you can use it on a 20 amp circuit like a gfci feed through did you ever notice that you could put you could put wires on a receptacle i'll just use the word there's no such thing as line and load in reality in the code but on the line side of the receptacle bring in the power and then leave the load side and feed another receptacle kind of go line just keep going down the line and feed through the nickel because you're working on the screws i didn't have that problem one in my house i'm plugging in the back okay so some of you guys have a problem with that i don't care it's listed i haven't had a problem you have a problem then you do what you got to do so i would push it on the line side and i would on the load side push and then go down the line unless i had a problem then i would change my practice but it doesn't matter we're talking about 15 amp receptacles the internal construction is a 20 amp receptacle and watch this the code tells us this on table 210.21b3 that a 15 amp circuit you can use a 15 amp receptacle you can't put a 20 amp receptacle on a 15 amp circuit that's kind of interesting but a 20 amp circuit you could put a 15 or 20 amp receptacle but now this rule only applies under the condition so let's read the conditions we're connected to a branch circuits applying two or more receptacles or outlets receptacle rating shall conform to the table so if you have two or more receptacles then you could put 59 receptacles on a 20 amp circuit so what's two more receptacles well you've got article 100 definition what's a receptacle contact device installed at an outlet for the connection of an attachment plug i don't know if you notice that that's singular that's not plural or for the direct connect okay we're gonna stop right there so this right here the little guy right here micro with what that's a receptacle what is this right here ah another receptacle we call this what duplex receptacles what does that mean there's two what two receptacles now so you could have single receptacles and you could have then what multiple receptacles what did the rule say it says we're connected to a branch circuit supplying two or more receptacles is this considered two more receptacles in other words if i put a circuit which i didn't but if i put a 20 amp breaker and i went to one duplex receptacle only one duplex receptacle can that receptacle be 15 amp rated connected on a 20 amp circuit duplex receptacle is what two or more receptacles so hopefully and if you notice that mike why do you say you don't think it makes any sense on a 20 amp receptacle on a 20 amp circuit listen guys how many times have you plugged something in in your lifetime that it would not plug into a 15 amp receptacle if you're a manufacturer of equipment you're going to make sure all your attachment plugs on the equipment are rated what 15 amps that way they can plug in anywhere they want to because if you make it a 20 amp like an air conditioner and you need more than 12 amps worth of current capacity in that piece of equipment well then you're going to put a 20 amp attachment cord that will only plug in i'm going to take that would only plug in to a 20 amp receptacle so the only time you need the the t slot right here receptacle is when you're plugging something in it it can only be plugged in it because it's going to be slotted does that make sense so you'll see almost all commercial receptacles in a building are rated 20 amps and guess what they're paying a lot more money than if they just put 15 amp receptacles in there and that's the reason why brian any any questions a lot of comments uh some of the guys are asking about i'm gonna i'm gonna try to pull this off then all right i'm gonna try to hit one more thing go for it all right all right let me give you the bad news guys i woke up at 4 4 50 this morning and i whenever i do these live streams you know understand i'm a wreck all day long trust me i mean i'm a total complete wreck and i mean i'm thinking i'm studying getting graphics i'm doing everything i'm sick to my stomach i i've gotten better it's not as bad as it was because i'm more comfortable with the equipment when i not having problems inside here um i just woke up i thought god tell me you're done with the videos time to spend some time with your wife time to get some other work done so i'm finishing up tonight's video in the next five minutes i'm doing next tuesday and then on wednesday i'm covering um how to transition your life how to go from a helper to a journeyman a journeyman to a foreman former to a project manager maybe moving into the office of a business maybe becoming an inspector getting your certifications maybe becoming an instructor maybe going into business of your own so all these difficult transitions that's what i'm covering next wednesday and then on thursday i'm covering the final day of technical brian is going to do some things after that power over ethernet p-o-e and probably some other things having to do with instructors and and curriculum and things like that so i'm gonna be done next friday next thursday and i'm taking off friday morning with my wife on an rv but i love you guys and i love doing this and i'm going to really miss it a lot so here's the deal i'm no longer officially going to have this schedule but i know brian and i are going to be hey brian how about tomorrow night we'll go ahead and do something because okay you get it ready to go i'll get it all together on it because brown handles all the equipment and i just come in here with the pretty face and with all the technical stuff and you know and kill myself you know i mean getting it ready for you guys so tuesday and thursday technical next week wednesday transitions how do you what do you do with your life and then after that it's just going to be random events that you guys will know about it because uh you register at michael.com live and if you do that i'll automatically be notified and you'll know what's going on all right brian anybody any comments you want to say because i'm we're going to close it up i'm not going to i'm going to be talking about bonding of snap switches but it's i don't want to rush it yeah we we've had a lot of comments guys and and here's what i'll tell you some people asking about the internal construction of receptacles uh i grew up in the trade and i was electrical contractor and if you haven't taken the time to take some old junk you pulled out of a job and take it home and take it apart i would highly recommend that you do that because uh it doesn't matter what we say here what you try to google you know and and michael say this i know mike you took apart like probably the first afci receptacle ever made in the entire country oh yeah the second you got it you know but take this stuff home take it apart understand how it works we've got a lot of great pictures in our books also that just kind of cover some of that stuff but you know serve yourself well educate yourself don't just rely on other people to give you information that you carry around with you hey guys hold on 210 21b3 says you can put a 15 amp receptacle on a 20 amp circuit there has to be some logic on that okay if you notice gfcis are all to my knowledge i don't know if they make a 20 amp slot at gfci maybe they do but more than likely if they do it they don't you put a 15 amp gfci receptacle on all dwelling units and you need 20 amp circuits to dwell on you to bathrooms you need 20 amp circuits to dwell on the kitchen countertops you need 20 amp circuits for laundry rooms you need 20 amp circuits for garages and all of those areas require gfci so if you go anywhere in the internet says that i'm full of bs then you need to make sure you don't ever watch that website again because they don't know what the heck they're talking about there's a logical reason why you can put a 15 amp receptor on a 20 amp circuit and why 15 amp receptacles are rated for 20 amp feed through take a look at the instructions they're 20 amp feed through it's just a 15 amp face or guess what prove me wrong get a hold of a manufacturer who says that the internal construction of a 20 amp receptacle capacity wise is that it has a greater amount of copper and that's why it can carry 20 amps and a 15 amp has less copper i don't think so all right guys i'll see you tuesday or the next recording [Music] ciao you

Channel: MikeHoltNEC

Views: 57,233

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Id: -UyOYK0krko

Length: 60min 33sec (3633 seconds)

Published: Thu May 21 2020