The sizing of conductors primarily, is dictated in section. So if you're looking at your NEC code and by the way you can, you can look up the NEC for free on NFPA or for slash free access, they make it a little tricky. So you got to go down to n SP, seven and at PA. Seventy, which is the National Electrical Code, pick the whatever version you're looking at and then you can pull up a free version.

You have to sign in and you can't copy anything. But you can at least reference the code, and so if you want to look this up for yourself, it's three ten period nor dot I'll just say dot, three 10.15 be sixteen. So if you look up that, that's actually a table and that table it formerly was known by three 10.16, I'm looking at the twenty seventeen code, which is largely not even in it's, not even in use in most places, most places are still using the twenty fourteen Code and so I'm using the twenty seventeen code so that we're prepared for the future, basically here just making sure that there's no questions about what particular version of the code I'm looking at and also just so, you don't get bored here, there's a reason why I'm Doing this as a reason, why I'm pointing to the specifics? Because I don't point to the specifics: if you've had in your head, that it works a different way, then you're going to want to think that I haven't done the research on this. But I want to just illustrate here briefly that the research has been done and I'm not saying that I'm immune from making mistakes in this.

But I'm going to try to stick to the very basics, the stuff that really matters and not get to off into the weeds, and so most of what I'm saying here should be pretty ironclad. So if you go to three 10.15 be sixteen, this gives you the actual temperature rating of different conductors and the sizes the impasse --'t is, that can be. They can be run on those, so the amperage that can be run on these conductors. So as an example, if you look at will use common, we'll look at number 10 wire, so number 10 wire at 60 degree Celsius, which is 140 degrees.

Fahrenheit insulation rating on a wire is rated at 30 amps. So that's what we typically hear. We hear number 10 is 30 amps period right. Well, not quite because when you go to 75 degrees Celsius, which is 167 degree insulation rating, it's rated for 35 amps, that's actually the more common type of wire.

That's used, that's th, h, WT, HH n are in that are in that rating and actually some of them some th, h, NS and th h. Ws are actually rated at a higher rating than that. But that's what you're going to see commonly this is copper conductors. So some th H, n wire, is actually rated at 90 degree Celsius and some of this again I don't not regularly looking at the wire that that we have on our truck as far as temperature rating.

But if you want to grab a roll of wire off the truck or look at one, an electrical supply house and you'll see these ratings listed on there. And so the question is: why do we often say that it's so-so just to just to clarify so number 10 wire at 60 degree, celcius insulation, it's 30 at 75 degrees, 35 and a 90 degree it's 40, but we often say that it's 30. Well, the reason why we often say that is because we're often talking about nm cable, which is nonmetallic, cable, otherwise known as you know, the trade name would be ro max for that, and so this is the typical wiring. That's used in a lot of modern houses and nm has to be the ampacity have to stick with 60 degree Celsius.

As far as the the overall capacity there's some D rating and things, you can do at the 75 degree level and I'm not going to go into that. But the basic residential wiring in a normal house for the lights and outlets in your house with nm, which is Rho max, is rated at 30 30 amps for number 10 wire, 40 amps for number 8, 55 for number 6, so on and so forth. So that's typically what we think of, but if you look at so, for example, number 6, we think of 55. What number 6 is actually 65 at the 75 degrees Celsius, thh n, th, HW many either 75 or 90 degrees Celsius.

There are certain types of wire certain types of assemblies that can be rated at higher amperages than what we're used to saying in our sort of rule of thumb, minimums that we that we speak of, and - and so it really just depends on the application, if you're Using Roe Max and you're running it to the condenser, well, there's a problem there right away because romex isn't rated to go inside of, say a car flex whip or something like that. It's not it's not rated for that! It can't go into what they call a damp environment and a condenser is a damp environment. It's running outside of the structure, and so in that damp environment you're not supposed to have nm anyway. So if you're using you know thh W, for example, that's rated at 75 degrees Celsius, then that that 30 amp breaker is okay to be at 35 amps.

So and I'm going to go into some more because there are some more considerations, I'm going to go into that, but I want to stop here. So this is something that's independent of the whole question of putting a larger breaker than the ampacity of the wire. That's it that's the next thing we're going into, but this is an independent thing, which is that often what we think a wire is rated at is not what the wire is write to that and it can go either direction. So we can be.

We can go on the over conservative side, where we believe a wire is not large enough when it actually, indeed, is large enough. If you look at the insulation rating on the wire or we could be grossly under sizing a wire, because we don't understand all of the de-rating factors or the type of wire that it is or we could be using Rho Max and M cable in a place That it's not rated for and so there's all these different considerations, and often we in the field we can. We can be on both sides of the coin, where we don't understand either of them, and we just think it's number 10 wire is 30 amps, but it just it just isn't quite that simple.