Feeder conductor sizing using Service conductors

[2Broke2Sleep]

I am looking for the NEC article that states feeders do not have to be larger than the service conductors they are fed from. I was under the impression for the longest time, say you've got a single family dwelling, 200 amp service, you run 2/0 to the meter, and 2/0 to the disconnect. I always thought from the load side of the service disconnect you had to size your conductors 3/0 because they are now classified as feeders so they can't fall under the 83% rule anymore. Someone brought it to my attention that you can in fact use 2/0 for this situation, that is, load side of service disconnect to say, interior MLO panelboard... Can't find the article they cited, and it always worries me anytime im sizing a wire pull that I'm going to get flagged by an inspection for the wrong wire size and look like an idiot, and have to eat the cost of it all.
Would like to put my mind at ease once and for all.

 

[don_resqcapt19]

310.12(B) and (C) in the 2020 and 23, 310.15(B)(7)(2) and (3) in the 2017

 

[2Broke2Sleep]

310.12(B) and (C) in the 2020 and 23, 310.15(B)(7)(2) and (3) in the 2017

Bingo! It's a dwelling unit rule, got it

 

[don_resqcapt19]

Bingo! It's a dwelling unit rule, got it

Yes, because dwelling units are the only place you can use reduced size service conductors. Everywhere else the standard conductor size and overcurrent protection rules apply.