Sizing feeders for duplex

[Dansos]

Good morning All!!

I’m getting ready to install a 3 pos (200A ea) meter stack and we’re trying to figure out feeder size. (Meters will be for Unit 1, Unit 2 and LL)

Im planning to run 400AL x 2 for feeders.
(Used table 312.10 to figure out)

IF I was to use Art 220 and do a load calc, would THOSE figures be used to size the feeders using 312.10?

I guess I’m just asking if a load calculation would OVER RULE everything else and we’ll be allowed to run whatever size wire we calculate or is there something I’m missing here?

Just an FYI, the land lord panel will only be used for a camera system and a space heater in the basement. No common lighting (other than basement) BUT I understand that our calcs will only be applicable to this current situation and someone may come in the future all load stuff up. Is that something to worry about (from a code perspective) or do we not worry about future stuff like that?

 

[LarryFine]

IF I was to use Art 220 and do a load calc, would THOSE figures be used to size the feeders using 312.10?

I guess I’m just asking if a load calculation would OVER RULE everything else and we’ll be allowed to run whatever size wire we calculate or is there something I’m missing here?

It's that simple.

 

[infinity]

Im planning to run 400AL x 2 for feeders.
(Used table 312.10 to figure out)

Are these the service conductors or feeders?

 

[augie47]

312.10 can be used for the individual residences but not for a common service or the LL panel.
As the "meter stack" meters only or meters + overcurrent protection ? (as infinity asked)

 

[Dansos]

Are these the service conductors or feeders?

These are service conductors. The meter stack will have main breakers inside it.

 

[Dansos]

312.10 can be used for the individual residences but not for a common service or the LL panel.
As the "meter stack" meters only or meters + overcurrent protection ? (as infinity asked)

Meter + breakers

 

[augie47]

For service conductors feeding a 3 stack meter/combo you would size them to your Art 220 load using 310.16 ampacities.

 

[Dansos]

For service conductors feeding a 3 stack meter/combo you would size them to your Art 220 load using 310.16 ampacities.

Thank you for the clarification!

 

[infinity]

For service conductors feeding a 3 stack meter/combo you would size them to your Art 220 load using 310.16 ampacities.

This.