Multi family dwelling Service

[AspenElectric]

Hi, All.

I’m having a little trouble sizing a two family dwelling unit service. I have two 150 Amp main breaker panels. The service is currently 200 Amps (100 per side). I am looking to upgrade all of the exterior to support my two 150A panels, so basically a 300 amp service.

Can I shoot straight to the table in 310.12? What if I wanted to parallel the service entrance conductors?

I’m coming up with needing 250 Copper, or 350 Aluminum. 3” riser.

What wire type do I use in a rigid riser? We have always used URD but I’m sure that isn’t totally correct.

Any insight or guidance would be greatly appreciated.

 

[infinity]

Since you have two meters your service conductors can be sized for the calculated load which may be less than 300 amps. If you want to go with the full 300 amps parallel #1/0 in two raceways would work. If in a single raceway derating would need to be applied.

 

[AspenElectric]

Since you have two meters your service conductors can be sized for the calculated load which may be less than 300 amps. If you want to go with the full 300 amps parallel #1/0 in two raceways would work. If in a single raceway derating would need to be applied.

Can I not do aluminum 350’s in a single 3” rigid riser? Or copper 250’s? That’s what 310.12 shows.