breaker/plug calculations

[nasti57]

Good afternoon , I am reviewing a distribution board with a 2000 amp circuit breaker ( 75 d ) within a 1600 amp plug. Do I size the conductors for the circuit breaker or the plug?

 

[augie47]

For the plug per 240.6

 

[Knightryder12]

I would add a spare conduit so at a future time if they need to upgrade to the full 2000 amps it would be easy.