Situation: Home plus agricultural building, current service is 200 amp.

The service line comes into a central point which is a generator shed (that's where the meter is). There is currently a 200 amp disconnect at the shed. Originally, the 200 amp was to feed both the house and the pole barn but now it is desired to upgrade to 300 amp service so the pole barn can have it's own 100 amp capacity leaving the full 200 amps for the home.

Can I just add a second 100 amp disconnect switch for the separate pole barn, or must I purchase a 300 amp disconnect so both buildings can be disconnected with a single switch? I realize a new meter socket will be necessary. I can't find anything specific in the code, but it may be inferred by a few sections.

Thanks!