Wire sizing beyond Main Service Disconnect

[csoc64]

When installing a 200A meter/main, am I correct in that the conductors on the load side of the MCB (service disconnect) cannot be sized as service conductors (4/0 AL) and must be sized as branch circuit conductors (250MCM @ 75 degree rating)? I have now seen multiple examples of 4/0 SER being installed on the load side of the MCB and am wondering if I am overlooking something.

 

[Dsg319]

Is this a dwelling?

 

[LarryFine]

When installing a 200A meter/main, am I correct in that the conductors on the load side of the MCB (service disconnect) cannot be sized as service conductors (4/0 AL) and must be sized as branch circuit conductors (250MCM @ 75 degree rating)?

Negatory, morning glory. The feeder conductors need not be larger than the service conductors.

 

[csoc64]

It is not a dwelling.

 

[infinity]

#4/0 Al is rated for 180 amps next size up rule 200 amp OCPD permitted as long as the calculated load is 180 amps or less.

 

[electrofelon]

There is no fundamental difference in conductor sizing and OCPD selection for service conductors, feeders, and Branch circuits.