Sizing overhead free air conductors

[mta820]

I am installing 200amp single phase meter main in a field and its fed overhead from that i am going overhead to mobile home and under it to panel. I am putting 4/0 URD in riser and 4\0 URD with #4 AL for egc back out. Am i correct in using 310.15 (B) (20) for sizing the span between the 2 poles. Will be using a feeder plex with messenger. 3 insulated 1 bare for egc and messenger. this table says 4|0 al for 224 amps in free air? It is a residential application and this seems to be very large for being in open air. Am i missing something? I know the power company has #4 Al coming into this but there basing there wire size on load not overcurrent device like we have to. Just wondering if i am missing something?

Thanks

 

[GoldDigger]

Can you use the sizing rule/table for feeder carrying entire residential load?
If the load calc allows it you could also just use a smaller main breaker. It does not have to match the service. (Unless you get an inspector who applies "what if...." family of corrections to the NEC.)

 

[suemarkp]

Is triplex/quadplex really considered conductors in free air? This seems more like a bundled cable to me. I thought open air conductors were individual (like the POCO ones on the utility pole).