Greg, the way it works is that the Poco has residential wire crews and commercial wire crews.
The residential trucks are stocked with one wire size, period.
Poco's do not take 400A Services as a true indication of load.
First off, they consider them 320A Services -- for load calculations -- at the worst.
But, in most situations, the heavy-up occurred because the home went over 160A -- and calculates out to, say 210A.
For such a Service drop, the Poco is still going to use the same conductors. If the meter readings establish that the true load is way high, then the Poco m a y bump conductors.
But, they don't stock the next size up. That would be a special order. 350kCMIL is the next size bump. (Actually, a 336kCMIL is the Poco favorite.) The intermediate sizes are simply not stocked.
Pocos are not in the feeder conductor warehousing business.
