I thought Golf Junkie answered this perfectly.
1) (mostly likely) the engineer would stick with his original decision for the 350.
2) (not as likely) They might accept the 300 and ask for a deduct.
What am I missing, what other options are there.
Sorry if I sound harsh here, but what business is it of yours what size wire is specified?
The majority of jobs I work specify wires larger than necessary.
How about 350 Kcmils for 225 amp feeders less than 100' long?
We have done that, and we did not care why.
We install what we bid, or we ask for a change and get one of the results GJ has posted.
Bob
