How do you convince a customer that the civil engineer (not electrical engineer) that they paid to draw this print is costing them unnecessary money? How do you convince the engineer that you don't need to ignore all the testing laboratories findings as far as protecting wires are concerned by oversizing everything by more than 25% ?
I tried to explain to him that there is no danger in running 400 Amp wire for a service that is rated for 400 Amps and protected at 400 Amps, but got the "That's how I do it" response.
you don't.
there are a number of ways this can turn out that i'm aware of, and most of them don't benefit you.
you have no idea what relationship the owner and the engineer have, do you? it could be his
brother in law, y'know? or his drinking buddy, or whatever.
driving a wedge between a client and a engineer will turn out exactly as well as it would
if you found the engineer was telling the customer that your work sucked. what would you do
if the tables were turned?
you questioned the engineer, and got back a "duly noted".
you have a wet ink signature from a PE on a set of plans. bid it, put it in, and go to the bank.
you can RFI it by email, and get back something from him. then he owns it, and your due
diligence is done, but even that won't go well. it's more expensive this way, but not substandard
or unsafe in any way, and the signed prints absolve you in any case.
in my not so humble opinion pushing on this will blow it up in your face.