Interesting question ... again. ;-) Does voltage drop figure in here? Are you going for the minimum that is legal (2 ga with 125 O/C) or what would give better reliability (1 ga and 150) both using 240.4(B). I would want to use staggered timeouts on the compressor time delays so you wouldn't have 3 liquid slugged compressors in locked rotor at the same time on a power hit.
Re: A/C Feeder#94736 08/11/0508:53 AM08/11/0508:53 AM
Some would say #1 and it probably would be a better design choice for the reasons you stated. Some inspectors maintain that you add an extra 25% of the largest motor. Some inspectors will take the largest motor of an individual A/C unit and add up all the other motors and come up with a smaller conductor yet.
I think we already covered that ground last time. Some might even argue that the 125% thing has been done 3 times in that engineered number on the HVAC label. If the run is not excessive the #2 should be OK. The only caveat I would have is staggering the time out relays and that is really a design issue.