Just to answer a few of the above posts, I'm fusing at 70 A based on rounding up according to 240.4(B), using 75 deg terminations. Did not know about the new code change in 2005 regarding following 250.122 with the neutral. I will size it up to a #8(50A), and stay with #6 for my hots.
With all three motors on, it is 35A (@240V), that's using table 430.148, actual FLA is a little bit less due to high eff motors, however the biggest (3 HP) is just for jets and thus a non-continuous load. I am a little worried about inrush, however the pool controller will not turn all 3 on at once, so some stagger should alleviate that, they are running from #12's right now, and seem to work. This could be a heavily loaded feeder with everything on (hopefully rare).
I was thinking of upsizing to 2 #4, 1 #6, 1 #8, 2 #14 but I think the pull would be just too much (1" Sch 80, ~360 deg of bends). The math says it just barely fits in the pipe...it would be a beastly pull to be sure!
'd build it a lot bigger if I could start from scratch, but all of this 1" PVC is under a pool apron that's not getting ripped up. I am look in to reducing the HP on 2 of the pumps, or a higher efficiency. What else can I do?
