Awl--
Just got off the phone with phase-a-matic, who charge way too much for their rotaries, but are nice people, helpful.
They sell a voltage *stabilizer*, $339 for the 5 hp, 579 for the 10. Guarantee it to less than 5%. Don't know what a stabilizer is, or if you could kluge one, but the rcm peeple proly know.
If your line is connected to T1, T2, and the wild leg is T3, the caps are actually connected between T3 and either T1 or T2. You can arrange to disconnect these caps after startup, but Phaseamatic says this won't really help the voltage problem, altho the rcm people say tweaking caps can help, altho I don't know the details. Mebbe caps T3 to ground, *after* the unit is running?
I think Sam here has recommended disconnecting the caps after startup, easy to do with a relay--relay coil from T3 to ground, if 120, T3 to either T2 or T1 if 220, NC contacts. Should extend the life of the caps.
Another way to help the wild leg is before running cnc off the wild leg, run
*another* 3 ph motor off the rotary, as a kind of idle load--which also gives you more 3 ph capacity!--which then drops the 3rd leg better--verified by phaseamatic. If this is so, then a 120 V load just off the 3rd leg should help as well.A lot of 3 ph motors together act as a kind of "rotary Borg", so that if they themselves aren't too heavily loaded, other 3 ph motors can draw from this "grid". Neat, eh?? Thus, a shop does not necessarily need a giganto rotary, just "step in" smaller motors in sequence, to build yer Borg.
I have this kind of set up in my "converter" station, as, bein a 1 dude hack shop, I would have to turn on whole machines with no one using them to create this 3 ph grid. And, I don't have *that* many 3 ph machines.
The best way is to see if the electronics can be directed to legs 1 and 2, which is just yer 220/240 single phase. Then much of this is moot.
Others sell voltaage stabiliziers of sorts. Steelman (Kilgore, TX) at 903
984 3061 makes a nice rotary and a regulator (I have their rotary), and phaseamatic is at 661-947-8485. I have one of these also.Phaseamatic rotaries run HOT, yo. They said this is normal! They use a Baldor motor, specially wound for them, but I never heard of a motor designed to run hot!! OVER 200 deg!!! Sheeit, bring yer marshmallows.... The Steelman H-A-S runs nice and cool.