Mark Main wrote:
Why are you looking for an 8 or 16 pole idler motor?

My goal is to have 20 HP available and so I sized my idle motor at 2
times that; and it appeared from my reading that more poles would have
the advantage of easier start and slightly improved stability for the
3-phase power. If I'm wrong let me know. My hope is that 8 or 16
poles on a 40 HP will make starting difficulty closer to a 10 or 15 HP
2 or 4 poles.

It may be possible to start a 10 HP, or so, idler with capacitors but I think starting a 40 HP motor with capacitors alone is out of the question. Someone on RCM a while back said he was starting a 15 HP idler with no problems.

Yeah, I'll probably have to go with the pony motor. If I can actually
find a 16 pole motor then it will be interesting to play with it to see
if I can get it going with larger capacitors. I'd like to avoid the
pony motor if possible...I can be stubborn when I have a goal in mind.
g probably a trait shared by many who play with metals.

I've used a 30 HP RPC for years, and always started it on just the
capacitors. It was a 4 pole (1750 rpm) motor. It was fed from a 240V
100 amp panel. No problems for me.
I don't see why you need anything more than a 4 pole motor. Unless you
have a big grudge against your wallet.
No pony motor, Just about 2000 MFD to start. THUMP!. Running. Cut
metal.
Pete