OK, here are the results of connecting 104uF caps between legs A-B & B-C on
the output of the idler motor.

At the motor A-C = 238V
A-B = 255V
B-C = 218V
(B is the 'wild" leg

At the transformer output H-1-H-2 = 493V
H-1-H-3 = 501V
H-2-H-3 = 517V
The taps on the transformer are set as low as they go.


--
Peace
Milo
http://s235.photobucket.com/albums/ee67/mholroyd/
"Milo" milo@oil filter.hughes.net wrote in message
...
"RoyJ" wrote in message
...
Heh!! an unconventional way of drawing it but perfectly clear.

With the pony motor you don't need to worry about starting. Just put a
run cap from each 220 leg to the wild leg. Iggy had some values for the
caps, good place to start.

Here's a good place to start for the necessary caps.
http://www.surpluscenter.com/sort.asp?keyword=EMRC

Thanks for the help. I'll post back here as soon as get some caps.

Peace
Milo
http://s235.photobucket.com/albums/ee67/mholroyd/








Milo wrote:
"Joseph Gwinn" wrote in message
...
In article ,
"Milo" milo@oil filter.hughes.net wrote:

I read a lot of write ups on using capacitors to balance the 3PH out
of a
idler motor.
But, I can't find anything on using them with a 440V system.

Brief description of my set-up: (what I'm trying to run is a 5HP 440V
lathe
motor 2 speed, reversible)

I have a 110V 1PH 1.5HP pony motor, belted to a 230V 3PH 7.5HP idler
motor.
Feeding the idler motor with 220V 1PH on A & C leg, wild leg on B. A B
& C
feed into a 440/208 auto transformer 'backwards' to boost the voltage.

I'm having a hell-uv-a time dialing in my 440V. I have multi taps on
the
transformer, but try as I might. I just can't get 3 legs of 440. I can
get
two, but as soon as I try to dial in the wild leg, (using the taps)
one of
the other legs goes high or low.
If I understand the description, the autotransformer is three phase.
If
so, one can the treat autotransformer and motor as a unit, and apply
the
balancing capacitors to the idler motor as if it were connected to a
220
volt 3 phase motor. Varying the taps on the autotransformer doesn't
sound right.

A wiring diagram would be useful.

Joe Gwinn

This is not professional, but should be helpful.
I don't know if pics are allowed here. So here is a link.
http://s235.photobucket.com/albums/e...urrent=RPC.jpg

Peace
Milo
http://s235.photobucket.com/albums/ee67/mholroyd/