Hey, Don, it sounds like you are beginning to go off half cocked, sort of
"Iggy style".

Do this: Visualize 2 deltas connected in "parallel" if you will..
Obviously the current paths through the branches, where the lines are
connected, are in parallel. Now look at the common point where the other 2
legs of both deltas connect together. Those points are no more in parallel
than they would be if they were between two wyes.

It may be helpful to look at the configuration in its wye equivalent. Same
thing. All this speaks to the very complex current flow in an idler and
load connected as a RPC. Two 3-phase induction motors running on the same
3-phase line do not constitute a RPC. A RPC is two 3-phase induction motors
running on single-phase current. Capacitor augmentation assists in tuning
the network such that it appears to be operating from a 3-phase line.

Bob Swinney



"Don Foreman" wrote in message
...
On Wed, 4 Jan 2006 00:12:38 -0600, "Robert Swinney"
wrote:

Don Young sez:

"Since the running idler and load motors are directly connected in
parallel
. . ."

You are right about there being "many ways to understand and describe how
things work" but the concept of an idler and load motor's respective
windings being in parallel is not one of them.

Bob Swinney

Hey, Bob, what about delta-wound motors? Sure looks parallel to me!

On Wed, 4 Jan 2006 11:42:34 -0600, "Robert Swinney"
wrote:

Hey, Don, it sounds like you are beginning to go off half cocked, sort of
"Iggy style".


Look at
http://users.goldengate.net/~dforeman/delta_3D/

Colored lines are windings, white lines are connections.
'Splain to me how the windings of same colors are not in parallel...

Don "Half-cocked" Foreman

Sorry, Don. We were discussing RPC's and I assumed (we know what that does)
you were thinking of RPC's as well. Two 3-phase induction motors connected
as a RPC are not, repeat are not in parallel. I'm afraid you have jumped to
the conclusion that two 3-phase induction motors connected in RPC fashion
are merely connected in parallel. That is not the case. See a later post
in which I tried to explain the defference.

Bob (if it sounds like Iggy, it might be Iggy, No! it can't be) Swinney

"Don Foreman" wrote in message
news
On Wed, 4 Jan 2006 11:42:34 -0600, "Robert Swinney"
wrote:

Hey, Don, it sounds like you are beginning to go off half cocked, sort of
"Iggy style".


Look at
http://users.goldengate.net/~dforeman/delta_3D/

Colored lines are windings, white lines are connections.
'Splain to me how the windings of same colors are not in parallel...

Don "Half-cocked" Foreman

On Wed, 4 Jan 2006 13:00:58 -0600, "Robert Swinney"
wrote:

Sorry, Don. We were discussing RPC's and I assumed (we know what that does)
you were thinking of RPC's as well. Two 3-phase induction motors connected
as a RPC are not, repeat are not in parallel. I'm afraid you have jumped to
the conclusion that two 3-phase induction motors connected in RPC fashion
are merely connected in parallel. That is not the case.

Mine is! Works fine.

On Wed, 4 Jan 2006 13:00:58 -0600, "Robert Swinney"
wrote:

Sorry, Don. We were discussing RPC's and I assumed (we know what that does)
you were thinking of RPC's as well. Two 3-phase induction motors connected
as a RPC are not, repeat are not in parallel. I'm afraid you have jumped to
the conclusion that two 3-phase induction motors connected in RPC fashion
are merely connected in parallel. That is not the case.

Hanrahan seems to think it is the case. The presence of the
capacitors notwithstanding, his motors are connected in parallel.

http://www.metalwebnews.com/howto/ph-conv/fig1.html