Hiking said:
Hello all,
We have a motor which can be hooked up either in Y configuration, or
Delta configuration. Which configuration will give more start torque,
and then the most operational torque, and why in each case?
...
Never mind guys, I wasn't so much concerned with which configuration to
connect for its own sake, the boys here will do trial-and-error and will
wire it from there. The guys here don't care why. For myself, I was
only interested in the "why", in understanding the "why"s of this situation.
I remember from school many, many years ago that torque was a result of
the phase differential between the outer winding (what do you call this
one again?) and the induced EMF in the armature, the greater the
difference, the more torque you get. As the armature gains speed and
nears synchronization with the rotating EMF in the outer core, the
torque is reduced conversely. I understand the EMF in the outer core is
not really "rotating", but the effect is of a rotating field... and if I
understand this correctly, by increasing the frequency of the outer-core
field, one could increase the operational speed of the armature,
correct? I suspect, however, that this higher frequency would also
result in a reduced starting torque capability for the same motor?
But this is in a Squirrel Cage, single-phase induction motor, I have no
idea what the situation is with a 3-phase motor... I expect it's the
same operational principle, only difference being that there are three
outer-core windings.
What I was really hoping to understand is how these dynamics are
different with these two different wiring configuration.
If anyone can explain what happens in this motor/system under these two
varying configurations, and has the time and desire to explain it, I am
all ears and appreciative.
Can you guess I drove my elect teacher nuts? I have to hand it to him,
however, he was extremely knowledgeable about the internal, theoretical
method of operation of elect motors... good 'ol Mr. O'Brien. Though he
seemed to think it was a waste of time for me to understand elect theory
to this level, he did humour me and I did understand a lot of it and it
still is a big help... the problem being that as soon as I learned it, I
ended up going into another field of work and never used/applied, nor
thought of electricity since, for over 12 years, so, unfortunately,
forgot a lot, and am just trying to refresh my memory.
If you're in a teaching mood, I'd love to learn/understand this subject
a whole lot better. Thanks.