"Wild_Bill" wrote in message
...
I trust you are correct, Bill. Perhaps a better choice for a word to
replace (the) *purpose*, would be (the) advantage
... of the capacitor in the motor's starting circuit is to increase
torque during startup

--
WB
.........

close, but still not quite right - for example, take an old time clock motor
(really old time - like 1930) - many of these will run either way and there
is a little knob to twist to start them in the right way - if you do
nothing, they sit there and buzzzzzzz. spin the knob and off they go. So,
the start windings on your larger motor are like this little knob - they
produce a rotating magnetic field, like a 3 phase motor. To do this, you
need to get the phase angles, and that is where the capacitor comes in. It
forms an LC (inductance/capacitance) circuit with the coil and that creates
the phase shift.

So, yes, the start winding increases torque, and the capacitor gives the
phase shift so it will turn and in the right direction