[AT] More On Electric Motors

[Sheppard, Charles E]

I agree with the comments about the older motors being better.  Not only
did they have a higher Service Factor, but they were heavier, e.g. cast
iron instead of die-cast aluminum.  I have several old 1 hp. motors that
are bad because the centrifugal switch that disengages the starting
windings failed.  Somewhere I remember reading about a relay that can
start a single phase motor.  I think they were used on older
refrigeration compressors.  I suspect they engage the START winding for
a few seconds to get the rotor turning.  Anybody know about these and
where I might be able to get them?

 

On the discussion recently about three-phase motors:  I have seen many
articles about making a rotary converter from an old three phase motor
that "idles" in the circuit.  There are several ways to get this motor
turning initially like a single phase motor that can be disconnected.
The idler motor must be at least equal to the largest motor intended for
use (I think).  My question:  Can power be extracted from the three
phase idler motor?  The static converters use some sort of capacitors to
make a three phase motor run so it seems possible that you could use
capacitors to get the idler motor going and use it to power something
while serving as a rotary converter, too.