That is possible in a simple circuit but the variable-frequency drives
(which do try to maintain constant speed) are very sophisticated and will
sense such a condition and shut-down well before the motor would cook. This
is probably built-into the circuit to protect the drive electronics more
than the motor since they would be more likely to blow first. Also, while
Noble is correct about the start windings in single-phase motors, in the AC
variable-frequency case the power supplied from the VF converter is 3-phase
so there is no start winding to my knowledge.
Billh

"George" george@least wrote in message
...
Not owning one, merely drooling, does it try to maintain a constant speed
under load? I which case, might it increase and hold its current draw
past
the time tolerance of the breaker?

"william_b_noble" wrote in message
s.com...
one correction to Henry's remarks - low voltage, caused by excessive
drop
in
the feed lines for example, can in fact cause a motor to burn out,
especially if it drops the speed low enough that the centrifugal switch
engages the starting windings. However, I agree that you don't need to
worry about it.


"Henry St.Pierre" wrote in message
. 97.132...
Owen Lowe wrote in newsnlnlowe-
:

In article ,
(Ron E.) wrote:

Question 1: Talked to a PM tech who said my 20 amp service isn't
enough. Have to have minimum 25 amp, preferably 30 amp. Told him
that my 3hp tablesaw ran fine on this sevice, and he indicated I
was
lucky I hadn't burned out the motor. An electrician friend says 20
amp is plenty. What do you say?

Ron,
The PM tech may know PM lathes, but he doesn't understand electricity
that
well. Motors may burn out on a circuit that can supply too much
current
if
the motor has a problem (bind, super catch, etc.) before it trips the
breaker (blows a fuse). A motor will not burn out (or start) on a
protected
circuit that is rated too low for the motor (the breaker trips). 20 A
is
fine for your lathe.
Regards,
Hank