[ Bruce Newman wrote:
> When I energize the relay in the automatic starter, the motor turns
> on and comes up to speed but then turns off after a few seconds.
> The starter has two heater coils that seem to be heating up and
> throwing some kind of internal safety switch that shuts off the power.
Yes, those are heater coils that function to heat a tube that has
solder inside, which melts, allowing the overload to trip.
I worked at Allen-Bradley in the 1950s, testing a few thousand of them.
The coils vary depending upon the current limit desired, and are meant
to allow motor inrush high currents, yet prevent overloads. So your
question is now whether the current of the limiters, or to the motor is
too high. It may be too high if the motor is attempting to run on the
starter winding instead of the run winding.
Will Herzog
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