Product Manual

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CHAPTER III
Major Motor Types
Alternating current (AC) induction motors are divided into two electrical
categories based on their power source – single phase and polyphase
(three phase).
AC Single Phase Types
Types of single-phase motors are distinguished mostly by the way they
are started and the torque they develop.
Shaded Pole motors have low starting torque, low cost, low efficiency,
and no capacitors. There is no start switch. These motors are used on
small direct drive fans and blowers found in homes. Shaded pole motors
should not be used to replace other types of single-phase motors.
PSC (Permanent Split Capacitor)
motors have applications similar to shaded
pole, except much higher efficiency, lower
current (50% - 60% less), and higher
horsepower capability. PSC motors have a
run capacitor in the circuit at all times. They
can be used to replace shaded pole motors
for more efficient operation and can be used
for fan-on-shaft fan applications, but not for
belted fans due to the low starting torque.
Split Phase motors have moderate to low
starting torque (100% - 125% of full load),
high starting current, no capacitor, and a start-
ing switch to drop out the start winding when
the motor reaches approximately 75% of its
operating speed. They are used on easy-to-
start belt drive fans and blowers, as well as
light-start pump applications.
PSC circuit diagram