changed by interchanging the start winding leads, while those of the run winding remain the same. Unlike the three-phase motor, the single-phase capacitor-start motor must be allowed to slow down before any attempt to reverse the direction of rotation. The centrifugal switch in the start winding circuit opens at approximately 75 percent of the motor speed and must be allowed to reclose before the motor will reverse. C ertain machine tool operations require a repeated forward and reverse action in their operation. Figure 8-32 illustrates a reciprocating machine process that uses two limit switches to provide automatic control of the motor. Each limit switch (LS1 and LS2) has two sets of contacts, one normally open and the other normally closed. The operation of the circuit can be summarized as follows: • The start and stop push buttons are used to initiate and terminate the automatic control of the motor by limit switches.
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