Why Capacitor Start AC Synchronous Motors?
All Permanent Magnet AC Synchronous motors manufactured at Hurst are of the capacitor start variation. These motors, which are classified in the sub-fractional group, find various applications in situations requiring frequent and prolonged starting periods. As the name suggests, these motors run at synchronous speed. The speed of a single phase AC synchronous motor can be determined using the formula Synchronous speed (in RPM) = 120f/p where f is the frequency of the power supply and p is the number of poles. For the same starting torque, the capacitor motor when compared to the split-phase motor requires half of the current for starting. The auxiliary winding of the capacitor motor has twice the number of turns of the split-phase AC motor. A split-phase AC motor basically has an inductive auxiliary winding. The lesser current in the auxiliary winding of the capacitor motor results in less copper loss and subsequently less heat generated by that motor. Because of the capacitor in the w
