In a capacitor-start motor, the starting capacitor is placed in series with the Start winding during startup.

In a capacitor-start motor, the starting capacitor is placed in series with the Start winding during startup.

• A. Run winding
• B. Start winding
• C. Centrifugal switch
• D. Ground

Answer: (B)

The starting capacitor is placed in series with the start winding to create a large, phase-shifted current that gives the motor a strong starting torque. When the capacitor and start winding form a circuit, the current through the start winding leads the supply voltage, producing a near 90-degree phase difference between the currents in the start and run windings. This phase relationship generates a rotating magnetic field with a strong starting component, which helps the motor begin to rotate. Once the motor reaches a sufficient speed, a centrifugal switch disconnects the starting capacitor (and the start winding) to prevent overheating and unnecessary energy use, leaving only the run winding in operation. Ground isn’t involved in this starting method, and the run winding alone wouldn’t provide the necessary starting torque.

The starting capacitor is placed in series with the start winding to create a large, phase-shifted current that gives the motor a strong starting torque. When the capacitor and start winding form a circuit, the current through the start winding leads the supply voltage, producing a near 90-degree phase difference between the currents in the start and run windings. This phase relationship generates a rotating magnetic field with a strong starting component, which helps the motor begin to rotate. Once the motor reaches a sufficient speed, a centrifugal switch disconnects the starting capacitor (and the start winding) to prevent overheating and unnecessary energy use, leaving only the run winding in operation. Ground isn’t involved in this starting method, and the run winding alone wouldn’t provide the necessary starting torque.