In a single-phase capacitor start-and-run motor, the minimum number of capacitors to be used in it is:

• A. 3
• B. 1
• C. 4
• D. 2

Answer: (D)

Capacitor start and capacitor run motor: Two capacitors are used for starting, but one of them is cut out when speed reaches 70 percent of the synchronous speed. The capacitor start-and-run motor starts with a high value and a low-value capacitor connected in parallel with each other but in series with the starting winding. This provides a very high starting torque. The centrifugal switch disconnects the high-value capacitor at 80 percent speed, but the lower value capacitor remains in the circuit.