Which statement describes a dual-capacitor (capacitor-start capacitor-run) motor?

Which statement describes a dual-capacitor (capacitor-start capacitor-run) motor?

• A. Uses two capacitors: a start capacitor (high value) and a run capacitor (lower value)
• B. Uses a single capacitor only
• C. Has no run capacitor
• D. Always provides lower starting torque than capacitor-start motors

Answer: (A)

Dual-capacitor motors use two capacitors in the auxiliary winding: a start capacitor with a high value used only during startup to create a strong phase shift and high starting torque, and a run capacitor with a lower value that stays in the circuit while the motor runs to improve running torque and power factor. The start capacitor is typically engaged briefly via a centrifugal switch (or similar) and then disconnected, while the run capacitor remains in circuit for efficient operation. This combination of a large start capacitor plus a continuing smaller run capacitor is what defines a capacitor-start capacitor-run motor. The other ideas don’t fit because a single capacitor isn’t enough for both starting and running optimization, a run capacitor is indeed used in this design, and capacitor-start capacitor-run motors don’t inherently have lower starting torque than capacitor-start-only types — they can actually achieve strong starting torque thanks to the large start capacitor.

Dual-capacitor motors use two capacitors in the auxiliary winding: a start capacitor with a high value used only during startup to create a strong phase shift and high starting torque, and a run capacitor with a lower value that stays in the circuit while the motor runs to improve running torque and power factor. The start capacitor is typically engaged briefly via a centrifugal switch (or similar) and then disconnected, while the run capacitor remains in circuit for efficient operation. This combination of a large start capacitor plus a continuing smaller run capacitor is what defines a capacitor-start capacitor-run motor.

The other ideas don’t fit because a single capacitor isn’t enough for both starting and running optimization, a run capacitor is indeed used in this design, and capacitor-start capacitor-run motors don’t inherently have lower starting torque than capacitor-start-only types — they can actually achieve strong starting torque thanks to the large start capacitor.