What is the primary purpose of a motor capacitor?

What is the primary purpose of a motor capacitor?

• A. To prevent overheating
• B. To supply additional current
• C. To enhance starting torque and efficiency
• D. To act as a backup power source

Answer: (C)

The primary purpose of a motor capacitor is to enhance starting torque and efficiency. Capacitors are used in motors, particularly in single-phase induction motors, to create a phase shift in the current. This phase shift allows the motor to generate a rotating magnetic field, which is essential for starting the motor. When the motor starts, the capacitor provides the necessary displacement current that improves the torque at startup. This increased starting torque helps the motor overcome inertia and get going, making it particularly useful in applications where motors must start under load. Additionally, once the motor reaches a certain speed, the capacitor can disconnect from the circuit, improving the overall efficiency of the motor during operation. The other options, while they may have some relevance in specific contexts, do not capture the core function of motor capacitors as effectively as enhancing starting torque and efficiency. Understanding this role is crucial for properly selecting and troubleshooting HVAC systems that rely on motor-driven components.

The primary purpose of a motor capacitor is to enhance starting torque and efficiency. Capacitors are used in motors, particularly in single-phase induction motors, to create a phase shift in the current. This phase shift allows the motor to generate a rotating magnetic field, which is essential for starting the motor.

When the motor starts, the capacitor provides the necessary displacement current that improves the torque at startup. This increased starting torque helps the motor overcome inertia and get going, making it particularly useful in applications where motors must start under load. Additionally, once the motor reaches a certain speed, the capacitor can disconnect from the circuit, improving the overall efficiency of the motor during operation.

The other options, while they may have some relevance in specific contexts, do not capture the core function of motor capacitors as effectively as enhancing starting torque and efficiency. Understanding this role is crucial for properly selecting and troubleshooting HVAC systems that rely on motor-driven components.