What role does the capacitor play in starting and running the motor

Here's how capacitors function in the starting and running of motors:

Starting Capacitors (Start Capacitors):

Starting capacitors are used in single-phase induction motors, which are commonly found in appliances like air conditioners, refrigerators, and compressors. The primary purpose of a starting capacitor is to assist in the initial rotation of the motor when it's first powered on. Here's how it works:

Initial Phase Shift: When the motor is first powered, the starting capacitor is connected in series with the start winding (a secondary winding in the motor). The combination of the start winding and the starting capacitor creates a phase shift in the current flowing through the winding.

Increased Starting Torque: The phase shift created by the capacitor helps generate a rotating magnetic field in the motor. This rotating field produces a higher starting torque, which is necessary to overcome the inertia of the motor and start it turning.

Automatic Disconnection: After the Capacitor asynchronous motor reaches a sufficient speed and starts running, a centrifugal switch or relay built into the motor disconnects the starting capacitor from the circuit. This prevents the capacitor from affecting the motor's ongoing operation, as it's only needed during startup.

Running Capacitors (Run Capacitors):

Running capacitors, on the other hand, are used in both single-phase and three-phase induction motors. Unlike starting capacitors, running capacitors remain connected to the motor circuit throughout the motor's operation.

Here's their role:

Phase Shift Correction: Running capacitors are connected in parallel with the motor's main winding or run winding. They create a phase shift that helps bring the motor's current closer to being in-phase with the voltage supply. This phase correction improves the motor's power factor and efficiency.

Steady-State Operation: Running capacitors assist in maintaining a constant and smooth rotation of the motor. They help to optimize the motor's performance under varying load conditions.

Increased Efficiency: By improving the power factor and reducing reactive power consumption, running capacitors contribute to the overall efficiency of the motor. This can lead to energy savings in motors used for various applications.

Overheating Prevention: Running capacitors can help prevent overheating of the motor by improving its performance and reducing the risk of stalling under heavy loads.