Parts of circuit breaker and their function

A circuit breaker is an electrical device that is designed to interrupt the flow of electrical current in an electrical circuit when the current exceeds a certain level, known as the trip point. The main parts of a circuit breaker and their functions are:

  1. Main Contact: The main contact is the moving part of the circuit breaker that makes and breaks the electrical circuit. It is typically a spring-loaded contact that opens and closes the circuit.
  2. Trip Unit: The trip unit is the electronic or electromechanical device that detects the overcurrent condition and sends a signal to the main contact to trip (open) the circuit. The trip unit is usually located in the circuit breaker's control panel.
  3. Thermal-Magnetic Trip Unit: This type of trip unit uses a combination of thermal and magnetic sensors to detect overcurrent conditions. The thermal sensor detects overheating, while the magnetic sensor detects excessive current flow.
  4. Magnetic Trip Unit: This type of trip unit uses a magnetic sensor to detect excessive current flow and trip the circuit breaker.
  5. Thermal Trip Unit: This type of trip unit uses a thermal sensor to detect overheating and trip the circuit breaker.
  6. Arc Chute: The arc chute is a metal plate or chamber that is designed to extinguish the arc that forms when the circuit breaker trips. It helps to prevent re-ignition of the arc and ensures safe operation.
  7. Arc Suppressor: The arc suppressor is a device that is designed to absorb the energy released when the circuit breaker trips and extinguish the arc.
  8. Spring: The spring is used to store energy and return the main contact to its normal position after the circuit breaker has tripped.
  9. Main Contact Spring: The main contact spring is used to return the main contact to its normal position after the circuit breaker has tripped.
  10. Trip Coil: The trip coil is a spring-loaded coil that is used to trip the circuit breaker when the current exceeds the trip point.
  11. Reset Button: The reset button is used to reset the circuit breaker after it has tripped. It is usually located on the front of the circuit breaker.
  12. Indicators: The indicators are lights or LEDs that indicate the status of the circuit breaker, such as whether it is tripped or reset.
  13. Grounding Terminal: The grounding terminal is used to connect the circuit breaker to the grounding system of the electrical panel.
  14. Busbar: The busbar is the metal strip that connects the circuit breaker to the electrical panel and provides a path for the electrical current to flow.

These are the main parts of a circuit breaker and their functions. The specific design and components may vary depending on the type and manufacturer of the circuit breaker.