Circuit breaker parts 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 parts of a circuit breaker and their functions are as follows:

  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.
  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.
  5. Thermal Trip Unit: This type of trip unit uses a thermal sensor to detect overheating and trip the circuit.
  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 reduces the risk of electrical shock.
  7. Arc Suppressor: The arc suppressor is a device that is designed to absorb the energy of the arc that forms when the circuit breaker trips. It helps to prevent re-ignition of the arc and reduces the risk of electrical shock.
  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. Trip Coil: The trip coil is a coil of wire that is used to detect the overcurrent condition and send a signal to the trip unit to trip the circuit.
  10. Operating Handle: The operating handle is the part of the circuit breaker that is used to manually trip the circuit or reset the breaker after it has tripped.
  11. Indicator: The indicator is a light or flag that is used to indicate whether the circuit breaker is in the "on" or "off" position.
  12. Grounding Terminal: The grounding terminal is the part of the circuit breaker that is used to connect the circuit breaker to the grounding system.
  13. Neutral Terminal: The neutral terminal is the part of the circuit breaker that is used to connect the circuit breaker to the neutral bus.
  14. Line Terminal: The line terminal is the part of the circuit breaker that is used to connect the circuit breaker to the line bus.

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