Tripping coils and Closing coils in circuit breakers

Circuit breakers are a critical component in electrical systems, designed to interrupt the flow of electricity in the event of a fault or overload. Two key elements in the operation of circuit breakers are the tripping coil and the closing coil.

What are Tripping Coils and Closing Coils?

The tripping coil and closing coil are electromagnetic devices used in circuit breakers to control their operation. The operation of the tripping coil and closing coil is based on the principles of electromagnetism. When an electric current passes through the coil, it creates a magnetic field. This magnetic field can exert a force on a nearby magnetic material, causing it to move. In the case of circuit breakers, this movement is used to open or close the electrical contacts.

• The tripping coil, also known as the trip coil, is responsible for opening the circuit breaker. When an electrical fault such as an overload or short circuit is detected, the relay sends a signal to the tripping coil, the tripping coil is energized. This creates a magnetic field that moves a mechanical latch, causing the circuit breaker to open and interrupt the current flow.
• The closing coil plays the opposite role. The closing coil is connected to a control switch operated by the user. When the switch is closed, it sends a signal to the closing coil, causing it to operate. When it is safe to resume the flow of electricity, the closing coil is energized. This generates a magnetic field that moves a mechanical latch in the opposite direction, causing the circuit breaker to close and allow current to flow again.

In addition, they allow the user to manually control the flow of electricity. By operating the control switch connected to the closing or tripping coil, the user can turn the electrical system on or off as needed.