Circuit Breakers

Circuit breakers are electrical safety devices designed to protect electrical equipment from short circuit damage, overheating, and overcurrent failures. The APL211-9739-20 circuit breaker is a type of circuit breaker with a specific application field and working principle.

The APL211-9739-20 Application Field

The APL211-9739-20 circuit breakers are designed to be used in medium-voltage distribution systems up to 15kV. It offers circuit protection for short circuit and ground fault protection at any allowed location in medium-voltage distribution schemes. This breaker is used in switchgear, overhead line, and panels when it comes to residential, commercial, industrial, and special applications.

APL211-9739-20 Working Principle

The APL211-9739-20 circuit breaker is based on an magnetic-hydraulic operating principle. Its hydraulic system is the fluid-filled part of the three main components of the breaker: the magnetic device, the hydraulic device, and the mechanical device. In order to operate, the magnetic device initially detects a fault current on the distribution line. This feeds a signal to a coil connected to the hydraulic device that releases pressurised hydraulic oil into the breaker. This increase in hydraulic pressure is used to operate the mechanical components of the breaker. The mechanical components open or close the contacts, depending on the direction of the current flow. The hydraulic system also helps absorb some of the internal energy generated by the fault current, so that it can be dissipated.

Conclusion

The APL211-9739-20 circuit breaker is a type of circuit breaker specifically designed for medium-voltage distribution systems. It offers circuit protection against short circuit and ground fault protection, and is used in a variety of residential, commercial, industrial, and special applications. The breaker\'s principle of operation is based on a magnetic-hydraulic system, where a detected fault current feeds a signal to the hydraulic device, which increases the pressure of hydraulic oil and operates the mechanical device to open or close the breaker\'s contacts.