power circuit breaker (protective device) (PCB)
Circuit breakers, Power Circuit Breaker (PCB), are used in low and high voltage technology for switching high currents. Depending on the application, a distinction is made between open circuit breakers, air circuit breakers( ACB), miniature circuit breakers (MCB), compact circuit breakers, molded circuit breakers (MCB), and load break switches, load break switches ( LBS).
Circuit breakers can be single- or three-pole switches and are characterized by their ability to switch currents of several kilo-amperes (kA). Up to approximately one mega- ampere( MA). Appropriate circuit breakers can be controlled manually, motor-driven, by spring mechanisms, or by solenoid devices. Some circuit breakers can be operated remotely via Profibus, Modbus or Ethernet. Circuit breakers are tripped by the overcurrent of short circuits or by thermal sensors.
To avoid arcing when the switch contacts are separated, circuit breakers have special spark extinguishing chambers or extinguish the arc with oil. There are also circuit breakers that switch at zero crossing and where the spark gap is deionized so that no arcing can occur.