Basic Concept of Load Shedding Circuit Breakers

Load shedding circuit breakers are electrical devices designed to interrupt the flow of current in a circuit under normal operating conditions, that is, when there is no fault or short circuit in the system. Its main function is to allow the safe opening and closing of an electrical circuit for maintenance operations, maneuvers or changes in the network configuration.

These devices differ from protective circuit breakers, since they are not designed to act in the event of electrical faults, but rather to carry out the controlled and safe disconnection of loads or sections of the electrical system. They are essential in medium and low voltage networks to guarantee the safety of personnel and the integrity of the equipment.

Opening and closing mechanism

The load shedding circuit breaker operates through an electromechanical or electronic mechanism that allows the opening and closing of the circuit under nominal current conditions. Its design ensures that disconnection is carried out without producing dangerous electrical arcs or damage to internal contacts, using arc extinction systems such as extinction chambers or vacuum chambers.

The circuit breaker opening process is carried out when a manual or automatic order is received, guaranteeing that the current that circulates is as expected to avoid damage due to sudden disconnection. Its ability to interrupt current is limited to the rated load current and is not designed to interrupt high fault currents.

Therefore, the load shedding circuit breaker must be selected and calibrated appropriately for the load and system conditions, ensuring its correct performance and safe operation.

Nominal capacity and technical parameters

Load breaking circuit breakers are specified by their rated current capacity, maximum operating voltage and the network frequency, generally 50 or 60 Hz. In addition, parameters such as the load current breaking capacity, the rated insulation voltage and the mechanical life of the equipment are considered.