The circuit breaker is a switching / protection electrical device with the ability to interrupt circuits under normal conditions and also to automatically interrupt them under abnormal operating conditions such as short circuits, short or long term overloads and even undervoltage.
They act as load protection and are specified as a function of the rated current or current range of the circuit to be protected, in addition to the acting classes represented by letters (A, B, C ...) which are defined according to the type of circuit. that you want to protect.
Most commonly used circuit breakers do not allow actuation current adjustment, which is fixed and visibly printed generally on the front of the component.
They may also be classified as non-pole single-phase circuit breakers (single phase), bipolar for phase and neutral use or phase and phase, three-phase for use in three-phase non-neutral and tetrapolar systems for use in three-phase systems of the neutral conductor.
