Definition
Definition :
There is discrimination of protection devices if on appearance of a fault at a point of the network, the fault is eliminated by the protection device located immediately upstream. Another similar term is coordination between protection devices. In the following diagram, two circuit-breakers A and B are serial connected. Three degrees of discrimination are possible between them: total, partial and non.
There are a number of techniques. For thermal magnetic circuit breakers, only current and time discrimination are chosen. The case of residual current discrimination is not dealt with, as the study is limited to the two techniques mentioned and to the faults generated by overcurrents.
