RESIDUAL CURRENT CIRCUIT BREAKERS

I am new to the term RCCB. I found what it is.. Residual current circuit breakers(RCCB) are used for protection against indirect touching of parts under voltage, for prevention of lasting voltage on earthed parts because of a defect in electrical installation and for protection against direct contact of parts under voltage where the residual current is greater than 30ma. Residual current circuit breakers can be used in all systems where neutral and protective conductor are separated