Protects against direct contacts
Protection against direct contact of a person with live parts of a powered installation is made by the insulation of live parts, by the establishment of devices which ensure inaccessibility or remoteness, with automatic switch-off or the Safety Extra Low Voltage (SELV).
Protects against indirect contacts
Two types of differential device, in conjunction with an earth connection: the differential switch and the residual circuit breaker. They are mainly characterized by their sensitivity (in mA), which is the minimum leakage current that causes the differential to react.
The differential switch, in conjunction with an earth connection, protects against indirect contacts. It has no protective device against overcurrents and short-circuits and so must be used in conjunction with a fuse-disconnecting switch or a circuit breaker located upstream.
RESIDUAL CURRENT CIRCUIT BREAKER
The Residual Current Circuit Breaker, in conjunction with an earth connection, both: