Residual current circuit breakers LFE, LFN, OFI and residual current circuit breakers with overcurrent protection OLE/OLI are intended for the protection against dangerous contact with live and dead parts and against fire. The residual current circuit breakers with overcurrent protection OLE/OLI provide in addition overcurrent protection. The group contains devices limiting the number of undesirable switch-outs (type G) and enabling selective tripping (type S). All residual current circuit breakers are standardly connected by interconnecting busbars with circuit breakers LTP and LTS.