The Siemens 3RB2065-1MC2 is a SIRIUS solid-state overload relay — the electronic equivalent of a bimetal relay, but with no moving thermal elements to drift or fatigue. That 0.05 W dissipation per pole (at AC in hot operating state) keeps the panel thermal budget low — relevant when multiple relays are packed on a DIN rail or inside a small enclosure. Rated for contactor mounting or stand-alone installation, it fits directly under a SIRIUS contactor or can be panel-mounted with busbar connections for the main circuit.
This overload relay protects three-phase AC motors in industrial automation — conveyors, pumps, fans, compressors — where a solid-state design is preferred over a bimetallic one for accuracy and repeatability. The ATEX Ex II (2) GD certification (PTB 06 ATEX 3001) means it can be installed in the safe area but is approved to protect motors located in Zone 1/21 gas or dust hazardous areas, as long as the associated contactor and wiring meet the installation rules.
Integration notes
Dimensions are 147 mm high, 145 mm wide, 156 mm deep — fits a standard 145 mm-wide DIN-rail footprint. The solid and stranded wire range accepts 0.5 … 4 mm² solid or 0.5 … 2.5 mm² finely stranded with ferrule, with dual-wire capability for daisy-chaining.