The Siemens SIRIUS 3RU1136-4GB0-ZX95 is a thermal overload relay in the S2 size, designed to protect motors against overload and phase failure by tripping a connected contactor when the motor current exceeds the set threshold for too long. The relay mounts directly onto a contactor (contactor mounting), saving DIN-rail space and keeping the power loop short — common in motor starter assemblies inside control panels.
The S2 frame size handles motor currents in the mid-range of the SIRIUS family — check the specific current setting range on the relay nameplate to confirm it covers your motor FLA. Screw-type terminals on both the main and auxiliary circuits accept stranded wire up to 35 mm² on the mains and 2.5 mm² on the auxiliaries, with solid wire ranges of 2x (0.5…1.5 mm²) and 2x (0.75…2.5 mm²) respectively — sized for panel wiring with standard ferrule or bare conductors. Power dissipation is 5.2 W per pole; in a three-pole motor circuit that's about 15.6 W total heat to vent inside the enclosure — factor that into your panel thermal budget. Shock resistance of 8g / 10 ms means it will hold calibration under normal machine vibration; not rated for continuous high-g applications like engine mounts.
The ATEX certification (DMT 98 ATEX G 001) means it can be part of a motor starter in a potentially explosive gas atmosphere, provided the rest of the starter assembly also meets the zone requirements.