What it is and what it does
The Siemens 3RU1116-1KC1 is a SIRIUS thermal overload relay in Size S00, designed to protect motors against overload and phase failure. Its CLASS 10 trip characteristic means it will trip within 10 seconds at 7.2× the current setting — fast enough to protect standard induction motors during a stalled-rotor condition without nuisance tripping during normal starting. It mounts stand-alone or directly onto a contactor, with cage clamp terminals accepting 2x (0.5... 2.5 mm²) solid or finely stranded wire. The IP20 front protection keeps fingers out of the live terminals inside the panel. Rated for AC-3 duty up to 690 V, with a surge voltage withstand of 6 kV. Power dissipation is 6.6 W total (2.2 W per pole) in hot operating state — factor that into enclosure thermal calculations if the panel is densely packed.
Where it fits — panel and environment
Dimensions are 45 mm wide, 92 mm high, 78 mm deep — a compact footprint that slides into a standard DIN-rail or direct-mount layout. Clearance requirements: 0 mm upwards, forwards, backwards, and downwards; 6 mm at the side. That zero-clearance top and bottom means you can stack relays without leaving ventilation gaps, though the 6 mm side gap must be respected for heat dissipation. Operating temperature range is -20 to +70 °C, storage/transport from -55 to +80 °C. Rated for altitudes up to 2 000 m without derating. Shock resistance is 8g for 10 ms — typical for industrial cabinet mounting on a machine base. Mounting position is flexible: vertical surface with ±135° rotation or ±45° tilt front/back. That covers most panel orientations without needing a special bracket.
Compliance and approvals
The 3RU1116-1KC1 carries ATEX protection type DMT 98 ATEX G 001, so it is approved for use in potentially explosive gas atmospheres. Relative humidity tolerance is 100% during operation — condensation-proof for humid environments.