The Siemens 3RU1116-1GC1 is a SIRIUS thermal overload relay, size S00, designed to protect motors against overload and phase failure. It provides CLASS 10 trip characteristics, meaning it will trip within 10 seconds at 7.2× the set current — fast enough to protect standard induction motors during a locked-rotor event, provided the upstream short-circuit protection is coordinated correctly.
Ratings and deployment context
Rated for AC-3 duty up to 690 V, this relay handles the switching of motor loads in control panels. The S00 frame size and 45 mm width mean it occupies a single 45 mm slot on a DIN rail, with stand-alone installation permitted — no need for a separate base mounting plate in most enclosures. The IP20 front protection is standard for panel-mounted gear; the relay itself is not rated for washdown environments, so keep it inside the cabinet. Power dissipation at rated current in hot operating state is 6.6 W total, or 2.2 W per pole. That heat has to go somewhere — in a densely packed panel, ensure natural convection paths aren't blocked, or the internal bimetal may drift its trip point over time. The relay is rated for continuous operation from -20 to +70 °C ambient, with storage and transport range from -55 to +80 °C. Shock resistance is specified at 8g for 10 ms, which covers most vibration found in industrial motor control centers. The mounting position allows rotation of ±135° on a vertical surface and tilting ±45° forward and back — useful when the panel layout forces an odd angle, though the trip calibration assumes vertical mounting for best accuracy.
Conductor termination and wiring
Main circuit connections use cage clamp terminals, accepting solid conductors of 2x (0.5 to 2.5 mm²) or finely stranded with core end processing of 2x (0.5 to 1.5 mm²). AWG equivalents are 2x (24 to 14). The cage clamp provides a vibration-resistant connection without periodic retorquing — a genuine advantage in high-vibration MCC applications where screw terminals can loosen over a few years of thermal cycling.
Environmental and compliance
The relay carries ATEX protection type DMT 98 ATEX G 001, certifying it for use in potentially explosive gas atmospheres when installed in an appropriate enclosure. Surge voltage resistance is rated at 6 kV, and the reference code per DIN EN 81346-2 is F (protective device). Relative humidity during operation can reach 100 %, including condensation — but the IP20 front means the terminals themselves are not sealed, so the enclosure must handle the condensation.