What it is and what it does
The Siemens 3RU1116-1CC1 is a SIRIUS thermal overload relay, Size S00, designed to protect motors against overload and phase failure. It's the part that sits between the contactor and the motor, monitoring current and tripping on sustained overcurrent. Trip class CLASS 10 means it will trip within 10 seconds at 7.2× the rated current — fast enough to protect standard induction motors during a locked-rotor event, without nuisance tripping on normal starting inrush. Rated for AC-3 duty up to 690 V, this relay handles the switching of squirrel-cage motors under load. The main circuit uses cage clamp terminals accepting 2x (0.5... 2.5 mm²) solid or 2x (0.5... 1.5 mm²) finely stranded with ferrule.
Mounting and environment
Mounts stand-alone on a vertical surface, rotatable ±135° and tiltable ±45° front-to-back. The 45 mm width and 92 mm height fit the S00 footprint common in Siemens motor starter assemblies. Depth is 78 mm — check clearance behind the panel door. Front-side protection is IP20 — safe for finger contact inside an enclosed panel, but not for washdown environments. Operating temperature range -20 to +70 °C, storage and transport -55 to +80 °C. Shock rated at 8g for 10 ms. ATEX certification (DMT 98 ATEX G 001) allows use in potentially explosive atmospheres when paired with an appropriate contactor and upstream protection. The relay itself is not an ignition source under normal operation.
Auxiliary contact note
This relay comes with 0 factory-fitted auxiliary contacts. Add a separate auxiliary switch block that clips onto the side. The side clearance required is 6 mm.