What it is and where it fits
The Siemens 3RU1116-1BC1 is a SIRIUS thermal overload relay, size S00, designed for motor protection in control panels. CLASS 10 trip curve means it will trip within 10 seconds at 7.2× the set current — fast enough to protect standard induction motors during a stall or locked-rotor event without nuisance tripping on normal starts. Rated for AC-3 duty up to 690 V, this relay mounts stand-alone on a vertical surface with ±135° rotation and ±45° tilt allowance. The IP20 front protection means it's suitable for enclosed panel installation where incidental finger contact is the only exposure. Cage clamp terminals on the main circuit accept 2x (0.5... 2.5 mm²) solid or 2x (0.5... 1.5 mm²) finely stranded with ferrule — no screw torque to verify, just strip to 8 mm and push in. No auxiliary contacts are built in (0 auxiliary contacts), so plan for a separate contactor block if you need status feedback.
Lifecycle and sourcing reality
For BOM freeze or PCN watch, the SIRIUS series is a mature, widely deployed platform. If a second-source gate is needed, the closest functional peer is the 3RH6131-1BF40 — same size S00 footprint, but verify the auxiliary contact configuration and coil voltage match your circuit, as the 3RU1116-1BC1 carries zero auxiliary contacts natively.
Environmental and compliance
Operating temperature range is -20 to +70 °C, storage and transport -55 to +80 °C. Withstands 100 % relative humidity during operation. Shock rated at 8g for 10 ms. ATEX protection type DMT 98 ATEX G 001 is listed, indicating suitability for potentially explosive gas atmospheres when installed per the associated system certificate. Surge voltage resistance is 6 kV. Maximum operating altitude is 2 000 m without derating. Power dissipation at AC in hot operating state is 5.7 W total, 1.9 W per pole — factor this into enclosure thermal calculations.
Mounting and clearances
Dimensions: 45 mm wide, 92 mm high, 78 mm deep. Stand-alone installation with no minimum clearance required upwards, forwards, backwards, or downwards. Side clearance is 6 mm. The size S00 form factor matches the standard Siemens SIRIUS contactor footprint for direct coupling.