What this part is and what it does
The Siemens 3RU2116-0FB1 is a SIRIUS thermal overload relay, size S00, designed to protect motor circuits against sustained overloads. It mounts stand-alone with screw-type terminals and carries a CLASS 10 trip characteristic, meaning it will trip within 10 seconds at 600% of the set current — fast enough to protect standard induction motors during a locked-rotor event. The auxiliary switch is integrated, so no separate add-on block is needed for the trip signal. Rated for line voltages up to 690 V, with auxiliary contact ratings of 2 A at 24 V, 2 A at 230 V, 1 A at 400 V, and 0.75 A at 690 V.
Key ratings and what they mean for fit
Trip Class 10 means the relay clears a locked-rotor condition within 10 seconds, matching the thermal withstand of standard IEC motors. The size S00 frame fits within the SIRIUS compact footprint — 45 mm wide, 89 mm tall, 80 mm deep — so it occupies minimal DIN-rail space in a motor control centre. Temperature compensation is active from -40 to +60 °C, keeping the trip curve stable across a heated panel or cold installation. Operating ambient spans -40 to +70 °C; storage and transport survive -55 to +80 °C. The M3 main-contact screws accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded wire, which covers the control-circuit wiring typical for S00 contactors.
Panel and wiring integration
Mounts in any position — no derating required for side or horizontal orientation. Screw-type terminals for the main circuit; the screwdriver spec calls for a Pozidriv PZ 2 tip with a shaft diameter of 5 to 6 mm. The auxiliary contact is integrated, so the trip-signal wiring terminates directly on the relay without a separate aux block. Stand-alone installation means it does not require a dedicated mounting base beyond the DIN rail.