What It Is and Where It Fits
The Siemens 3RU2116-0AC0 is a SIRIUS thermal overload relay, Size S00, designed to protect motor circuits against overload and phase failure. It mounts directly onto a contactor, saving DIN-rail space and simplifying the wiring run between the contactor output and the motor. Trip Class 10 means it will trip within 10 seconds at 7.2× the full-load current setting — fast enough to protect standard induction motors during a stalled-rotor condition without nuisance tripping on normal starting curves. Rated for 690 V, with auxiliary contact ratings spanning 24 V (2 A) up to 690 V (0.75 A), so it can switch a PLC input or a contactor coil directly across common control voltages.
Sourcing and Lifecycle
RoHS compliance is confirmed with a substance prohibitance date of 10/01/2009, covering the standard EU directive scope.
Integration Notes
Mounts on the contactor via the fastening method, not on a DIN rail — so the panel layout needs the contactor footprint first. The relay body measures 45 mm wide, 87 mm high, and 70 mm deep, fitting into the S00 envelope common across the SIRIUS 3RU2 line. Spring-loaded terminals accept 2x (0.5... 2.5 mm²) solid or stranded wire. A 3 mm screwdriver shaft is specified for the terminal screws. Temperature compensation is active from -40 to +60 °C, and the relay can be mounted in any position, which helps in tight enclosures where airflow is restricted.