The Siemens 3RU2116-1GJ0 is a SIRIUS thermal overload relay in the S00 frame size, designed to protect motors against overload and phase failure by monitoring current and tripping based on a CLASS 10 curve. It mounts directly onto a contactor (fastening method: contactor mounting), making it a compact, integrated solution for motor starter assemblies in control panels.
Motor power ratings are specified per voltage: 2.2 kW at 400 V, 3 kW at 500 V, and 4 kW at 690 V, so the same relay covers a range of motor sizes depending on your line voltage. The integrated auxiliary switch provides signal contacts rated across multiple voltages: 2 A at 24 V and 230 V, 3 A at 120 V, 1 A at 400 V — useful for feeding a PLC input or a status lamp. Thermal compensation is active from -40 to +60 °C, so the trip curve stays accurate in a hot panel or cold warehouse without manual adjustment.
Main circuit connections use ring cable lugs (M3 screw), while the auxiliary switch is integrated into the same housing — no separate add-on block needed.
For a plant spares crib, this is a fast mover on motor starters up to 4 kW at 690 V. Keep one on the shelf if you run S00 contactor assemblies.