What It Is and Where It Fits
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. With a rated insulation voltage of 690 V and operating frequency of 50 to 60 Hz, it covers standard three-phase motor applications up to that voltage.
Key Ratings and What They Mean for Your BOM
The Trip Class 10 rating means the relay will trip within 10 seconds at 7.2× the current setting — fast enough to protect standard induction motors during a locked-rotor event without nuisance tripping on normal starting transients. 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.
Mounting and Integration
The S00 footprint measures 45 mm wide, 76 mm high, and 70 mm deep — a compact package that fits standard DIN-rail starter assemblies when paired with a matching contactor. Mounting position is any orientation, giving flexibility in tight enclosures. 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.
Lifecycle and Sourcing Reality
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.