The Siemens 3RU2116-1DB0 is a SIRIUS thermal overload relay, size S00, Trip Class 10. It mounts directly onto a contactor.
Rated insulation voltage is 690 V, and the AC-3e rated maximum is also 690 V, so it's comfortable on 400 V and 480 V systems with headroom. The auxiliary contact — an integrated switch — carries 2 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V. That's the signal you send to the PLC or a contactor coil to say 'motor's hot.' At 690 V the contact still handles 0.75 A, enough for most pilot-duty circuits. Power dissipation per pole is 1.9 W. In a crowded panel with a dozen relays, that heat adds up — plan your ventilation or derating if the enclosure is sealed.
Fastens directly to the contactor — no DIN-rail foot needed. Mounting position is any, which helps when you're shoehorning gear into a tight cabinet. Main circuit terminals are screw-type, accepting 2× (0.5 to 1.5 mm²) or 2× (0.75 to 2.5 mm²) solid or stranded. Use a Pozidriv PZ2 bit, shaft diameter 5–6 mm. Depth is 70 mm, width 45 mm, height 76 mm — that's the S00 footprint.
Temperature compensation is active from -40 to +60 °C, so the trip curve stays honest even if the panel sits next to a hot bearing housing. Substance prohibitance date is 10/01/2009, which aligns with RoHS compliance — no lead, cadmium, or other restricted materials above threshold. MTTF with high demand rate is 2,280 years — a reliability figure for safety-related applications, not a warranty.