The Siemens 3RU2116-1AC0-ZW97 is a SIRIUS-branded thermal overload relay in size S00, designed for direct mounting onto a contactor. It uses a thermal bimetallic release mechanism and is rated for Trip Class 10. Rated insulation voltage is 690 V, and the main circuit connects via spring-loaded terminals accepting 2× (0.5…2.5 mm²) solid or stranded wire — no screw torque to verify, which speeds panel wiring. The auxiliary switch is integrated, with contact ratings of 2 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V, covering typical PLC and contactor coil loads.
Mounts directly onto a contactor via the fastening method specified as 'contactor mounting' — no DIN-rail adapter needed, but the relay footprint (87 mm height, 45 mm width, 70 mm depth) matches the SIRIUS S00 contactor frame. Temperature compensation is active from -40 to +60 °C, meaning the trip curve stays accurate across a wide ambient range without manual adjustment.
Trip Class 10 is the standard for general-purpose motor protection — it allows enough inrush time for a motor to start under load without nuisance tripping, but clears fast enough to prevent winding damage during a stall. The 690 V rated insulation voltage covers 400 V and 480 V systems with margin; the relay also carries kW ratings at 400 V (0.55 kW), 500 V (0.75 kW), and 690 V (1.1 kW), matching typical motor frame sizes for S00 contactors. The auxiliary contact ratings are given at multiple voltages — note that the 24 V DC rating is 2 A, while at 60 V DC it drops to 0.3 A, reflecting the DC arc extinction limit. For AC loads, the 230 V rating of 2 A is typical for pilot duty. The integrated auxiliary switch means no separate add-on block is needed for feedback to the PLC.