What It Is and What It Does
The Siemens 3RU1116-0JB0-ZW96 is a SIRIUS-brand thermal overload relay, Size S00, designed to protect three-phase motors by monitoring motor current and tripping on sustained overload. It is a Class 10 device, meaning it will trip within 10 seconds at 7.2× the set current — the standard response for standard-start induction motors driving pumps, fans, and conveyors. The relay mounts directly to a contactor (contactor mounting fastening method), which simplifies panel wiring: the power circuit passes through the relay's bimetal strips, and the trip mechanism mechanically opens the contactor's hold-in coil circuit. The mounting position allows for a vertical mounting surface with +/-135° rotation and +/-45° tilt front-to-back, giving flexibility in crowded enclosures.
Physical Fit and Wiring
The relay measures 87 mm high, 45 mm wide, and 78 mm deep — the 78 mm depth is the dimension that matters most for panel depth clearance when mounted on a contactor. Zero clearance is required upwards, forwards, backwards, and downwards, with only 6 mm needed at the side, so it packs tightly into a DIN-rail layout. Main circuit terminals accept solid or finely stranded wire: 2x (0.5...1.5 mm²) and 2x (0.75...2.5 mm²), with AWG equivalents 2x (20...16) and 2x (18...14). Auxiliary and control circuits use the same screw-type terminals with 2x (20...16) and 2x (18...14) AWG capacity. This covers standard motor power and control wiring in most industrial panels.
Protection Class and Environmental Ratings
The front of the relay carries IP20 protection — finger-safe but not sealed against moisture or dust, so it belongs inside a panel or enclosure. It operates from -20 to +70 °C and can be stored or transported from -55 to +80 °C. The 100% relative humidity rating during operation means it can handle condensing environments inside a properly rated enclosure, but the IP20 front means the enclosure itself must keep liquid out. Shock resistance is rated at 8g for 10 ms, sufficient for most industrial machinery but not for high-vibration applications like crushers or large reciprocating compressors without additional damping.
Compliance and Lifecycle
The 3RU1116-0JB0-ZW96 carries ATEX certification (DMT 98 ATEX G 001), making it suitable for use in potentially explosive atmospheres when installed in the appropriate enclosure and with the correct contactor. This is a key differentiator for petrochemical and chemical process applications where the safety instrumented function must fail safe on demand — the relay's mechanical trip mechanism provides a failsafe opening of the motor circuit without relying on electronics. The lifecycle status is listed as current production. The part carries a substance prohibitance date of 07/01/2006, aligning with RoHS compliance. For compliance documentation (RoHS, REACH, IEC), the standard Siemens SIRIUS declaration of conformity and ATEX certificate are provided with the shipment.