What it is and where it fits
The Siemens 3RU1116-1JB0-ZW95 is a SIRIUS thermal overload relay in the S00 frame size, designed to protect three-phase motor circuits against overload and phase failure. It mounts directly onto a contactor via the fastening method specified as contactor mounting, so it drops into the same DIN-rail footprint as the SIRIUS contactor family — no extra panel space needed beyond the 45 mm width and 78 mm depth of the relay itself. Trip class is CLASS 10, meaning it will trip within 10 seconds at 7.2× the current setting — standard for general-purpose motor starting where the load doesn't have a long acceleration ramp.
Mounting and wiring realities
The 3RU1116-1JB0-ZW95 accepts solid and finely stranded conductors with core-end processing: 2× (0.5 … 1.5 mm²) and 2× (0.75 … 2.5 mm²) per terminal, or the AWG equivalents 2× (20 … 16) and 2× (18 … 14). Both main and auxiliary/control circuits use screw-type terminals — no spring-cage adapters needed, but you'll want a Pozidriv bit on the torque driver. Mounting position is flexible: vertical surface with ±135° rotation or ±45° tilt front/back. Clearances: 0 mm upwards, forwards, backwards, and downwards; 6 mm at the side. That zero-clearance top and bottom means you can stack relays tight in a multi-row panel without derating for airflow — handy when you're filling a crowded enclosure.
Environmental and compliance
Operating temperature range is -20 … +70 °C, storage and transport -55 … +80 °C. The relay carries IP20 finger-safe touch protection on the front and is approved for ATEX Zone 2 / Zone 22 (DMT 98 ATEX G 001). Surge voltage resistance is rated at 6 kV. Shock resistance is 8g / 10 ms. Relative humidity during operation can hit 100 % — no derating needed for condensing environments.
Auxiliary contact ratings
Auxiliary contact ratings cover common control voltages: 1 A at 24 V, 3 A at 120 V, 2 A at 230 V, 1 A at 400 V. For DC applications: 0.22 A at 110 V, 0.22 A at 125 V, 0.11 A at 220 V. Power dissipation per pole is 2.2 W — factor that into your enclosure thermal budget if you're running near the upper ambient limit.