Part identity and deployment context
The Siemens 3RU2116-0GJ0 is a SIRIUS thermal overload relay in size S00, designed for direct contactor mounting. It protects motors against overload and phase failure by monitoring the motor current and tripping the contactor when the thermal model reaches the trip threshold. The CLASS 10 trip characteristic means it will trip within 10 seconds at 7.2× the current setting, which is the standard for standard-duty induction motors driving pumps, fans, and conveyors.
Key ratings and what they mean for fit
The auxiliary contact ratings tell you what control voltage it can switch: 2 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V. These are the make/break capacities for the N/C and N/O contacts that signal the trip condition back to the PLC or contactor coil circuit. The relay is rated for a main circuit voltage up to 690 V, covering 400 V and 480 V systems common in industrial panels. Size S00 is the smallest frame in the SIRIUS relay family, matching the 3RT2 contactors in the same size class. The 45 mm width and 70 mm depth mean it fits standard DIN-rail enclosures without crowding adjacent devices. Mounting position is any, which simplifies layout in tight panels. Operating temperature range of -40 to +70 °C covers most indoor and outdoor cabinet environments. Storage range of -55 to +80 °C is typical for shipping and warehouse conditions.
Integration notes
Fastening is by contactor mounting — it snaps directly onto the matching SIRIUS 3RT2 contactor without additional hardware. Main circuit connections use ring cable lugs (M3 screws). The auxiliary switch is integrated into the relay body, so no separate auxiliary contact block is needed for the trip signal. Screwdriver shaft diameter 5 to 6 mm, Pozidriv PZ 2 tip for the terminal screws.