What it is and what it does
The Siemens SIRIUS 3RU2116-0EB0-ZX95 is a size S00 thermal overload relay — the part that sits between a contactor and the motor, watching for overcurrent and tripping the control circuit before the winding cooks. It's Class 10, meaning it must trip within 10 seconds at 7.2× the full-load current setting, which is the standard for standard-duty induction motors (pumps, fans, compressors) that don't need an ultra-fast trip.
Mounting and wiring
This relay fastens directly to the contactor — no extra DIN-rail bracket needed, which saves a slot in the panel. The main circuit uses screw-type terminals accepting 2× (0.5... 1.5 mm²) or 2× (0.75... 2.5 mm²) solid or stranded copper. The auxiliary switch is integrated, and there's a dedicated terminal for the 'Tripped' message output — useful for feeding a remote alarm or PLC input without adding a separate aux block.
Ratings and environment
Rated insulation voltage is 690 V, with AC-3e switching capability up to that same voltage. The thermal element compensates for ambient temperature between -40 and +60 °C, so it won't nuisance-trip in a hot panel or cold warehouse. Operating temperature range is -40 to +70 °C; storage and transport handle -55 to +80 °C. MTTF under high-demand mode is 2,280 years — that's a reliability figure, not a service life, but it tells you the design is solid for continuous-duty applications.