The Siemens 3RU2116-0EJ0 is a SIRIUS thermal overload relay in size S00, designed for direct contactor mounting to protect motor circuits against overload and phase imbalance. It is rated for a maximum operating voltage of 690 V and carries a Trip Class 10 characteristic, meaning it will trip within 10 seconds at 7.2× the set current — the standard for standard-duty motor starts like pumps and fans. The auxiliary switch is integrated and rated for switching: 2 A at 24 V, 3 A at 120 V, 2 A at 230 V, 1 A at 400 V, and 0.3 A at 60 V, among other points. These ratings cover both control-circuit and signal-level loads typically found in a panel.
Integration and mounting
Mounts directly onto the contactor via the fastening method specified for S00 frames — no separate DIN-rail footprint needed, which saves panel width. The relay can be installed in any mounting position, and the main circuit connection uses ring cable lugs (M3 screw). Dimensions are 45 mm wide, 76 mm high, and 70 mm deep — compact enough for dense panel layouts. Temperature compensation is active from -40 °C to +60 °C, and the relay operates reliably between -40 °C and +70 °C ambient.
The relay carries a note for message "Tripped" — this is the signal output state when the overload release has activated, indicating the auxiliary switch changes state to report the fault condition to a PLC or indicator. MTTF with high demand rate is 2,280 years, reflecting the electromechanical reliability of the thermal bimetal design.