What it is and what it does
The Siemens 3RU2116-0EB1 is a SIRIUS thermal overload relay, size S00, with a Class 10 trip curve. The relay uses a bimetallic thermal release, temperature-compensated from -40 to +60 °C, so ambient shifts in the panel don't drift the trip point. It mounts in any position, standalone, and accepts screw-type terminals for the main circuit — 2× (0.5 to 2.5 mm²) solid or stranded per pole. The integrated auxiliary switch provides a normally-open and normally-closed contact for signaling the tripped state to a PLC or contactor coil; the 'Note for message Tripped' on the nameplate confirms the NO/NC assignment for that status.
Auxiliary contact ratings — what they mean for your control circuit
The auxiliary contacts are rated for 2 A at 24 V, 3 A at 120 V, and 2 A at 230 V — enough to drive a small PLC input or a contactor coil directly, but check the inrush if you're switching a DC coil with a high holding current. At 400 V the rating drops to 1 A, and at 690 V to 0.18 kW — the contacts are sized for control, not power switching.
Mounting and integration
Size S00 fits the standard DIN-rail footprint for Siemens SIRIUS contactors in the same frame. Depth is 80 mm, width 45 mm, height 89 mm — leaves room for auxiliary contact blocks alongside on the rail. Screw terminals accept Pozidriv PZ2 bits; the screwdriver shaft diameter should be 5 to 6 mm.