The Siemens 3RU6116-0AB0 is a SIRIUS thermal overload relay for motor protection, sized S00 and rated for a 0.11 to 0.16 A adjustable current range. It's a Class 10 trip device, meaning it will open the circuit within 10 seconds at a 7.2x overload — fast enough to protect the motor windings from a locked-rotor condition without nuisance tripping on a normal start-up. The relay mounts directly onto the contactor (fastening method: contactor mounting), so it shares the same DIN-rail footprint and saves panel space.
The 0.11–0.16 A adjustable range is the headline fit parameter — pair this relay with a motor whose full-load current falls inside that window. Trip Class 10 matches most general-purpose induction motors (pumps, fans, conveyors) with moderate start times; a Class 20 or 30 would be needed for high-inertia loads like crushers or centrifuges. The size S00 form factor is the smallest Siemens contactor frame, so the relay stays compact: 45 mm wide, 76 mm tall, 70 mm deep. It mounts in any position, which helps when panel layout is tight.
Both the main current circuit and the auxiliary/control circuit use screw-type terminals. The main terminals accept 2x (0.5–1.5 mm²) solid/stranded or 2x (0.75–2.5 mm²), with a tightening torque of 0.8–1.2 N·m. The auxiliary terminals handle 2x (0.5–1.5 mm²) or 2x (0.75–2.5 mm²) and AWG equivalents. For a panel-builder, the 6 mm required spacing to grounded parts at the side is the key clearance to respect — pack the DIN rail accordingly.