What it is and what it does
The Siemens 3RU2116-1CC0-ZX95 is a SIRIUS thermal overload relay — size S00, Trip Class 10 — designed to protect motors against overload and phase loss by monitoring current and tripping the associated contactor when the thermal model reaches its limit. Trip Class 10 means it must trip within 10 seconds at 7.2× the full-load current setting, which is the standard for standard-duty motor starts — pumps, fans, compressors that don't need a long acceleration curve. The auxiliary switch is integrated and rated for switching: 2 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V — enough to signal a PLC input or a status lamp directly.
Mounting and integration
This relay mounts directly onto a contactor (contactor mounting). Size S00 is the smallest frame in the SIRIUS family. The main current circuit uses spring-loaded terminals (cage-clamp style), accepting 2× (0.5 to 2.5 mm²) solid or stranded wire. No screw torque to verify — just strip to 8 mm and push in. Mounting position is any, and the temperature compensation range is -40 to +60 °C, so it works in outdoor cabinets or unheated plant areas without derating the trip curve.
Sourcing and lifecycle
The -ZX95 suffix indicates a special version with the 'Tripped' message note.
Physical fit and environment
Dimensions: 45 mm wide, 87 mm tall, 70 mm deep — fits in a standard 45 mm-wide contactor footprint. Storage and transport temperature range is -55 to +80 °C; operating range is -40 to +70 °C.