The Siemens 3RU2116-0FC0-ZW97 is a SIRIUS thermal overload relay in frame size S00, designed for motor protection with a CLASS 10 trip characteristic. It is rated for a maximum voltage of 690 V and operates at 50/60 Hz. This variant includes a spring-loaded terminal block for the main current circuit and is intended for direct mounting onto a contactor.
Trip Class and Release Design
The CLASS 10 trip class means the relay will trip within 10 seconds at 7.2× the set current, a standard for protecting standard induction motors during start-up. The overload release is thermal (bimetal) type, providing an inverse-time characteristic that tracks motor heating. The auxiliary switch is integrated into the relay body.
Switching Capacity by Voltage
The auxiliary contacts are rated for specific switching capacities depending on the control voltage: 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 others. These ratings define the maximum current the auxiliary contacts can safely interrupt at the given voltage — critical for sizing the control circuit load.
Environmental and Mechanical Ratings
The relay is rated for operation from -40 to +70 °C, with storage and transport tolerance from -55 to +80 °C. Temperature compensation is active from -40 to +60 °C, ensuring the trip curve remains accurate across the working range. The MTTF under high demand is rated at 2,280 years, reflecting the reliability of the electromechanical design.
Mounting and Connection
Mounting is via contactor mounting — it snaps directly onto the matching Siemens contactor, eliminating separate DIN-rail space. The fastening method is contactor mounting, and the mounting position is any orientation. The spring-loaded terminals accept 2 × (0.5 to 2.5 mm²) solid or stranded wire. A 3 mm diameter screwdriver is specified for the terminal screws.