What it is and what the key ratings mean
The Siemens 3RU2116-1CC0-ZW97 is a SIRIUS thermal overload relay, Size S00, designed for motor protection in control panels. Its CLASS 10 trip characteristic means it will trip within 10 seconds at 7.2× the set current — fast enough to protect standard induction motors during a stall or locked-rotor condition without nuisance tripping on normal starting transients. Rated for a main circuit voltage up to 690 V at 50-60 Hz, this relay carries a note for message "Tripped" — a local visual and electrical indication that the overload has operated, which is wired into the control circuit to signal a fault condition to the PLC or HMI. Switching capacity varies by control voltage: 2 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V. These are the ratings for the integrated auxiliary switch contacts, not the main power path — they drive the trip signal back to the controller.
Mounting and integration
Mounts directly onto a contactor via the contactor mounting fastening method — no DIN rail required, saving panel space. The Size S00 footprint (45 mm wide, 87 mm tall, 70 mm deep) fits the standard SIRIUS S00 contactor range. Any mounting position is permitted, and spring-loaded terminals accept 2× (0.5 to 2.5 mm²) solid or stranded wire. The integrated auxiliary switch design eliminates the need for a separate add-on block for the trip signal, reducing component count and wiring. Temperature compensation is active from -40 to +60 °C, keeping the trip curve stable across the operating range.
Lifecycle and sourcing reality
Compliance documentation includes RoHS substance prohibitance dated 10/01/2009. The relay carries an MTTF of 2,280 years under high-demand rate — a reliability figure that reflects the thermal-mechanical design's inherent robustness, not a service-life guarantee.