The Siemens 3RU2116-1HC0-ZW97 is a SIRIUS thermal overload relay in Size S00, designed for direct mounting onto a contactor. It provides Class 10 motor protection, meaning it will trip within 10 seconds at 7.2× the set current — standard for general-purpose induction motors driving pumps, fans, and conveyors where a fast trip on locked rotor is needed without nuisance tripping on normal starts. Rated for main circuit voltages up to 690 V, this relay carries motor power ratings of 3 kW at 400 V, 4 kW at 500 V, and 5.5 kW at 690 V, with corresponding current ratings of 8 A at both 480 V and 600 V. The auxiliary contact block is integrated and rated for switching: 2 A at 24 V and 230 V, 3 A at 120 V, 1 A at 400 V, and lower currents at higher voltages (0.3 A at 60 V, 0.22 A at 110/125 V, 0.11 A at 220 V).
Mounting and integration
Mounts directly onto a contactor via the fastening method — no separate DIN-rail base required, which saves panel width. The S00 frame size keeps the footprint compact at 45 mm wide, 87 mm tall, and 70 mm deep. Spring-loaded terminals accept 2× (0.5 to 2.5 mm²) solid or stranded wire; use a 3 mm diameter screwdriver with a 3.0 × 0.5 mm tip for the terminal screws. Any mounting position is permitted, and the relay includes temperature compensation from -40 to +60 °C, so it maintains accurate trip characteristics even in a warm enclosure near the contactor.
Environmental limits
Operating temperature range is -40 to +70 °C; storage and transport range is -55 to +80 °C. The operating frequency is 50/60 Hz. The relay includes an integrated auxiliary switch and a thermal overload release design. The note on the component line reads "for message 'Tripped'" — this variant includes a signaling contact that changes state when the relay trips, providing a remote indication to a PLC or annunciator.