What this part is and what it does
The Siemens 3RU2116-0HC0-ZW97 is a SIRIUS thermal overload relay in the S00 frame size, designed for motor protection in control panels. It mounts directly onto a contactor — the fastening method is contactor mounting — and uses a thermal bimetallic release to protect against overload conditions. The integrated auxiliary switch provides a "Tripped" signal message, so the relay reports its state back to the control system without a separate auxiliary block.
Key ratings and what they mean for fit
Trip Class 10 means the relay will trip within 10 seconds at 7.2× the current setting — standard for protecting standard squirrel-cage induction motors during start-up. The rated insulation voltage is 690 V, which covers 400 V and 480 V line-to-line systems common in industrial distribution. The auxiliary contact ratings are given per voltage: 2 A at 24 V, 3 A at 120 V, 2 A at 230 V, 1 A at 400 V — these are the switching capacities for the signal circuit, not the main power path. The main current circuit connects via spring-loaded terminals accepting 2 × (0.5 to 2.5 mm²) solid or stranded wire, so no screw tightening is needed on the power connections.
Mounting and integration
Size S00 is the smallest SIRIUS frame — 45 mm wide, 87 mm tall, 70 mm deep. It mounts directly onto the matching S00 contactor, saving DIN-rail space. The mounting position is any orientation, which helps in tight enclosures. Operating temperature range is -40 to +70 °C, with temperature compensation active from -40 to +60 °C, so the trip curve stays accurate across the panel's ambient range. Storage and transport range extends to -55 to +80 °C.