What it is and what it does
The Siemens 3RU2116-1GC0-ZW96 is a SIRIUS thermal overload relay in the compact S00 frame size, designed to protect motors against overcurrent and phase-failure conditions by monitoring the motor current and tripping the associated contactor when an overload is detected. Its CLASS 10 trip characteristic means it will trip within 10 seconds at 7.2× the set current, which is the standard protection class for general-purpose induction motors — fast enough to prevent winding damage during a locked-rotor event, but not so fast that it nuisance-trips on normal starting inrush. The relay mounts directly onto a contactor (fastening method: contactor mounting), so the entire motor starter package — contactor plus overload — occupies the same DIN-rail footprint as the contactor alone.
Key ratings and what they mean for fit
Rated insulation voltage is 690 V. Motor power ratings at common voltages: 2.2 kW at 400 V, 3 kW at 500 V, and 4 kW at 690 V — these are the maximum motor sizes the relay can protect at those supply voltages when wired in a standard three-phase configuration. The integrated auxiliary switch provides signal feedback across multiple control voltages: 2 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V — this covers the common control-circuit voltages found in North American and European panels, so the trip signal can be wired directly to a PLC input or a status lamp without an interposing relay. Spring-loaded terminals on the main current circuit accept 2× (0.5 to 2.5 mm²) solid or stranded wire — no screwdriver needed for the power connections, which speeds up panel wiring and eliminates the risk of loose screw terminals on high-vibration installations.
Where it goes in the panel
Size S00 frame: 45 mm wide, 87 mm tall, 70 mm deep. Mounting position is any orientation, which simplifies panel layout when space is tight or the enclosure is mounted vertically or horizontally. Temperature compensation is active from -40 to +60 °C, so the relay maintains its trip accuracy even when mounted near heat-generating components like contactors or drives inside a sealed cabinet.
Lifecycle and sourcing reality
The -ZW96 suffix indicates a special version with the "Tripped" message marking on the front face — functionally identical to the standard 3RU2116-1GC0 but with the visual indicator pre-printed for quick status identification on the panel door or in a high-density starter bank.