The Siemens 3RU2116-1JB0-ZW96 is a SIRIUS Size S00 thermal overload relay with an integrated auxiliary switch and a dedicated "Tripped" message output. It's the part that sits between the contactor and the motor, watching current and protecting the winding from sustained overcurrent. The trip class is CLASS 10, meaning it will open the circuit within 10 seconds at 7.2× the full-load current setting — fast enough for standard motor starting, not so fast that it nuisance-trips on a normal start.
Ratings and what they mean for fit
Rated insulation voltage is 690 V, which covers 400 V and 480 V systems with headroom. The auxiliary contact ratings tell you what the signal side can handle: 2 A at 24 V, 2 A at 230 V, and 1 A at 400 V. That's enough to drive a PLC input or a small relay coil. The power dissipation per pole is 2.2 W, so three poles running at full load dump about 6.6 W into the enclosure — factor that into your panel thermal budget. The overload relay mounts directly onto the contactor, which saves DIN-rail space and keeps the power wiring short. Size S00 is the smallest SIRIUS frame, so it pairs with the S00 contactor range. The screw terminals accept 2×(0.5…1.5 mm²) or 2×(0.75…2.5 mm²) solid or stranded wire, and the screwdriver spec is Pozidriv PZ2 with a 5–6 mm shaft diameter.
Environmental and compliance
Operating temperature range is -40 to +70 °C, with storage and transport from -55 to +80 °C. Temperature compensation is active from -40 to +60 °C, so the trip curve stays accurate across the working range. The substance prohibition date of 10/01/2009 indicates RoHS compliance — the part was designed to meet the 2009 deadline for restricted substances.