Auxiliary contactor, SIRIUS, size S00, 24 VDC coil, 3 NO
The Siemens 3RH1131-1BB40-ZW96 is a SIRIUS auxiliary contactor in the S00 frame size, carrying three normally-open instantaneous contacts and a 24 VDC magnet coil. It mounts via screw or snap-on onto a DIN rail, with the front face rated IP20 for basic finger protection inside an enclosure. The coil draws 3.2 W during both closing and holding, so the power supply budget is flat — no inrush spike to size for.
Switching capacity and contact ratings
Contact ratings are given per the IEC utilization categories, with the 24 VDC rated value at 10 A. At 230 V the contactor switches 6 A; at 400 V it drops to 3 A; at 690 V it is rated for 1 A. For DC switching at 110 V the rating is 1 A, and at 220 V it is 0.27 A. These are the values to use when sizing for a specific load voltage — the 10 A figure at 24 V is the highest, but the derating curve above that is steep.
Mechanical endurance and contact reliability
Mechanical life is rated at 30 million switching operations typical. Contact reliability is specified as one incorrect switching operation per 100 million operations at 17 V, 1 mA — that is the low-energy threshold for dry-circuit signal switching. If you are switching logic-level signals, the contact metallurgy is designed for that regime.
Environmental and mounting flexibility
Operating temperature range is -25 to +60 °C; storage and transport range is -55 to +80 °C. The contactor can be mounted on a vertical surface with +/-180° rotation, and can be tilted forward or backward by +/-22.5° on that same surface. Shock resistance is 10g / 5 ms and 5g / 10 ms. Pollution degree 3 means it is suitable for industrial environments with conductive pollution or dry non-conductive pollution that becomes conductive due to condensation.
Wiring and termination
The auxiliary contact terminals accept solid conductors: 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), and 2x 4 mm². For AWG, the range is 2x (20 to 16), 2x (18 to 14), and 1x 12. Surge voltage withstand is rated at 6 kV. The contactor is designed for screw-type terminals, so torque values per the Siemens installation instructions apply.