The Siemens 3RH1140-2BB40-ZW98 is a SIRIUS auxiliary contactor in size S00, carrying four normally-open instantaneous contacts. The 24 V DC coil draws 3.2 W for both closing and holding, so the power supply sizing is straightforward — no inrush spike to budget for. Contacts are rated 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V, which covers most control-circuit switching in a 400 V panel. The 45 mm width and screw-and-snap-on mounting mean it clips directly onto a DIN rail alongside a SIRIUS contactor or motor starter, sharing the same bus system.
Mounting and integration
Screw and snap-on mounting onto a DIN rail. The 45 mm width and 73 mm depth fit the standard SIRIUS S00 footprint — it occupies one slot in a motor-starter assembly or a standalone auxiliary block. Mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward, so it adapts to tight enclosures. IP20 on the front means it is protected against finger contact but needs an enclosure for washdown environments.
Contact ratings and switching capability
Four instantaneous NO contacts — no delayed, lagging, or make-before-break variants on this order code. Rated operational currents: 10 A at 24 V, 1 A at 110 V, 0.27 A at 220 V, 6 A at 230 V, 3 A at 400 V, 2 A at 500 V, and 1 A at 690 V. The 6 kV rated surge voltage resistance gives confidence for switching in industrial networks with transient exposure. Contact reliability is specified as one incorrect switching operation per 100 million at 17 V, 1 mA — a solid figure for PLC-level signal switching.
Termination and wiring
Screw terminals accept 2x (0.25 to 2.5 mm²) solid or stranded conductors, or 2x (24 to 14 AWG). The dual-conductor capacity is useful for daisy-chaining control voltage across multiple devices without extra terminal blocks. Strip length and torque values follow standard SIRIUS practice for size S00.