Auxiliary contactor for control-circuit switching
The Siemens 3RH1140-1BB40-ZX95 is a SIRIUS auxiliary contactor with a 24 V DC coil and four instantaneous normally-open contacts, rated for 10 A at 24 V. It's built into the Size S00 footprint — 45 mm wide, 57.5 mm tall, 72 mm deep — and mounts via screw or snap-on onto DIN rail. The IP20 front protection means it's meant for enclosed panel use, not washdown zones.
What the ratings mean for your panel
The four NO contacts are instantaneous — no make-before-break or delayed switching here, so they close and open in step with the coil. Rated 10 A at 24 V DC covers most PLC output and relay interface loads; at 230 V AC it's still good for 6 A, and at 400 V AC it handles 3 A. The 6 kV surge voltage resistance (rated value) gives it a solid margin for industrial control panels where transient spikes are common. Coil holds at 24 V DC nominal, draws 3.2 W during both pick-up and hold — no inrush spike to budget for.