What it is and what it does
The Siemens 3RH1353-1AF00 is a SIRIUS auxiliary contactor — a compact switching block used to extend the control-circuit contacts of a main contactor or to build isolated logic circuits in a panel. It carries five instantaneous normally-open contacts and no normally-closed or delayed contacts, so it is a straight make-only device for signaling or interlock duties. Rated for 10 A at 24 V and 6 A at 230 V, with a 690 V breaking capability of 1 A, it covers most control-voltage levels in industrial panels. The contact reliability is rated at one incorrect switching per 100 million operations at 17 V, 1 mA, meaning it handles dry-switching of PLC inputs without nuisance failures. It mounts on DIN rail via the integrated snap-on mechanism or can be screwed directly to a panel backplate. The size S00 footprint (45 mm wide, 57.5 mm tall, 111 mm deep) is the smallest SIRIUS frame, saving rail space in dense cabinets.
Mounting and integration
Screw and snap-on mounting allows DIN rail clip or screw mount. Mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward. The conductor cross-section accepts up to 4 mm² solid or 2.5 mm² stranded on the main terminals — enough for control wiring up to the 10 A rating. IP20 on the front means it is protected against finger contact but not washdown; keep it inside a sealed enclosure in wet environments.
Environmental and compliance
This is a current-production part. Operating temperature range is -25 to +60 °C, and it withstands 10 g shock at 5 ms duration. Surge voltage resistance is rated at 6 kV, and the pollution degree is 3 (conductive pollution or dry non-conductive that becomes conductive due to condensation). RoHS compliance is indicated by a substance prohibition date of 07/01/2006.