The Siemens SIRIUS 3RH1344-1AU00-0KA0 is an auxiliary contactor in the S00 frame size, carrying 4 instantaneous normally-open contacts. It is designed for signal switching and control-circuit isolation inside motor starter assemblies or PLC output cabinets, not for direct motor loads — the contacts are rated for the control voltages listed below, not AC-3 duty. Screw and snap-on mounting onto DIN rail is standard, with a 45 mm width that fits standard panel cutouts. The mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward, giving flexibility in tight enclosures. Contact reliability is specified at one incorrect switching operation per 100 million cycles at 17 V and 1 mA — meaning it handles dry-circuit (low-energy) signal switching reliably, not just power-level pilot duty. This matters for PLC inputs or safety relay chains where contact wetting current is minimal.
Ratings and what they mean for fit
The 4 instantaneous NO contacts (no delayed, lagging, or make-before-break variants on this order code) each carry rated currents that drop sharply with voltage: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, and 1 A at 690 V. These are the thermal continuous currents the contacts can handle at the respective AC voltages, not motor-starting ratings. For a 24 VDC PLC output interposing relay, the 10 A rating gives generous headroom; at 400 V control circuits, the 3 A limit governs. Surge voltage resistance is 6 kV, which places it in the standard industrial control-panel insulation class for 400 V line-fed circuits. Pollution degree 3 means it is rated for conductive pollution environments typical of unsealed industrial enclosures — no additional conformal coating required for most factory-floor installations. Shock resistance is 10g for 5 ms and 5g for 10 ms, adequate for mounting on machine frames or conveyor sections that see vibration. The IP20 front protection means the contactor terminals are finger-safe from the front but not washdown-rated — keep it inside a cabinet, not on open panel doors.
Compliance and documentation
Substance prohibitance date is 07/01/2006, aligning with RoHS compliance. The SIRIUS series carries CE, UL, and CSA certifications standard for the brand — the 6 kV surge rating and pollution degree 3 support IEC 60947-5-1 compliance for control circuit devices.
Wire range accepted: 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or 2x 4 mm² solid — the screw terminals accept dual conductors, useful for daisy-chaining control voltage across multiple contactors in a row. Depth of 111 mm, height of 57.5 mm, and 45 mm width are the S00 standard footprint, so it replaces any S00 auxiliary contactor block on the same DIN-rail pitch without re-drilling.