What this part is and where it lands
The Siemens 3RH1140-1AK20 is a SIRIUS auxiliary contactor in size S00, carrying four normally open (4 NO) instantaneous contacts with no delayed, lagging, or make-before-break switching — a straight-forward signal-follower for control circuits in motor starter assemblies or PLC output isolation. Rated operational current spans 10 A at 24 V up through 1 A at 690 V, with intermediate ratings at 110 V (1 A), 220 V (0.27 A), 230 V (6 A), 400 V (3 A), and 500 V (2 A) — covering the common control-voltage range from 24 VDC to 690 VAC. Contact reliability is specified at one incorrect switching operation per 100 million operations at 17 V, 1 mA — a dry-circuit rating that matters when the contactor is switching low-energy PLC signals rather than power loads. The 45 mm width and S00 footprint mean it drops into the same DIN-rail slot as a standard S00 contactor or overload relay, sharing the screw and snap-on fastening method for panel integration.
Mounting and environment
Mounts on DIN rail via screw and snap-on; the mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward — useful when the panel layout forces a non-standard orientation. IP20 on the front means finger-safe but not washdown-rated; keep it inside a closed panel. Pollution degree 3 (conductive pollution or dry non-conductive that becomes conductive) is typical for industrial control cabinets. Operating temperature range -25 to +60 °C; storage and transport handle -55 to +80 °C. Shock resistance 10g / 5 ms and 5g / 10 ms — fine for most fixed industrial machinery, not for mobile equipment.
Wiring and termination
Solid wire terminations accept 2x (0.5... 1.5 mm²), 2x (0.75... 2.5 mm²), and 2x 4 mm² — covers the typical control-circuit wire gauges from signal-level up to 4 mm² for longer runs. Surge voltage resistance rated at 6 kV.
Lifecycle and sourcing
Substance prohibitance per RoHS applies from July 1, 2006 — the part is RoHS-compliant for EU markets.