What it is and what it does
The Siemens 3RH1140-1BF40-0AA6 is a SIRIUS auxiliary contactor in frame size S00, carrying four normally-open instantaneous contacts and a 110 V DC coil. It is designed to switch control signals and auxiliary loads in motor control centers and panel builds — not to switch main motor current, but to extend the I/O of a contactor or relay base. The 110 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. Contact reliability is rated at one incorrect switching per 100 million operations at 17 V, 1 mA, which covers dry-contact PLC inputs and low-energy signal paths.
Contact ratings and what they mean for the panel
The contacts are rated for switching at several voltage levels: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, 2 A at 500 V, and 1 A at 690 V. These are the thermal current ratings for the contact set — they define the maximum continuous current the contacts can carry at each voltage. For a 24 V DC control circuit, the 10 A rating gives ample headroom for pilot lights, solenoid valves, and PLC input modules. At 690 V, the 1 A rating still handles most auxiliary transformer and indicator loads. Mechanical life is rated at 30 million operations typical, which aligns with the S00 frame's duty cycle for auxiliary switching in high-cycling applications like conveyor interlocking or packaging machinery.
Integration into the panel
Mounting is via screw or snap-on onto a DIN rail, with the mounting position allowing +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward. The footprint is 45 mm wide, 57.5 mm tall, and 72 mm deep — a compact S00 envelope that fits standard 45 mm DIN-rail spacing. The front face carries IP20 protection, so it is safe for open panel builds where accidental finger contact is a concern. Wire sizing for the auxiliary contacts accepts 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or 2x 4 mm² solid, plus the AWG equivalents. The spring-cage or screw terminals (fastening method is screw and snap-on) handle the range cleanly — strip length and ferrule choice follow standard panel practice.
Environmental and compliance
Operating temperature spans -25 to +60 °C, with storage and transport from -55 to +80 °C. Shock resistance is 10g for 5 ms and 5g for 10 ms, and pollution degree is rated 3 (conductive pollution or dry non-conductive pollution that becomes conductive due to condensation). Surge voltage resistance is 6 kV. The substance prohibition date of 07/01/2006 indicates RoHS compliance per the EU directive effective from that date.