The Siemens SIRIUS 3RH1140-1VB40 is a coupling relay designed for switching auxiliary circuits in control panels. It carries a 24 V DC coil, four normally-open (NO) instantaneous contacts, and is rated to switch 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V (AC duty). The coil holds at 1.4 W DC, with a pickup voltage of 0.85 x rated value and dropout at 1.85 x rated value — meaning it pulls in reliably at 20.4 V and drops out above 44.4 V, a wide hysteresis that prevents chatter on sagging supplies.
The 3RH1140-1VB40 fits the SIRIUS S00 contactor footprint — 45 mm wide, 57.5 mm high, 72 mm deep — and mounts via screw or snap-on onto a DIN rail. Wire terminals accept solid conductors: 2x 0.5–1.5 mm², 2x 0.75–2.5 mm², or 2x 4 mm².
Ratings in context
Shock resistance is 10g for 5 ms and 5g for 10 ms, covering most industrial vibration profiles.