The Siemens SIRIUS 3RH1122-2KB40-ZW98 is a coupling relay for switching auxiliary circuits, built in the compact S00 contactor footprint. It carries a 24 V DC coil drawing 2.3 W holding power and is rated for AC-12 duty at 10 A, making it a direct fit for control-circuit isolation and signal-level switching inside a panel.
Mounting and integration
Mounts via screw or snap-on onto DIN rail. The 45 mm width and 60 mm height fit standard S00 contactor spacing; depth is 73 mm. Screw terminals accept 2x (0.25... 2.5 mm²) solid or stranded wire. The mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward, so it adapts to tight gland-plate layouts without derating.
Ratings and what they mean
The AC-12 10 A rating covers resistive and solid-state loads typical in auxiliary circuits — pilot lights, contactor coils, PLC outputs. For inductive AC loads at 230 V the relay is rated 6 A; at 400 V it drops to 3 A. DC switching is covered at 24 V (10 A), 110 V (1 A), and 220 V (0.27 A). The built-in varistor surge suppressor handles coil suppression, so no external free-wheel diode is needed for the magnet coil.