The Siemens SIRIUS 3RT1024-1AH24 is a power contactor in the S0 frame size, designed for switching motor loads in control panels. It mounts via screw or snap-on onto 35 mm DIN rail per EN 50022, fitting a standard panel layout. The 24 VDC coil is rated for continuous duty across the operating temperature range of -25 to +60 °C.
Key ratings and what they mean for fit
The AC-4 rating of 12.5 A at 400 V governs reversing or inching duty — the contactor's ability to break motor starting current repeatedly. For AC-2 duty (slip-ring motors), it carries 5.5 kW at 400 V. At 690 V, the contactor is rated for 7.5 kW, and at 500 V also 7.5 kW, covering common European and North American motor voltages. The AC-12 rating of 10 A applies for resistive loads in control circuits. Type 1 coordination requires a 63 A gL/gG fuse upstream; Type 2 coordination (no damage to the contactor under fault) needs a 25 A gL/gG fuse. This matters when designing for selectivity in a motor control center — the fuse size directly affects the upstream breaker coordination.
Panel integration notes
The S0 frame occupies 45 mm width on the DIN rail, with a depth of 140 mm and height of 85 mm. Side-by-side mounting is permitted, with a 6 mm clearance required at the side for heat dissipation. The front face carries IP20 protection; the terminals themselves are IP00, so the panel enclosure provides the overall ingress protection. Screw terminals accept solid conductors from 2x 0.5 mm² up to 2x 4 mm², and stranded conductors up to 2x 10 mm².