SIRIUS S0 power contactor for motor and resistive loads
The Siemens 3RT1024-1AL24-ZW96 is a SIRIUS power contactor in the S0 frame size, designed for switching motor and resistive loads in industrial control panels. It mounts via screw or snap-on onto 35 mm DIN rail per EN 50022, fitting a 45 mm wide footprint. The 24 VDC coil draws its holding current from a standard 24 V supply; the contactor is rated for 7.5 kW at both 500 V and 690 V, making it suitable for 400 V class motors with headroom for higher line voltages. The front face carries IP20 protection; the terminals are IP00, so the contactor expects enclosure protection for the wiring zone.
Ratings and what they mean for your circuit
The AC-4 rating at 400 V is 12.5 A — this is the switching current for reversing or inching duty where the contactor makes and breaks motor current at standstill or low speed. For AC-2 duty (slip-ring motors, moderate overloads) the same contactor handles 5.5 kW at 400 V. The resistive-load rating (AC-12) is 10 A maximum. Pollution degree 3 means the contactor is rated for industrial environments with conductive dust or occasional condensation; no additional conformal coating is required for typical panel conditions. The mechanical life is 10 million operations, so in a cycling application (conveyor, pump start/stop) the contactor will outlast most electromechanical relays in the same circuit.
Panel integration notes
The S0 frame occupies 45 mm width, 85 mm height, and 140 mm depth — the depth is the dimension from the mounting rail to the furthest projection (typically the coil terminals or arc chamber). Side-by-side mounting is permitted without derating, with a 6 mm gap to adjacent devices. The screw-type main terminals accept 2x (1 to 2.5 mm²) stranded or 2x (2.5 to 6 mm²) solid, up to a maximum of 2x 10 mm². The auxiliary contact block (2 instantaneous contacts) uses smaller terminals: 2x (0.5 to 1.5 mm²) solid or 2x (0.75 to 2.5 mm²) stranded, max 2x (0.75 to 4 mm²). For type 2 coordination (no damage to the contactor under short circuit), use a gL/gG fuse rated 25 A; for type 1 coordination (contactor may need replacement after fault), a 63 A fuse is permitted.