Siemens SIRIUS 3RT1024-1AL24 — Power Contactor, S0 Frame, 24 VDC Coil
It carries a 24 VDC coil and is rated for AC-4 duty at 12.5 A at 400 V — that's the category for reversing or inching motor starts where the contactor makes and breaks the motor current at full load, not just the inrush.
Motor Duty and Coordination
For resistive loads (AC-12), the contactor handles up to 10 A. Type 1 coordination requires a 63 A gL/gG fuse; Type 2 coordination requires 25 A. That's the short-circuit protection the contactor needs to survive a fault without welding its main contacts — the 25 A fuse for Type 2 keeps let-through energy low enough that the contactor can be re-energised after clearing the fault. The auxiliary contact block carries 2 N/O instantaneous contacts, rated at 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V — enough for feedback to a PLC or to seal in the coil circuit.
Main circuit terminals accept screw-type connections: solid or stranded wire from 1 to 6 mm² (2x 1–2.5 mm², 2x 2.5–6 mm², max 2x 10 mm²). The coil terminals accept finer wire: 0.5 to 4 mm² (2x 0.5–1.5 mm², 2x 0.75–2.5 mm², max 2x 0.75–4 mm²). AWG equivalents are 2x 16–12 and 2x 14–10 for the main circuit, 1x 8 maximum. Side-by-side mounting is allowed with a 6 mm gap to the side, which means you can pack contactors tightly on the rail without derating, as long as the ambient stays within the -25 to +60 °C range.