The Siemens SIRIUS 3RT1024-1BB40-ZW97 is a size S0 power contactor rated for 24 VDC coil control, delivering 10 A in AC-12 duty (resistive loads) and switching motor loads up to 5.5 kW under AC-2 at 400 V.
The 24 VDC coil draws 10 A at rated value and holds at 5.4 W; dropout occurs below the minimum holding threshold, so verify your control supply stays above 18 V under load. For motor switching, the AC-2 rating of 5.5 kW at 400 V covers slip-ring motors and moderate-duty starts, while the AC-4 rating of 12.5 A at 400 V handles reversing and inching duty. At 500 V and 690 V the contactor is rated for 7.5 kW each, which is useful for 690 V delta-connected motors in European installations.
The screw terminals accept 2x 0.5–1.5 mm² solid or 2x 0.75–2.5 mm² stranded, with a maximum of 2x 4 mm² solid for the main circuit — useful when paralleling conductors for higher ampacity.