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 45 mm wide body mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 50022, making it a direct fit for standard panel layouts. Coil holding power is 5.4 W DC, and the contactor is rated for pollution degree 3, suitable for industrial environments.
Coil and motor ratings — what they mean for fit
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.
Coordination and protection
Type 2 coordination (no damage to the contactor on short circuit) requires a gL/gG fuse rated 25 A; Type 1 coordination (contactor may need replacement) allows a 63 A fuse. 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.