What it is and what it does
The Siemens SIRIUS 3RT1016-2BB42-ZW95 is a size S00 power contactor with a 24 VDC coil, rated for 10 A in AC-12 duty (resistive loads). It uses spring-loaded terminals on the main current circuit, so wiring is tool-less and vibration-resistant — no screw torque to verify, no loosening over time on a conveyor line. Mounts via screw or snap-on onto 35 mm standard mounting rail per DIN EN 50022. The 45 mm width and 73 mm depth fit neatly into a compact panel; side-by-side mounting is permitted, so you can gang several contactors without extra spacing.
Key ratings and what they mean
The AC-12 rating of 10 A is the resistive load limit — think heaters or incandescent lamps, not motors. For motor duty, the contactor is rated 4 kW at 400 V in AC-2 (slip-ring motors) and 8.5 A at 400 V in AC-4 (plugging/inching). That AC-4 figure is the one to watch for reversing or jogging applications: it governs the contactor's life under frequent switching. Coil consumption is 3.3 W both closing and holding, so the DC supply sees a constant draw — no inrush spike. The coil pickup voltage is 85% of rated (20.4 VDC) and the dropout is 1.1 times rated (26.4 VDC), meaning it holds in through a sagging bus but drops cleanly when the control signal goes away.
Where it goes in the panel
Spring-loaded terminals accept 2x (0.25... 2.5 mm²) solid or stranded, or 2x (24... 14 AWG). No screwdriver needed for the main circuit — strip to 8 mm, push in. The auxiliary terminals are also IP20 finger-safe, so the contactor can sit near the front of the enclosure without shock-risk covers. Degree of pollution 3 means it's rated for conductive dust and condensation — typical for a non-climate-controlled cabinet. Operating temperature range is -25 to +60 °C, and altitude limit is 2 000 m without derating.