Siemens 3RT2025-1BA40 SIRIUS Power Contactor, Size S0, 24 VD

The 24 VDC coil pulls in at 0.8 of rated voltage (about 19.2 V) and drops out with a 15–18 ms delay, which is fast enough for most interlocking circuits but not a safety-rated instant drop. The main contacts are rated for AC-1 resistive loads up to the contactor's full thermal current and AC-3 motor switching at 400 V at 3 A — that's roughly a 1.1 kW motor at 400 V three-phase. AC-4 (inching/jogging) is limited to 300 operations per hour versus 1 000 for AC-3, so if your application cycles the contactor under load repeatedly, this part is not the right choice; you'd want a higher-rated frame or a dedicated reversing pair. Wire range accepts 1–10 mm² solid or stranded on the main contacts, with auxiliary terminals taking 2x 0.5–1.5 mm² or 2x 0.75–2.5 mm². That covers most control wiring up to 10 AWG solid. The screw-type terminals are standard for panel builders — no special tooling needed. The mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward, which gives flexibility in tight enclosures but keep the arcing clearance of 10 mm upwards and 6 mm sideways per the spec.