What it is and what it does
The Siemens SIRIUS 3RT1025-1AP00-ZW97 is a power contactor in the S0 frame size, designed for switching motor loads and resistive loads in industrial control panels. It carries 3 normally-open main contacts and zero normally-closed main contacts, so it is a straight make-only device — no auxiliary break on the main poles. The contactor mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 50022, which is the standard for panel integration in European-spec cabinets.
Key ratings and what they mean for fit
The AC-12 maximum operating current is 10 A. AC-12 is the resistive-load category (heater banks, lighting), so this contactor is sized for general-purpose on/off switching up to that current. For motor duty, the AC-2 rating at 400 V is 7.5 kW, and the AC-4 rating (plugging/inching) at 400 V is 15.5 A — the AC-4 figure is the one to watch for reversing or jogging applications, since it governs contact wear under high inrush. The contactor is rated for a mechanical life of 10 million operations typical.
Dimensions and wiring
The S0 footprint is 45 mm wide, 85 mm high, and 91 mm deep — a compact size that fits standard 35 mm DIN-rail enclosures. Main circuit terminals are screw-type, accepting 2x (1 to 2.5 mm²) solid or 2x (2.5 to 6 mm²) stranded, with a maximum of 2x 10 mm². The auxiliary/control circuit terminals accept 2x (0.5 to 1.5 mm²) solid and 2x (0.75 to 2.5 mm²) stranded. Side-by-side mounting is allowed with 6 mm spacing to the side. The front face is IP20; the terminal area is IP00 (no finger-safe protection at the connection points).
Environmental and installation limits
Operating temperature range is -25 to +60 °C, which covers most indoor industrial environments. Maximum installation altitude is 2 000 m without derating. Pollution degree 3 means it is rated for conductive pollution in industrial atmospheres (condensation, light dust). The coil operates at 50 Hz with a voltage tolerance of 0.8 to 1.1 times rated voltage.