What it is and what it does
The Siemens 3RT1025-1AK60-ZW97 is a SIRIUS power contactor in size S0, designed for switching three-phase motor loads in control panels. It mounts via screw or snap-on onto a 35 mm DIN rail per EN 50022, with a 45 mm width that fits standard panel layouts. Rated for 7.5 kW at 400 V in AC-2 duty (slip-ring motor starting), and 11 kW at 690 V, this contactor handles pump, fan, and compressor loads up to its frame rating. For reversing or inching duty (AC-4), it carries 15.5 A at 400 V — a figure that governs contact life in frequent-switching applications. Auxiliary contacts are rated 10 A at 24 V, 6 A at 230 V, and 0.3 A at 220 V, covering PLC-level signal switching and control circuit isolation. The IP20 front and IP00 terminal area mean the body is finger-safe when panel-mounted; wiring terminations require enclosure protection.
Integration notes
The 45 x 85 x 91 mm (W x H x D) footprint fits a standard S0 contactor slot. Side-by-side mounting is permitted with 6 mm spacing, so multiple contactors can pack tightly on a DIN rail without derating — useful for multi-motor MCC sections. Screw terminals on the main circuit accept 2x (1 to 2.5 mm²) solid or stranded, up to 2x 10 mm² max. The auxiliary circuit uses smaller terminals: 2x (0.5 to 1.5 mm²) solid. For Type 2 coordination (no-weld on fault), specify a 25 A gL/gG fuse upstream; for Type 1 (replace after fault), a 63 A fuse is allowed. Operates from -25 to +60 °C ambient, with a maximum altitude of 2000 m. The pollution degree 3 rating means it tolerates conductive dust and humidity typical of industrial enclosures — no need for sealed cabinets in clean environments, but a minimum IP54 panel is wise in dirty plants.