What it is and what it does
The Siemens 3RT7025-1AM00 is a 3-pole S0-frame contactor from the SIRIUS family, designed for switching motor loads in control panels. It carries three normally-open main contacts and is rated for AC-3 duty up to 690 V, which covers most 400 V and 480 V motor circuits in industrial distribution. The contactor mounts on a 35 mm DIN rail per DIN EN 50022, with a width of 45 mm that fits standard panel layouts. Side-by-side mounting is permitted without derating, so you can pack multiple units on a rail for multi-motor groups.
Key ratings and what they mean for fit
The AC-3 maximum operating voltage of 690 V means this contactor can switch three-phase induction motors on 400 V, 480 V, or 600 V systems without exceeding the insulation voltage rated value of 690 V. The degree of pollution 3 rating confirms it handles conductive dust and humidity found in typical industrial enclosures. Auxiliary contact reliability is specified for PLC control at 17 V and 5 mA, so the built-in auxiliary contacts can directly signal a 24 VDC PLC input without an interposing relay. The auxiliary contact ratings at 230 V (6 A), 400 V (3 A), and 690 V (1 A) cover signal switching for most control circuits. For short-circuit protection, Type 1 coordination requires a 63 A gL/gG fuse, while Type 2 coordination (which limits contact damage) calls for a 25 A gL/gG NH 3NA fuse. These values are what you give the panel builder for the branch circuit design. The DC coil consumes 0.82 W during pickup and 0.24 W holding, so the control transformer or 24 VDC supply only needs to budget about 1 VA per contactor. Surge voltage resistance of 6 kV matches the impulse withstand requirement for industrial control panels per IEC 60947.
Where it fits in a panel
The 45 mm width and 91 mm depth let it fit in shallow enclosures where deeper contactors would hit the gland plate. Screw-type terminals on both main and auxiliary circuits accept 2x (0.5 to 1.5 mm²) solid or stranded, or 2x (0.75 to 2.5 mm²) — no ferrule needed for solid wire, but use ferrules on stranded for reliable connection. Mounting position is flexible: +/-180° rotation on a vertical surface, and can be tilted forward/backward by +/-22.5°. This helps when routing wires in tight cabinets or when the contactor sits on a swing frame.