The Siemens 3RT1025-3AV00 is a SIRIUS power contactor in size S0, carrying three normally-open main contacts. It uses screw-type terminals for the main current circuit and mounts via screw or snap-on onto 35 mm DIN rail per EN 50022. At 45 mm wide and 90 mm deep, it fits a standard panel slot for this frame size.
Ratings and what they mean for fit
Rated for AC-2 duty at 400 V at 7.5 kW and AC-4 at 400 V at 15.5 A — the AC-2 figure governs motor starting with moderate overload, while AC-4 covers plugging and inching where the contactor makes and breaks stalled-rotor current. For resistive loads (AC-12), it handles 10 A. The 50 Hz coil operates across 0.8 to 1.1 times rated voltage, so a 400 V coil holds in at 320 V and picks up reliably at 440 V. Mechanical endurance is rated at 10 million operating cycles, which suits high-duty applications like conveyor indexing or pump cycling. Pollution degree 3 means it's rated for conductive pollution in industrial enclosures — no special coating needed for typical panel environments. Ambient operating range is -25 to +60 °C, with a maximum installation altitude of 2 000 m. The front face carries IP20 protection; the terminals themselves are rated IP00, so the contactor needs enclosure protection against accidental contact. Side-by-side mounting is permitted with a 6 mm clearance to adjacent devices, which saves rail space in dense panels.
Termination and wiring
Main circuit terminals accept solid or stranded conductors: 2x (0.25 to 2.5 mm²) and 2x (1 to 2.5 mm²) or 2x (2.5 to 6 mm²), with a maximum of 2x 10 mm². AWG equivalents are 2x (16 to 12), 2x (14 to 10), or 1x 8. For type 2 coordination (no damage to the contactor under short circuit), the required fuse is 25 A gL/gG; for type 1 coordination (contactor may need replacement), 63 A gL/gG.