What it is and where it fits
The Siemens 3RT1025-3AV60 is a SIRIUS power contactor in the S0 frame size, with three normally-open main contacts. It mounts via screw or snap-on onto 35 mm DIN rail per EN 50022, so it drops into any standard panel rail without adapters. The screw-type terminals on the main circuit accept up to 2x 10 mm² stranded or 1x 8 AWG, which covers most motor branch wiring up to 7.5 kW.
Ratings that decide the fit
At AC-2 duty (slip-ring motors, wound-rotor) it's rated 7.5 kW at 400 V — that's the motor power it can switch under moderate inrush. For AC-4 (plugging, inching, reversing) the current rating is 15.5 A at 400 V, which is the figure to size against your motor's locked-rotor current during frequent reversals. Pollution degree 3 means it's built for industrial enclosures where conductive dust or condensation is expected. Type 1 coordination requires a 63 A gL/gG fuse upstream; type 2 coordination calls for 25 A. That's the selectivity headroom you need for the branch circuit — type 2 keeps the contactor reusable after a short, type 1 may damage it.
Integration notes
The S0 frame is 45 mm wide, 85 mm tall, 90 mm deep — fits a standard 45 mm DIN cell. Side-by-side mounting is allowed, so you can gang multiple contactors without spacing. Front IP20 means finger-safe; the terminals themselves are IP00, so keep live parts behind a panel door or cover. Operating temperature range is -25 to +60 °C, which covers most indoor industrial environments.