What it is and where it lands
The Siemens 3RT1034-1AN64 is a SIRIUS power contactor in size S2, rated for motor switching at 15 kW in AC-2 duty at 400 V and 18.5 kW at 500 V. It mounts via screw and snap-on onto 35 mm DIN rail per EN 50022, so it drops straight into a standard panel rail without adapters. The front face carries IP20 protection; the terminals are IP00, meaning the wiring zone expects enclosure protection from the panel itself.
Key ratings — what they mean for the panel
AC-2 at 400 V delivers 15 kW — that's the rating for slip-ring motor starting where the contactor makes and breaks under load. AC-3 at 400 V is the standard squirrel-cage motor duty; the part carries that at 1000 operations per hour max. AC-1 resistive load maxes at 1200 1/h. The mechanical life is typical 10 million operations, so it's built for high-cycle conveyor or pump panels. Pollution degree 3 means it tolerates conductive dust and humidity found in industrial enclosures without conformal coating.
Terminal and wiring reality
Screw-type terminals on the main circuit accept solid conductors up to 2x 4 mm² (max 2x 0.75–4 mm²) and stranded up to 2x 25 mm². That covers most motor feeds up to 18.5 kW without needing lug adapters. The auxiliary contact block wiring uses the same screw clamp, 0.5–2.5 mm² solid or stranded. Side-by-side mounting is allowed, so you can gang multiple contactors on the same rail without a gap — useful for grouping motor starters in a tight cabinet.