The Siemens 3RT1025-1AG60 is a SIRIUS power contactor in size S0, rated for motor switching at 7.5 kW in AC-2 duty at 400 V (slip-ring motors, wound-rotor loads) and 15.5 A in AC-4 duty at 400 V (plugging, inching, reversing).
Side-by-side mounting is allowed — no gap needed between contactors, which tightens the row on a crowded gland plate. That depth matters when the enclosure back wall is tight against a busway or cable tray. Main terminals accept solid wire up to 2x 4 mm² or stranded up to 2x 10 mm²; auxiliary terminals handle 2x 2.5 mm² solid or 2x 4 mm² stranded. Screw-type terminals on both circuits — no cage-clamp, so torque the screws to the manufacturer's spec on the nameplate.
Type 2 coordination (no-weld after fault) calls for a 25 A gL/gG fuse upstream; Type 1 coordination (welding allowed but no fire) needs a 63 A gL/gG fuse. That's the selectivity headroom for a panel designer sizing the branch circuit.
