What it is and what it does
The Siemens SIRIUS 3RT1325-1AU60 is a size S0 power contactor with four poles, all normally open, for switching motor loads in control panels. It is rated for 7.5 kW at 400 V in AC-2 duty (slip-ring motors, reversing starts), and carries a maximum AC-12 operating current of 10 A for resistive loads. Mechanical life is rated at 10 million cycles.
Mounting and integration
Mounts via screw or snap-on onto 35 mm DIN rail per EN 50022. Dimensions are 61 mm wide, 85 mm high, 91 mm deep. Side-by-side mounting is permitted with a 6 mm gap at the side. The front face carries IP20 protection; the terminal area is IP00, so live parts are exposed at the wiring point — keep panel gland plates and finger guards in mind during layout.
Wiring and coordination
Main circuit wiring uses screw-type terminals accepting solid or stranded conductors: 2x (0.5...1.5 mm²), 2x (0.75...2.5 mm²), max 2x (0.75...4 mm²) for the smaller range, and 2x (1...2.5 mm²), 2x (2.5...6 mm²), max 2x 10 mm² for the larger. AWG equivalents are 2x (20...16), 2x (18...14), 1x 12. For type 2 coordination (no weld after fault), use a gL/gG fuse rated 25 A; for type 1 coordination (device may be damaged but safe), use 63 A. Pollution degree 3 applies, so the contactor is suited for industrial environments with conductive contamination.