What this star-delta assembly is and what it delivers
The Siemens 3RA2445-8XF32-1AG2 is a factory-assembled star-delta (wye-delta) contactor assembly from the SIRIUS S3 size family. It ships with two 3RT2045-1AG20 contactors and one 3RT2036-1AG20, plus the interlocking and timing kit, so you mount one unit instead of piecing together three contactors and a separate star-delta timer. Rated 75 kW at 400 V AC-3 (110 kW at 690 V), it handles the motor starting current for a 75 kW induction motor on a 400 V line — typical for pumps, compressors, and conveyors in industrial panels. That gives panel builders leeway in tight enclosures.
Coil voltage, terminals, and auxiliary contacts
The magnet coil and main current circuit both use screw-type terminals, accepting 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded, and AWG 10 to 1/0 for the main contacts. That covers most panel wiring practices. The assembly has three instantaneous contacts. No auxiliary switch is fitted as standard, and no bus communication module is included — this is a straightforward motor-starting assembly, not a networked soft-starter. The supplied RS assembly kit (order code 3RA2943-2C) provides the mechanical interlock and wiring links.
Environmental limits and vibration resistance
Vibration resistance is rated at 10.6 g for 5 ms and 6.3 g for 10 ms under AC shock — adequate for standard industrial machinery but not extreme continuous vibration.