What this soft starter delivers for a 37 kW motor line
The Siemens SIRIUS 3RW3454-0DC25 is a soft starter for standard applications, sized to ramp a 37 kW motor at 400–600 V in standard circuit configuration. At 40 °C ambient it carries 99 A continuous; at 50 °C that derates to 73 A, and at 60 °C to 61 A. Inside-delta wiring bumps the capacity to 55 kW at 40 °C, 110 A. That configuration is common when the motor windings are accessible and you want to reduce the starter current rating relative to the motor FLA. The control supply is 24 V DC, accepting AC or DC, and the main current circuit connects via busbar.
This unit mounts by screw fixing — no DIN rail clip. The footprint is 216 mm wide by 356 mm tall by 187 mm deep.