The Siemens 3RW3017-1BB14 is a SIRIUS soft starter in the Size S00 frame, rated 12.5 A at 40°C with a 110-230 VDC control supply. It includes an integrated bypass contactor, so once the motor reaches full speed the thyristors are shorted out — that eliminates heat dissipation from the power semiconductors during run and keeps the panel temperature rise under control.
That 1.5 A drop between 40 and 60 °C is about 12% — plan your panel layout so the soft starter isn't stacked directly above a heat source like a braking resistor or a drive. The minimum load is 10% of the rated current, so it handles small motors down to about 1.25 A without needing a dummy load.
Mounting position is vertical with ±10° tilt front-to-back and side-to-side. Clearance above the device is 60 mm, below is 40 mm, and 15 mm at the sides — that's the free-air space needed for the thyristor heat sink to work. The screw and snap-on mounting means you can clip it onto a DIN rail for initial placement, then screw it down for vibration resistance in a machine-tool panel.
Wiring and connections
Main current circuit terminals are screw-type, accepting 2x (0.25... 2.5 mm²) solid or stranded. Auxiliary and control circuit terminals are also screw-type, for 2x (20... 14 AWG). The front clamping point accepts 2x (16... 10 AWG). Maximum wire length to the motor is 300 m — beyond that, capacitive charging current from long cable runs can cause nuisance tripping on the soft starter's internal protection.