356 A at 40 °C — the continuous current that matters
The 3RW4075-2BB45: That 356 A is the continuous motor current it can handle without derating — above 40 °C the current drops to 315 A at 50 °C and 280 A at 60 °C, so the real-world ceiling depends on your enclosure's internal temperature. Thyristor-based design with adjustable current limitation — you set the inrush ceiling as a percentage of the motor FLA, which is the primary knob for controlling start torque and supply dip.
Mounting and wiring — screw-fixed, busbar-ready
This is a screw-fixing mount, not DIN rail — it bolts to the backplate with the Size S12 footprint (278 mm deep, 160 mm wide, 230 mm tall). The mounting position allows vertical surface installation with ±90° rotation and ±22.5° tilt front/back when using the optional fan; without the fan the tilt range narrows to ±10°. Main circuit termination accepts stranded cable 70–240 mm² or 2/0–500 kcmil, with busbar connection via front, back, or both clamping points. The max motor cable length is 300 m, which is adequate for most motor centers but may need an output reactor beyond that.
Environmental and protection ratings
Pollution degree 3 per IEC 60947-4-2 — rated for industrial environments where conductive dust or condensation is present. Operating temperature range -25 to +60 °C, storage -40 to +80 °C, so it can sit in an unheated warehouse or a hot panel without issue. Derating begins at 40 °C; above that, the current must be reduced per the derating curve. Minimum load is 20% of the rated current — below that the thyristor firing may not be reliable, so don't use it on a motor that's oversized relative to the load. Not configurable for inside-delta wiring; this is an in-line soft starter only.