1524 A at 40 °C — the derating curve sets the real limit
The 3RW4457-2BC44: That figure drops to 1351 A at 50 °C and 1200 A at 60 °C — the derating is linear with temperature, so the panel ambient inside the enclosure, not the motor room temperature, governs the continuous current you can pass through the thyristors. Operating frequency is 50/60 Hz, control voltage 230 V at both line frequencies.
Integrated bypass and inside-delta wiring
An integrated bypass contact system closes after the start ramp, shunting the thyristors and eliminating semiconductor conduction losses during run. This means the 1524 A rating applies to the bypass path, not just the SCRs — the thermal load on the enclosure drops once the motor is at speed. Inside-delta circuit wiring is supported, which reduces the line-side current to 58% of the motor full-load current in a delta-connected motor. For a 1524 A motor FLC, the soft starter sees roughly 884 A per phase on the line side — a significant saving on upstream cable and contactor sizing.
Mounting, clearances, and conductor terminations
Screw fixing to a vertical mounting surface, with ±90° rotation and ±22.5° tilt forward/backward allowed. Dimensions: 640 mm height, 510 mm width, 290 mm depth — plan the enclosure backplate accordingly. Clearance requirements: 100 mm above, 75 mm below, 5 mm at the sides. These are the minimum air gaps for natural convection cooling and arc-flash containment per the installation guide. Main current circuit connection is via busbar (not cable lugs). Auxiliary and control circuits use spring-loaded terminals — no screw torque check needed on those.
Protection and control features
Motor overload protection is built in — no separate overload relay required. Adjustable current limitation lets you set the start current between 100% and the rated current ceiling, matching the motor inrush to the supply capacity. Minimum load detection threshold is 8% of the rated current — below that the soft starter may not detect the motor is connected. External reset input allows remote fault recovery without opening the panel door. A local display shows fault codes. Intrinsic device protection covers the thyristors against over-temperature and over-current. The pollution degree is 3 per IEC 60947-4-2 — suitable for industrial environments with conductive dust or occasional condensation.