1351 A at 40 °C — derating drives the real-world current
The 3RW4456-6BC46: In a hot mill enclosure near the rolls, that derating curve sets the usable motor FLA — not the catalog number. Insulation voltage is 690 V rated, with a pollution degree 3 environment per IEC 60947-4-2. That means the creepage distances are sized for conductive dust and humidity — typical in steel and cement plants.
Integrated bypass and inside-delta wiring
The bypass contact system is integrated — once the motor is up to speed, the thyristors are shorted, eliminating heat dissipation from the power stack during run. That means the enclosure fan load is sized for the start duty cycle, not continuous conduction. Inside-delta circuit connection is supported, which reduces the current through the soft starter to 58% of the line current for a delta-wound motor. The 1351 A rating in inside-delta covers motors up to roughly 2300 A line FLA. Mounting position allows vertical surface with ±90° rotation and ±22.5° tilt front-to-back — useful when the panel layout forces the starter onto a side wall or angled subplate.
Active production — sourcing reality
Termination for the main current circuit is busbar connection, accepting 2/0... 500 kcmil or 70... 240 mm² stranded.