Rated current and thermal ceiling
The 3RW4455-2BC36 is rated 1200 A at 40 °C ambient — this is the continuous motor starting duty ceiling. Derate to 1065 A at 50 °C and 954 A at 60 °C if the panel ambient runs hot. The 690 V rated insulation voltage gives headroom on 400/480 V systems without forced derating.
Integrated bypass and inside-delta wiring
An integrated bypass contact system is built in — no external bypass contactor to wire, which saves panel space and reduces the component count by one. The soft starter also supports inside-delta circuit connection, which reduces the line current by 58% compared to standard in-line wiring; the main current circuit uses busbar connection, and the stranded cable range is 70–240 mm².
Mounting and panel integration
Mounting is screw fixing — not DIN-rail — so the panel backplate must be drilled for the 640 mm height, 510 mm width, and 290 mm depth footprint. The mounting position allows vertical surface with +/-90° rotation and +/-22.5° tilt front/back. Pollution degree 3 per IEC 60947-4-2 means it tolerates conductive dust in industrial enclosures without additional conformal coating.
Protection and control features
Motor overload protection is integrated — no separate overload relay needed, which simplifies the control circuit. Adjustable current limitation lets you set the starting current between 100% and 400% of motor FLA. The thyristor power section provides phase-angle firing for smooth acceleration ramps. A display shows fault signals locally, and an external reset input allows remote clearing after a trip. The minimum load is 8% of rated current, so it handles lightly loaded motors without instability.