Rated current and thermal derating — the real-world capacity
The 3RW4436-6BC35: The 281 A rating at 40 °C is the baseline for matching the soft starter to the motor nameplate FLA, provided the enclosure ambient stays at or below 40 °C. For a panel sitting in a warm plant or near heat-generating gear, use the derated figure for the actual ambient — the thyristor junction temperature governs the safe operating envelope, not the 40 °C number. The operating frequency range of 50 to 60 Hz means the same unit works on either mains standard without adjustment.
Inside-delta wiring and thyristor section
This soft starter supports inside-delta circuit configuration, which lets the thyristors carry only the phase current rather than the line current — effectively reducing the required current rating of the power section when the motor windings are reconfigurable. The thyristor-based power stage has no mechanical contacts to wear, but the semiconductor junction temperature still sets the current limit; the derating curve above reflects that.
Mounting and panel integration
The unit measures 170 mm wide by 200 mm high by 270 mm deep and is secured by screw fixing. Mounting position allows a vertical surface with ±90° rotation and ±22.5° tilt front-to-back, which gives flexibility in dense panels — provided the clearance distances (100 mm upward, 75 mm downward, 5 mm at the side) are maintained for airflow and wiring access.