Rated current and thermal derating — the real usable current
The 3RW4446-2BC34 is rated 617 A at 40 °C ambient. For a motor load pulling 500 A FLA, this starter holds headroom at 40 °C but at 60 °C you're at the limit — factor the ambient inside your enclosure when sizing. Insulation voltage is 690 V rated, operating frequency 50/60 Hz. The thyristor output stage is inside-delta wired — that means the soft starter sits in the delta legs of the motor, not in the line, reducing the per-phase current the SCRs carry compared to a standard in-line connection.
Mounting and integration — panel layout constraints
Mounting position allows a vertical surface with +/-90° rotation and +/-22.5° tilt forward/back. Fastening is screw fixing. Dimensions: 210 mm wide, 230 mm high, 298 mm deep. Clearance: 100 mm above, 75 mm below, 5 mm at the sides. Main power connections accept busbar or cable: stranded 70–240 mm², finely stranded 50–240 mm², or AWG 2/0–500 kcmil. The back clamping point takes 250–500 kcmil, the front 3/0–600 kcmil.
Protection and control features
Built-in motor overload protection and intrinsic device protection are standard. Adjustable current limitation lets you set the starting torque profile. Minimum load is 8% of the rated current — below that the soft starter may not detect the load correctly. External reset input is present, and a display shows fault signals. Maximum motor cable length is 500 m. Pollution degree 3 per IEC 60947-4-2 means it's rated for industrial environments with conductive pollution.