Soft starter for motor starting duty
Thyristor-based output stages handle the inrush; the unit carries an adjustable current limitation and integral motor overload protection. At 40 °C ambient it is rated for 356 A, derating to 315 A at 50 °C and 280 A at 60 °C. The control supply is 230 V at 50 or 60 Hz. Mounting is screw-fixing to a vertical surface. With the additional fan fitted, the unit can be rotated ±90° or tilted ±22.5° front-to-back; without the fan, rotation and tilt are limited to ±10°. Clearance requirements: 100 mm above, 75 mm below, and 5 mm at the sides.
Current ratings and thermal derating
Above 40 °C, derate linearly: 315 A at 50 °C, 280 A at 60 °C. The minimum load is 20 % of the rated current — below that, the thyristor firing angle may not produce a clean waveform. Insulation voltage is rated 600 V, pollution degree 3 per IEC 60947-4-2.
Wiring and connection
Main power connections accept busbar or cable. For the main current circuit, the front clamping point accepts 3/0 to 600 kcmil, the back clamping point 250 to 500 kcmil, and using both clamping points together 2/0 to 500 kcmil. Stranded cable: 70 to 240 mm²; finely stranded: 50 to 240 mm². Solid auxiliary wiring: 2x (0.5 to 2.5 mm²). Maximum wire length from the soft starter to the motor is 300 m.