133 A at 40 °C — what that means for the motor line
The 3RW4426-3BC36 is a SIRIUS soft starter rated 133 A at 40 °C in standard duty. That current rating governs the maximum motor full-load amps it can ramp up and protect — size it for a motor drawing up to 133 A FLA and the thyristor stack handles the inrush without bypassing until the motor is up to speed. The integrated bypass contact system takes over after start, shunting the thyristors so they cool between starts — that's what lets this unit handle repeated starts without oversized heatsinks.
Inside-delta wiring and control voltage
This soft starter supports inside-delta circuit configuration, which means the thyristors sit inside the motor delta winding rather than in the supply lines. That cuts the phase current the thyristors see by about 58%, effectively letting a 133 A unit control a motor with a higher FLA than its line rating would suggest — a common trick for larger motors where a smaller soft starter saves panel space and cost. The auxiliary and control circuit uses spring-loaded terminals; the main current circuit uses box terminals sized for 2x (4 … 50 mm²) stranded.
Mounting, clearances, and environmental limits
Mounting is screw-fixing on a vertical surface, rotatable ±90° and tiltable ±22.5° front-to-back. Keep 100 mm clearance above and 75 mm below for airflow. The 270 mm depth fits a standard enclosure with room for wiring.