Sizing for the load — current derating and ambient heat
The 3RW4434-6BC45 is a SIRIUS soft starter rated 196 A at 40 °C. At 50 °C that drops to 173 A, and at 60 °C it's 152 A. It handles an insulation voltage of 690 V and operates at 50 to 60 Hz. Pollution degree 3 per IEC 60947-4-2 means it's rated for industrial environments where conductive dust or occasional condensation is present — no derating for that.
Inside-delta wiring and current limitation
This unit supports inside-delta circuit connection, which reduces the current through the soft starter to 58% of the motor FLA compared to standard in-line wiring. That's the configuration that lets you run a higher motor current through a given soft starter frame. Adjustable current limitation is built in — set the start current ceiling as a percentage of the soft starter rating. The minimum load threshold is 8% of the rated current, so it can handle lightly loaded motors without nuisance tripping.
Mounting and panel fit
Fastening is by screw fixing. The mounting position allows a vertical surface with ±90° rotation and ±22.5° tilt front-to-back — you can orient it to fit the cabinet layout without derating. Dimensions are 170 mm wide, 200 mm high, 270 mm deep. Clearance: 100 mm above, 75 mm below, 5 mm at the sides. Conductor sizes range from 25 to 120 mm² stranded for the main circuit, with auxiliary contacts accepting 20-14 AWG.