The Siemens 3RW4434-6BC44 is a SIRIUS soft starter rated 196 A at 40 °C and 230 V at 50/60 Hz. It uses thyristors to ramp motor voltage during start, reducing inrush and mechanical shock. The inside-delta circuit configuration is supported, which lets you use a smaller starter for a given motor by connecting the thyristors in the delta legs.
The 196 A rating at 40 °C is your starting point for motor sizing — it drops to 173 A at 50 °C and 152 A at 60 °C, so if your panel runs hot, you need to derate accordingly. The minimum load is 8% of the rated current — below that, the thyristors may not fire cleanly, so don't use this on a no-load test bench without a ballast.
Mounting is screw fixing on a vertical surface, rotatable ±90° and tiltable ±22.5° front/back. That gives flexibility in panel layout, but the clearance rules are specific: 100 mm above, 75 mm below, 5 mm at the sides. The main circuit connects via busbar or cable — stranded 25–120 mm² or finely stranded 16–95 mm², plus 4–250 kcmil for larger builds. Maximum motor cable length is 500 m — beyond that, capacitive charging current can interfere with the thyristor firing.