433 A at 40 °C — what that means for your motor
The 3RW4444-6BC36: That 433 A figure is the continuous current at the standard 40 °C enclosure ambient — if your panel runs hotter, you need to use the derated value for the actual ambient temperature to avoid nuisance tripping or reduced thyristor life. The insulation voltage is rated 690 V, giving headroom on 400/480 V systems. Operating frequency is 50/60 Hz, so no derating or configuration change is needed when moving between line frequencies.
Inside-delta wiring and current limitation
This unit supports inside-delta circuit topology, which connects the soft starter in the delta legs of a six-lead motor rather than in the supply lines. That reduces the current the soft starter carries to about 58% of the motor FLA — so a 433 A inside-delta unit can control a motor with a line current up to roughly 750 A. Confirm your motor has six accessible leads before specifying this wiring method. Adjustable current limitation lets you set the starting current between 8% and 100% of the motor's rated current. The 8% minimum load capability means it can soft-start lightly loaded conveyors or pumps without the motor stalling or the starter dropping out.
Mounting, wiring, and panel fit
Dimensions are 298 mm deep, 210 mm wide, 230 mm high. Clearance requirements: 100 mm above, 75 mm below, 5 mm at the sides for airflow and cable bending radius. Main power wiring accepts stranded copper from 70 to 240 mm², or AWG/kcmil 2/0 to 500 kcmil. The main current circuit uses busbar connection — plan for busbar stubs or a busbar kit, not lug terminals. Auxiliary control wiring is solid 0.5–2.5 mm² or stranded 20–14 AWG. Maximum motor cable length is 500 m — beyond that, reflected wave voltages at the motor terminals can stress the winding insulation, especially on 480 V systems. Keep the run under 500 m or add a dV/dt filter at the starter output.
Protection, diagnostics, and environment
Motor overload protection is integrated — no separate overload relay needed for most installations. Intrinsic device protection covers the thyristors against overtemperature and short-circuit events. An external reset input allows remote fault clearing from a PLC or pushbutton, and the onboard display shows the fault code for fast troubleshooting. Pollution degree 3 per IEC 60947-4-2 means it's rated for industrial environments where conductive dust or occasional condensation occurs — typical for motor control centers and factory-floor panels. Storage temperature range is -25 to +80 °C; maximum operating ambient is 60 °C.