Continuous current and the derating that matters
The 3RW4444-2BC46: That 40 °C figure is the baseline — in a closed panel with other heat sources, expect to budget for the 50 °C or 60 °C column unless you have forced ventilation. Insulation voltage rated 690 V, operating frequency 50…60 Hz. The 690 V ceiling means this unit handles 400 V line-to-line systems with margin; no voltage derating needed for standard 380–480 V grids.
Inside-delta wiring and current limitation
Supports inside-delta circuit configuration — the soft starter connects in the delta legs of a six-lead motor, reducing the line current the device carries relative to the motor full-load current. For a given motor, this lets a smaller-frame soft starter do the job. Adjustable current limitation lets you set the start current between 8% and 100% of the device rating. The 8% minimum load threshold means the thyristors may not fire reliably below that point — factor this into no-load commissioning or very light loads.
Panel layout and wiring constraints
Clearance requirements: 100 mm above, 75 mm below, 5 mm at the sides — these are for ventilation and arc-flash separation per IEC 60947-4-2. Main circuit accepts stranded 70…240 mm² or kcmil 2/0…500. Auxiliary connections take solid 0.25…1.5 mm². The main current circuit uses busbar connection — plan for busbar lugs, not cable lugs, on the power terminals. Dimensions 230 mm high, 210 mm wide, 298 mm deep. The depth is the largest envelope — ensure the enclosure depth accommodates the unit plus the 100 mm top clearance for cable bending and airflow.
Protection and diagnostics built in
Integrated motor overload protection eliminates the separate overload relay in many panels. Intrinsic device protection covers the soft starter itself against overtemperature and overcurrent. On-board display for fault signals — no external HMI needed for basic diagnostics. External reset input allows remote clearing of fault conditions. Pollution degree 3 per IEC 60947-4-2 — rated for industrial environments with conductive dust or occasional condensation. Storage temperature -25…+80 °C, operation up to 60 °C ambient.