Panel fit and derating reality
The 3RW4424-3BC36 occupies 192 mm height by 170 mm width by 270 mm depth, screw-fixed to the backplate — not DIN-rail snap-on, so budget four corner fasteners and a drill template.
Wiring and termination
Main power circuit uses box terminals accepting 2x (4... 50 mm²) stranded — that covers most motor cables up to 95 A class. Maximum motor cable length is 500 m — beyond that, capacitive charging current from the cable can interfere with the soft starter's firing circuit; keep runs under that for reliable starting.
Motor protection and control features
Built-in motor overload protection and intrinsic device protection mean no separate overload relay is needed for most applications — the soft starter handles thermal memory and fault lockout internally. Adjustable current limitation lets you cap starting current below the supply transformer or generator rating — set it as a percentage of the motor FLA, and the thyristors clip the current envelope. Minimum load is 8 % of the rated current — below that, the motor may not generate enough back-EMF for the soft starter to detect the end of start; light-load applications need a check against this threshold.
Inside-delta and bypass — what they mean for the cabinet
Inside-delta wiring (six-wire connection) reduces the current through each thyristor to 58 % of the line current — useful when the motor is far from the panel and cable sizing is tight, or when the soft starter's rating is marginal for the motor FLA. Integrated bypass contact system closes after the start ramp, taking the thyristors out of the circuit for steady-state running — this eliminates thyristor conduction losses and keeps the enclosure cooler during continuous duty.