Panel fit and mounting constraints
The 3RW4425-3BC34 measures 170 mm wide by 192 mm high by 270 mm deep and mounts via screw fixing, not DIN rail — plan for four drilled holes on the backplate. Mounting position allows vertical surface with ±90° rotation and ±22.5° tilt front-to-back, giving flexibility in tight enclosures. Clearance requirements: 100 mm above, 75 mm below, 5 mm at the sides — the top gap is critical for heat plume rise from the thyristor stack.
Current ratings and thermal derating
Minimum load is 8 % of the rated current — below that the soft starter may not trigger the thyristors reliably; check the motor magnetising current against this floor.
Wiring and termination details
Auxiliary and control circuit wiring uses spring-loaded terminals for 2x (24... 16 AWG) — no screw tightening, just push in for solid or ferruled stranded. Maximum motor cable length is 500 m — beyond that, reflected wave voltages on the motor terminals can stress the winding insulation, especially on 690 V systems.
Protection and control features
Integrated bypass contact system means the thyristors are shorted out after start — no continuous heat dissipation in the power stack during run, so the enclosure thermal load drops significantly. Adjustable current limitation lets you set the start current between the motor's no-load and locked-rotor values — useful for soft-starting conveyors or pumps without tripping upstream protection. Motor overload protection and intrinsic device protection are both built in — the soft starter monitors its own heatsink temperature and the motor thermal model, so an external overload relay is optional. Inside-delta wiring is supported — connect the soft starter in the delta loop of a six-lead motor to reduce the current rating needed per phase by about 58 %.
Environmental and compliance data
Pollution degree 3 per IEC 60947-4-2 — suitable for industrial environments with conductive dust or occasional condensation; the enclosure should maintain at least IP54 around the unit.