Motor starting with integrated bypass
The 3RW4425-3BC35: It includes an integrated bypass contact system, so once the motor reaches full speed, the thyristors are shorted and heat dissipation drops to near zero — no external bypass contactor needed. Current derating is linear: 88 A at 50 °C and 78 A at 60 °C, with derating starting above 40 °C. The minimum load is 8% of the rated current, which matters for lightly loaded motors or pumps that start near empty.
Panel fit and wiring
The unit measures 192 mm high by 170 mm wide by 270 mm deep, mounts via screw fixing, and allows vertical mounting with ±90° rotation and ±22.5° tilt front-to-back — useful when retrofitting into an existing enclosure where the backplate is already drilled. Main circuit connections use box terminals accepting 2x (4 to 50 mm²) stranded or 2x (10 to 1/0 AWG) with both clamping points. Maximum motor cable length is 500 m — sufficient for most distributed motor installations without a output reactor, though long runs in high-capacitance cable may still need one depending on the installation.
Protection and control features
Built-in motor overload protection and intrinsic device protection are standard. The adjustable current limitation lets you set the starting current between the minimum load of 8% and the rated current, reducing mechanical shock on the driven load. The soft starter supports inside-delta circuit wiring, which reduces the current through the thyristors by a factor of √3 compared to standard in-line connection — useful for larger motors where the soft starter frame size can be reduced. An external reset input and a display for fault signals are provided, so the starter can be reset from a remote panel without opening the enclosure door.
Environmental and compliance
Operating temperature range is up to 60 °C; storage range is -25 to +80 °C.