Current ratings and thermal derating
The 3RW4076-2BB45 is rated 432 A at 40 °C, 385 A at 50 °C, and 335 A at 60 °C — the derating above 40 °C is steep, so the ambient inside the panel determines the usable current. The derating temperature is 40 °C; above that, the thyristor junction temperature limits the continuous output. For a 50 °C panel ambient, budget 385 A maximum.
Mounting and panel integration
Fastening is screw fixing, not DIN rail — the Size S12 frame (160 mm wide, 230 mm high, 278 mm deep) bolts directly to the backplate. Clearance above the unit is 100 mm, below 75 mm, and at the side 5 mm. Mounting position is constrained: with an additional fan, the unit can be mounted vertically with +/-90° rotation and +/-22.5° tilt front/back. Without the fan, only +/-10° rotation and +/-10° tilt is allowed — plan the orientation before drilling the gland plate.
Wiring and connection
Main circuit connections accept stranded cable 70...240 mm² or busbar connections; the front clamping point takes 3/0...600 kcmil, the back clamping point 250...500 kcmil. Using both clamping points requires min. 2x 2/0, max. 2x 500 kcmil. Auxiliary contacts accept 2x (24...16) AWG solid wire (0.25...1.5 mm²). The maximum motor cable length is 300 m — beyond that, reflected wave voltage can stress the thyristors.
Environmental and protection
Operating ambient is -25...+60 °C; storage range is -40...+80 °C. Insulation voltage rated at 600 V, operating frequency 50...60 Hz at 230 V. Intrinsic device protection and motor overload protection are integrated — the soft starter monitors the motor current directly.