Motor starting duty and current ratings
The 3RW4075-6BB34: The 20% minimum load threshold means this unit won't regulate properly below that current level — don't oversize it for a motor that runs well under 20% of the soft starter's rating. Integrated motor overload protection and adjustable current limitation let it serve as both starter and protector in one device, saving a panel row and the wiring between a separate overload relay.
Panel integration and mounting constraints
Size S12 frame measures 230 mm high, 160 mm wide, 278 mm deep — the depth is the dimension to watch when laying out a deep cabinet against a back panel or gland plate. Screw fixing to the mounting surface; the mounting position is restricted to vertical surface with ±10° rotation and ±10° tilt without an additional fan, or ±90° rotation and ±22.5° tilt with one. Clearance requirements: 100 mm above, 75 mm below, 5 mm at the sides — the top clearance is the binding constraint for airflow and cable bend radius.
Wiring terminations and conductor sizes
Main current circuit uses busbar connection with a front clamping point accepting 3/0 to 600 kcmil and a back clamping point for 250 to 500 kcmil — the busbar approach handles the 356 A continuous current without the voltage drop of a lugged cable. Stranded main power cables: 70 to 240 mm²; finely stranded: 50 to 240 mm²; AWG/kcmil equivalents: 2/0 to 500 kcmil using both clamping points.
Environmental and compliance profile
Insulation voltage rated 600 V, operating frequency 50/60 Hz — the 600 V rating covers 480 V and 575 V systems with margin.
Sourcing and lifecycle status
The SIRIUS product brand means full Siemens documentation and support apply.