230 A continuous — the thermal ceiling that governs the motor
The 3RW4073-2BB34: That 230 A is the continuous current the thyristor stack can carry without exceeding the junction temperature limit — it sets the maximum motor FLA this unit can start and run across. Built-in motor overload protection and intrinsic device protection mean the soft starter handles both the motor thermal model and its own heatsink monitoring — no separate overload relay needed in most installations. The adjustable current limitation lets you cap the start current below the full-voltage locked-rotor draw, which is the whole point of a soft starter on a conveyor or pump. Frame size S12 tells the panel builder the busbar pattern and the mounting hole layout. The unit is screw-fixed to a vertical surface; without the add-on fan the tilt tolerance is tight (±10°), so the panel backplate needs to be reasonably plumb. With the fan you get ±90° rotation and ±22.5° tilt front-to-back.
Wiring and integration — main circuit is busbar, control is screw-clamp
The main circuit connection is via busbar — no cable lugs on the thyristor poles. The busbar cross-section range is 70–240 mm² stranded or 50–240 mm² finely stranded, with an alternative kcmil range of 2/0–500 kcmil for the main contacts. The back clamping point accepts 250–500 kcmil; the front point takes 3/0–600 kcmil. If you're using both clamping points, the minimum is 2x 2/0 and the maximum is 2x 500 kcmil. The maximum motor cable length is 300 m, which covers most in-plant runs but may be marginal for long-distance well-pump installations. Pollution degree 3 per IEC 60947-4-2 means the creepage distances are designed for conductive pollution environments — typical in industrial panels where dust and humidity combine. The 600 V insulation voltage rating covers 480 V and 600 V nominal systems with margin.
Active production — standard BOM line, not a legacy hunt
The SIRIUS family is Siemens' mainstream soft starter platform, so spare parts, documentation, and SITOP power supply compatibility are all current. The unit is not an inside-delta configuration — it's a standard in-line soft starter, which is the common topology for most pump and fan applications.