The Siemens SIRIUS 3RW4036-1BB05 is a size S2 soft starter rated for 45 A at 40 °C, 42 A at 50 °C, and 39 A at 60 °C, operating on 50/60 Hz supplies at 24 V control voltage. It includes an integrated bypass contact system and thyristors for smooth motor acceleration. The adjustable current limitation lets you dial in the starting current to match the load, and the minimum load of 20 % means it handles light loads without dropping out.
Mounting & Terminals
Fastens with screw and snap-on mounting to a DIN rail. The main current circuit uses screw-type terminals; the auxiliary contacts accept solid wire 2x (0.5 to 2.5 mm²) and stranded 2x (1.5 to 25 mm²). The back clamping point takes 16 to 2 AWG, front clamping point 18 to 2 AWG. Overall width is 55 mm, height 160 mm, depth 170 mm. Clearance: 60 mm upwards, 40 mm downwards, 30 mm at the side. Mounting position: with an additional fan, the unit can be rotated ±90° on a vertical surface or tilted ±22.5° front/back; without a fan, rotation and tilt are limited to ±10°. That's tight — if you're packing a panel without forced airflow, plan for that 10° envelope.
Protection & Environment
Rated insulation voltage 600 V. Derating starts at 40 °C — at 60 °C the current rating drops to 39 A. Motor overload protection is onboard, and intrinsic device protection is included. The fault signal is a red LED display. External reset is supported. Maximum motor wire length is 300 m. Not designed for inside-delta circuit configuration.