Panel fit and mounting — Size S0 frame
The 3RW3027-2BB14 is a Size S0 frame soft starter, 45 mm wide, 150 mm deep, and 150 mm tall. Mounting position allows ±10° rotation and ±10° tilt forward/back from vertical. Clearance requirements: 60 mm upward, 40 mm downward, 15 mm at the sides for airflow.
Current ratings and thermal derating
The derating starts at 40 °C — above that, the continuous current drops linearly. For a 25 A motor at 50 °C ambient, this unit has 4 A headroom. Minimum load is 10% of the rated current — below that the thyristor firing angle may not hold conduction. For a 32 A unit, the motor should draw at least 3.2 A at start.
Termination and wiring — spring-loaded terminals
Auxiliary and control circuits also use spring-loaded terminals, wire range 2x (24... 14 AWG). Front clamping point accepts 1x 8 AWG or 2x (16... 10 AWG) for larger conductors. Maximum motor cable length is 300 m — beyond that, capacitive charging current may cause nuisance tripping.
Control supply and bypass — what's built in
Control supply voltage is 110... 230 V DC — a single DC rail covers both 110 V and 230 V control systems without rewiring. Operating frequency is 50... 60 Hz. Integrated bypass contact system means the thyristors are shorted out after the motor reaches full speed — no external bypass contactor needed, and the heat load drops to near zero during run. No motor overload protection built in — an external overload relay (e.g., Siemens 3RU2 series) is required. No adjustable current limitation, no inside-delta circuit, no motor brake output.
Lifecycle and sourcing — current production
Lifecycle stage is current production — this is an active catalog item from Siemens, not a phase-out or NRND part. Storage temperature range -40... +80 °C per IEC 60721 class 1K6 (occasional condensation, no salt mist, sand excluded). Operating temperature -25... +60 °C.