Product Overview
With a rated operational current of 780 A at 400 V, the Siemens 3RW4456-6BC44 SIRIUS soft starter is designed for demanding motor control applications. This industrial automation module delivers 450 kW in standard circuit and up to 800 kW in inside-delta configuration. The product has been phased out, with the preferred successor being the Siemens 3RW5554-6HA14.
Technical Specifications
| Parameter |
Value |
| Rated operational current (40 °C, standard circuit) |
780 A |
| Rated operational current (40 °C, inside-delta) |
1351 A |
| For 400 V, standard circuit, yielded mechanical power |
450 kW |
| For 400 V, inside-delta circuit, yielded mechanical power |
800 kW |
| Operating voltage range (standard & inside-delta) |
200 ... 460 V AC |
| Control supply voltage |
230 V AC at 50/60 Hz |
| Power loss at 40 °C, typical |
214 W |
| Enclosure protection class (front) |
IP00 |
| Dimensions (W x H x D) |
510 x 640 x 290 mm |
| Main circuit connection |
Busbar connection |
| Auxiliary/control circuit connection |
Screw-type terminals |
Industry Applications
The Siemens 3RW4456-6BC44 soft starter is ideal for controlling large AC motors in pump, fan, compressor, and conveyor systems. Its high current ratings (780 A standard, 1351 A inside-delta) make it suitable for heavy industrial environments. The inside-delta circuit capability reduces line current by approximately 58%, allowing it to start larger motors without overloading the supply.
Installation & Setup
Mount the Siemens 3RW4456-6BC44 using screw fixing on a vertical surface with +/-90° rotatability and +/-22.5° tilt. Maintain minimum clearances: 100 mm upward, 5 mm sides, 75 mm downward. Use busbar connections for the main circuit (cable lug cross-sections: finely stranded 50-240 mm², stranded 70-240 mm²) and screw terminals for auxiliary circuits. Maximum wire length is 500 m.
Maintenance & Reliability
The Siemens 3RW4456-6BC44 includes an integrated bypass contact system and thyristors, plus features such as intrinsic device protection, motor overload protection, and thermistor motor protection evaluation. Operating temperature range is up to 60 °C (ambient) with derating at 40 °C. The device is designed for industrial environments meeting IEC 60721 categories for transport, storage, and operation.
Selection Guide & Purchasing Advice
Since the Siemens 3RW4456-6BC44 is a phased-out product, consider ordering the successor Siemens SIRIUS 3RW5554-6HA14 for new installations. If you require this exact model for legacy system maintenance, verify stock availability. For reliable sourcing of automation spares, including Siemens 3RW4456-6BC44, consult PLC Source PRO (available through ubest101) to ensure genuine components and professional support.