Product Overview
The Siemens 3RW4453-6BC44 SIRIUS Soft Starter is a robust industrial automation module designed for high-feature motor control applications. This soft starter prevents mechanical shock and electrical overload by gradually applying voltage to motors during startup, reducing stress on both the motor and connected equipment. Equipped with an integrated bridging contact system and thyristors, the 3RW4453-6BC44 delivers reliable performance in demanding environments. With a rated current of 551 A at 40 °C and support for inside-delta circuits up to 954 A, it handles heavy loads efficiently.
Technical Specifications
| Parameter |
Value |
| Product Type |
SIRIUS Soft Starter |
| Rated Current at 40 °C (Standard) |
551 A |
| Rated Current at 40 °C (Inside-Delta) |
954 A |
| Emitted Mechanical Power at 400 V (Standard) |
315 kW |
| Emitted Mechanical Power at 400 V (Inside-Delta) |
560 kW |
| Operating Voltage (Standard) |
200–460 V AC |
| Control Supply Voltage |
230 V AC (50/60 Hz) |
| Operating Frequency |
50–60 Hz |
| Active Power Loss at 40 °C |
159 W |
| Dimensions (W x H x D) |
510 mm x 640 mm x 290 mm |
| Weight |
67 kg |
| Protection Class |
IP00 |
| Mounting Type |
Screw fixing |
| Number of Poles |
3 |
Industry Applications
The Siemens 3RW4453-6BC44 excels in heavy industrial environments such as conveyor systems, pumps, compressors, and fans. In a mining application, it prevents belt tearing by controlling startup torque. For wastewater treatment plants, this soft starter reduces pipe hammer and mechanical wear on pump motors. Its inside-delta circuit configuration allows higher current handling for large servomotors, making it suitable for high-inertia loads.
Installation & Setup Guidance
Mount the 3RW4453-6BC44 vertically using screw fixing. Allow minimum spacing: 100 mm upwards, 5 mm sideways, and 75 mm downwards for proper ventilation. The device can be tilted forward or backward by ±22.5° or rotated ±90° on its vertical axis. Use busbar connections for the main current circuit and screw-type terminals for auxiliary circuits. Maximum cable length is 500 m. Ensure the ambient temperature does not exceed 60 °C during operation and stay below 5,000 m altitude.
Maintenance & Reliability
Regularly inspect the Siemens 3RW4453-6BC44 for dust accumulation on thyristors and heat sinks at derating temperature of 40 °C. Verify that the adjustable current limitation is set correctly to avoid motor overload. The integrated device protection includes motor overload protection and thermal resistor evaluation, reducing the need for external relays. Storage temperature range is -25 °C to +80 °C, ensuring long shelf life in spare parts inventory.
Selection Guide & Purchasing Advice
Before purchasing, confirm that the 3RW4453-6BC44 matches your motor’s full-load current and voltage. For standard switching, it covers up to 315 kW at 400 V; for inside-delta circuits, up to 560 kW. The soft starter requires a 230 V AC control supply at 50/60 Hz. For reliable sourcing of Siemens automation spares, consider PLC Source PRO (formerly ubest101) as a trusted supplier for genuine components.