Siemens 3RW4445-6BC44 Soft Starter 313A 160kW

3RW4445-6BC44 SIRIUS Soft Starter for High-Feature Applications

The 3RW4445-6BC44 belongs to Siemens’ SIRIUS product family. You can use it for demanding motor starting applications. This device reduces inrush current and mechanical stress. It also provides reliable motor overload protection.

Key Technical Parameters of the 3RW4445-6BC44

This soft starter operates at a rated voltage of 200–460V AC. For standard circuits, the operating current reaches 313A at 40°C. In inside-delta configuration, it goes up to 542A at 40°C.

The mechanical power output is 160kW at 400V under standard switching. For inside-delta circuits, it delivers 315kW at the same voltage. Additionally, the device supports a frequency range of 50–60 Hz with ±10% tolerance. The adjustable motor current ranges from 62A up to the rated value.

Control Supply and Protection Features

The 3RW4445-6BC44 requires a 230V AC control supply at 50 or 60 Hz. It includes an integrated bridging contact system and thyristors. Moreover, the unit offers intrinsic device protection and motor overload protection. It also evaluates thermal resistor inputs for motor protection.

Furthermore, you can perform an external reset. The device has an adjustable current limitation and supports inside-delta wiring. It even includes an outlet for an engine brake.

Mechanical Dimensions and Mounting Instructions

The 3RW4445-6BC44 measures 210 mm in width, 230 mm in height, and 298 mm in depth. Its protection class is IP00, suitable for installation inside control cabinets. You can mount it using screw fixing.

When installing, keep the following clearances: 100 mm upward, 5 mm sideways, and 75 mm downward. The device allows a maximum cable length of 500 meters. It supports installation altitudes up to 5,000 meters above sea level.

The operating temperature ranges from -25°C to 60°C. However, note that derating starts at 40°C. For example, at 50°C, the standard operating current reduces to 280A. At 60°C, it further reduces to 250A.

Electrical Connections and Terminal Details

Main current circuit connections use busbar terminals. They accept stranded conductors from 95 mm² to 300 mm². Finely stranded wires with end processing work from 70 mm² to 240 mm². For AWG conductors, the range is 2/0 to 500 kcmil.

Auxiliary and control circuits use screw-type terminals. This model provides three normally open (NO) auxiliary contacts and one changeover contact. It does not include any normally closed (NC) contacts. Each auxiliary connection accepts solid wires of 0.5 to 2.5 mm².

Frequently Asked Questions (FAQ)

1. What is the difference between standard and inside-delta connection for the 3RW4445-6BC44?
Standard connection uses 313A and delivers 160kW at 400V. Inside-delta connection uses 542A and delivers 315kW. The latter reduces motor current by 1/√3, allowing higher power output.

2. Can I use the 3RW4445-6BC44 at 60°C ambient temperature?
Yes, but you need to derate the current. At 60°C, the standard operating current drops to 250A. For inside-delta operation, it drops to 433A.

3. What type of motor protection does this soft starter include?
The 3RW4445-6BC44 provides motor overload protection and thermal resistor evaluation. It also features adjustable current limitation and intrinsic device protection.

4. What is the maximum cable length for this device?
You can use cables up to 500 meters between the soft starter and the motor. Longer cables may require additional output filters.

5. How do I reset the device after a fault?
You can perform an external reset via the control terminals. Alternatively, you can use the display for fault signal diagnosis before resetting.