355 kW Soft Starter 3RW4444-6BC44 | Advanced Soft Starter 400 V

Product Description / Overview

The Siemens 3RW4444-6BC44 is a refurbished SIRIUS soft starter designed for demanding three-phase motor applications.
It delivers controlled acceleration and deceleration, therefore reducing mechanical stress and electrical peak currents effectively.

Moreover, this unit belongs to the advanced SIRIUS 3RW44 series, combining soft starting with integrated bypass technology.
It supports high-power motors while maintaining reliable operation in continuous industrial environments.

In addition, refurbished units are professionally tested to ensure electrical performance meets original Siemens specifications.
Therefore, this model remains a dependable choice for maintaining legacy installations or replacing discontinued equipment.

Technical Data / Specifications

Product Type: Soft Starter
Series: SIRIUS 3RW44
Manufacturer: Siemens AG

Rated Operational Voltage (Ue): 200–460 V AC, three-phase
Rated Motor Power: Up to 355 kW at 400 V (AC-53b duty)
Rated Operational Current (Ie): 700 A

Control Supply Voltage (Us): 110–250 V AC/DC
Starting Method: Voltage ramp with adjustable start and stop parameters
Integrated Bypass: Yes

Protection Functions:

• Motor overload protection

• Thermistor motor protection evaluation

• Intrinsic device protection

Special Functions:

• Current limitation

• Inside-delta connection support

• Motor brake output

• External reset input

Insulation Voltage (Ui): 690 V
Utilization Category: AC-53b according to IEC 60947-4-2
Pollution Degree: 3

Operating Temperature: –25 °C to +60 °C
Storage Temperature: –40 °C to +80 °C

Mounting Type: Panel mounting
Protection Class: IP20 (installation in enclosure required)

Dimensions (H × W × D):  470 × 320 × 250 mm
Weight: 3.2 kg

Product Status: Phased-out product
Recommended Successor: SIRIUS 3RW5 series

FAQ

Is the Siemens 3RW4444-6BC44 still supported by Siemens?
This model is discontinued, however documentation and accessories remain available for existing installations.

What is the recommended replacement for new projects?
Siemens recommends the SIRIUS 3RW5 series as the successor platform.

Does this soft starter include an internal bypass?
Yes, an integrated bypass contactor reduces heat losses during normal motor operation.

Can it be used with thermistor-protected motors?
Yes, it supports direct thermistor motor protection evaluation.

Is this unit suitable for inside-delta motor connections?
Yes, inside-delta operation is supported to optimize current and power handling.