Siemens 3RW4074-6BB44 Soft Starter for Pumps and Conveyors

Product Description

Product Overview

The Siemens 3RW4074-6BB44 is a SIRIUS soft starter designed for reliable starting of three-phase asynchronous motors.
It enables controlled motor acceleration and deceleration, therefore reducing mechanical stress and electrical peak currents.
Moreover, this soft starter integrates seamlessly into modern motor control systems using Siemens SIRIUS components.
It belongs to the 3RW40 series, which engineers widely select for standard industrial motor starting applications.

Technical Specifications

• Manufacturer: Siemens AG

• Product Series: SIRIUS 3RW40

• Model: 3RW4074-6BB44

• Product Type: Soft starter for standard applications

• Control Device Size: S12

• Rated Operating Voltage: 200–460 V AC, three-phase

• Rated Frequency: 50–60 Hz

• Control Supply Voltage Type: AC

• Motor Power Rating:

• 75 hp at 200/208 V AC, 50 °C standard circuit

• Up to 160 kW at higher supply voltages

• Starting Method: Voltage ramp soft start and soft stop

• Integrated Bypass: Yes

• Utilization Category: AC-53b (IEC 60947-4-2)

• Protection Functions: Motor overload monitoring, phase failure detection

• Mounting Method: Panel mounting

• Operating Temperature Range: –25 °C to +60 °C

• Storage Temperature Range: –40 °C to +80 °C

• Protection Class: IP20 (open type, enclosure required)

• Dimensions (L × W × H): 278 × 160 × 230 mm

• Shipping Weight: 10 kg

• Standards Compliance: IEC, UL, CSA

FAQ

Q1: What motor size is supported by the Siemens 3RW4074-6BB44?
It supports motors up to 75 hp at 200/208 V and up to 160 kW at higher voltages.

Q2: Does this soft starter include an internal bypass contactor?
Yes, the integrated bypass reduces heat losses during normal motor operation.

Q3: Can the starting and stopping behavior be adjusted?
Yes, ramp-up time, ramp-down time, and starting voltage are fully adjustable.

Q4: Is this soft starter suitable for continuous industrial operation?
Yes, it is designed for standard industrial environments and continuous duty applications.

Q5: Does it require an external motor protection relay?
Additional protection may be required depending on local standards and system design.