Product Overview

The Siemens 3RW4076-6BB44 is a SIRIUS S12 soft starter. This device includes an integrated bypass contact system and thyristors for smooth motor starting.

The soft starter provides intrinsic device protection and motor overload protection. Additionally, it features adjustable current limitation and external reset capability. The 3RW4076-6BB44 operates at 200-460V AC with a 230V AC control supply. Important Note: This is a phased-out product. The preferred successor type is 3RW5076-6AB14 from the SIRIUS 3RW5 series.

General Specifications

The 3RW4076-6BB44 offers robust performance for motor control applications.

• Manufacturer: Siemens.

• Product Brand Name: SIRIUS.

• Product Designation: Soft starter S12.

• Integrated Bypass Contact System: Yes.

• Thyristors: Yes.

• Motor Overload Protection: Yes.

• Adjustable Current Limitation: Yes.

• External Reset: Yes.

• Inside-Delta Circuit: No.

• Motor Brake Output: No.

• Insulation Voltage (Rated): 600 V.

• Degree of Pollution: 3 (acc. to IEC 60947-4-2).

Power Electronics Specifications

The 3RW4076-6BB44 delivers high current and power ratings.

Operational Current:

• At 40°C (Rated): 432 A.

• At 50°C (Rated): 385 A.

• At 60°C (Rated): 335 A.

Yielded Mechanical Power (3-phase motors at 40°C):

• At 230 V (standard circuit): 132 kW.

• At 400 V (standard circuit): 250 kW.

• At 200/208 V (50°C, HP): 125 hp.

Operating Voltage (Standard Circuit):

• Rated Value: 200 to 460 V AC.

• Negative Tolerance: -15%.

• Positive Tolerance: +10%.

Operating Frequency:

• Rated Value: 50 to 60 Hz.

• Negative Tolerance: -10%.

• Positive Tolerance: +10%.

Additional Parameters:

• Minimum Load: 20%.

• Adjustable Motor Current (min): 207 A.

• Continuous Operating Current (% of Ie at 40°C): 115%.

• Power Loss (typical at 40°C): 165 W.

Control Circuit Specifications

The 3RW4076-6BB44 uses AC control supply voltage.

• Control Supply Voltage Type: AC.

• Control Supply Voltage (50/60 Hz): 230 V AC.

• Frequency Tolerance: -10% to +10%.

• Voltage Tolerance: -15% to +10%.

Display:

• Fault Signal: Red.

Mechanical Specifications

The 3RW4076-6BB44 has a robust mechanical design.

• Size: S12.

• Width: 160 mm.

• Height: 230 mm.

• Depth: 278 mm.

• Fastening Method: Screw fixing.

• Maximum Wire Length: 300 m.

• Number of Poles (Main Current Circuit): 3.

Mounting Position:

• With Additional Fan: Vertical mounting surface +/-90° rotatable, +/-22.5° tiltable.

• Without Additional Fan: Vertical mounting surface +/-10° rotatable, +/-10° tiltable.

Required Spacing:

• Upwards: 100 mm.

• Side: 5 mm.

• Downwards: 75 mm.

Terminal and Connection Specifications

The 3RW4076-6BB44 uses busbar connections for main current and screw terminals for control circuits.

Auxiliary Contacts:

• Number of NC Contacts: 0.

• Number of NO Contacts: 2.

• Number of CO Contacts: 1.

Main Contact Conductor Cross-Sections (Front Clamping Point):

• Finely Stranded (with/without core end processing): 70-240 mm².

• Stranded: 95-300 mm².

Main Contact Conductor Cross-Sections (Back Clamping Point):

• Finely Stranded (with/without core end processing): 120-185 mm².

• Stranded: 120-240 mm².

AWG Cables (Main Contacts):

• Back Clamping Point: 250-500 kcmil.

• Front Clamping Point: 3/0-600 kcmil.

Auxiliary Contacts:

• Solid: 2x (0.5-2.5 mm²).

• Finely Stranded (with core end processing): 2x (0.5-1.5 mm²).

Ambient Conditions

The 3RW4076-6BB44 operates in a range of environmental conditions.

• Installation Altitude (max): 5,000 m above sea level.

• Derating Temperature: 40°C.

• Ambient Temperature (operation): -25 to +60°C.

• Ambient Temperature (storage): -40 to +80°C.

• Protection Class: IP00.

Environmental Categories (acc. to IEC 60721):

• Transport: 2K2, 2C1, 2S1, 2M2 (max fall height 0.3 m).

• Storage: 1K6, 1C2, 1S2, 1M4.

• Operation: 3K6, 3C3, 3S2, 3M6.

Successor Information

The 3RW4076-6BB44 is a phased-out product. Siemens recommends the SIRIUS 3RW5 series as the successor. The preferred successor type is 3RW5076-6AB14.

Therefore, consider the 3RW5 series for new designs. Legacy systems may still use the 3RW4076-6BB44 for replacement purposes.

Key Features

The 3RW4076-6BB44 offers several advantages for motor starting applications.

Integrated Bypass Contact System:
Reduces power loss during continuous operation. Consequently, heat dissipation is minimized.

Adjustable Current Limitation:
Limits starting current to protect the motor and supply network. Hence, it reduces voltage dips during motor start.

Motor Overload Protection:
Provides thermal protection without external overload relays. Therefore, it simplifies the control cabinet.

External Reset Capability:
Allows remote reset after a fault condition. Thus, it improves operational convenience.

Wide Voltage Range:
Operates from 200 to 460 V AC. For this reason, it suits global applications with different supply voltages.

High Ambient Temperature Rating:
Delivers 432A at 40°C and 335A at 60°C. Consequently, it performs reliably in warm environments.

Typical Applications

The 3RW4076-6BB44 suits various motor starting applications.

• Centrifugal pumps and fans.

• Compressors and conveyors.

• Mills and crushers.

• Mixers and agitators.

• Any application requiring reduced voltage starting.

Installation Guidelines

Install the 3RW4076-6BB44 in a vertical mounting orientation. Ensure proper spacing (100 mm up, 75 mm down, 5 mm sides) for cooling. Use screw fixing for secure mounting.

Connect main current cables using busbar connections. Use cable lugs or box terminals per the specified cross-sections. For AWG cables, use 3/0 to 600 kcmil at the front clamping point.

Connect control voltage (230V AC, 50/60 Hz) to the screw terminals. Wire the auxiliary contacts (2 NO, 1 CO) as required. Set the motor current between 207A and 432A using the adjustment dial.

What is in the Box

Please inspect all items upon delivery.

• Siemens 3RW4076-6BB44 SIRIUS S12 soft starter.

• Busbar connections for main circuit.

• Screw terminals for auxiliary and control circuits.

• Installation instruction manual.

Frequently Asked Questions (FAQ)

1. Is the 3RW4076-6BB44 still available for purchase?

The 3RW4076-6BB44 is a phased-out product. Siemens recommends the successor type 3RW5076-6AB14 from the SIRIUS 3RW5 series.

2. What is the operational current rating of this soft starter?

The 3RW4076-6BB44 is rated at 432A at 40°C. At 50°C, the rating is 385A. At 60°C, the rating is 335A.

3. Does this soft starter include an integrated bypass?

Yes. The 3RW4076-6BB44 includes an integrated bypass contact system. This reduces power loss during continuous operation.

4. What is the control supply voltage requirement?

The 3RW4076-6BB44 requires a 230V AC control supply at 50 or 60 Hz. Voltage tolerance is -15% to +10%.

5. What is the protection class of this device?

The 3RW4076-6BB44 has a protection class of IP00. Therefore, it must be installed in an appropriate enclosure.