Siemens 3RT1955-4G Contactor Terminal Connector Block

The Siemens 3RT1955-4G is a critical component designed to enhance the connectivity and functionality of Siemens Sirius contactors. This frame terminal block, specifically engineered for the 3RT1054 size S6 contactor and compatible with overload relay 3RB105, offers robust connections for conductors up to approximately 70 mm². Its primary advantage lies in providing a secure and efficient termination point, simplifying wiring and ensuring reliable electrical contact within demanding industrial environments. The product's active lifecycle status and adherence to RoHS directive since 2006 highlight its established presence and commitment to environmental standards.

Product Specifications

| Feature                | Specification                                       |

| :--------------------- | :-------------------------------------------------- |

| Product Number         | 3RT1955-4G                                          |

| Product Brand Name     | SIRIUS                                              |

| Product Category       | Terminal Covers / Frame Terminal Block              |

| Compatibility          | Contactor 3RT1054 size S6, 3RT1055 size S6, 3RB105 |

| Max. Connection        | Approx. 70 mm² (Solid or stranded, finely stranded) |

| AWG Cable Size         | 2x 1/0 for main contacts                            |

| Packaging Dimensions   | 102.00 x 85.00 x 28.00 mm                           |

| Net Weight             | 0.240 Kg                                            |

| RoHS Compliance        | Yes, since 07/01/2006                               |

| Country of Origin      | Germany                                             |

| Product Lifecycle      | Active Product (PM300)                              |

Core Features & Market Positioning

The Siemens 3RT1955-4G distinguishes itself through its specialized design as a "box terminal block," offering a secure and high-capacity connection point essential for heavy-duty applications. Its positioning within the Siemens SIRIUS industrial control system ecosystem underscores its reliability and integration capabilities. The product is engineered for demanding industrial environments where secure and stable electrical connections are paramount. It serves as a key accessory, extending the utility of compatible Siemens contactors and overload relays by facilitating the connection of larger gauge conductors, thereby simplifying complex electrical assemblies and enhancing overall system integrity.

Key Application Scenarios

The Siemens 3RT1955-4G terminal connector block is indispensable in various industrial settings requiring robust motor control and power distribution. Its primary application is in conjunction with Siemens 3RT1054 and 3RT1055 size S6 contactors, as well as the 3RB105 overload relay, particularly where high current loads and substantial conductor sizes (up to 70 mm²) are involved. This includes applications in heavy manufacturing, process industries, building automation, and any scenario demanding reliable power switching and protection for high-power machinery. Its design facilitates the secure termination of solid, stranded, and finely stranded conductors, ensuring stable connections for critical circuits.

Practical System Integration Guidance

Integrating the Siemens 3RT1955-4G into existing control systems is straightforward, leveraging its design for direct compatibility with specified Siemens contactors and overload relays. The terminal block is designed for screw termination, accommodating conductor cross-sections up to 70 mm². For solid or stranded conductors, a maximum of 1x 50 mm² or 1x 70 mm² can be connected. For finely stranded conductors with core end processing, the same maximums apply. Additionally, it supports up to 2x 1/0 AWG cables for main contacts. Proper torque must be applied to the terminal screws to ensure a secure connection, preventing potential faults. Users should refer to the relevant Siemens SIRIUS documentation for detailed wiring diagrams and installation best practices to ensure optimal performance and safety.

Operation and Risk Mitigation

Safe and effective operation of the Siemens 3RT1955-4G terminal connector block relies on adherence to proper installation and usage guidelines. It is designed to be used exclusively with compatible Siemens contactors and overload relays, such as the 3RT1054, 3RT1055, and 3RB105, to ensure electrical and mechanical integrity. Misapplication or use with incompatible devices can lead to system failure, electrical hazards, or damage to equipment. Users must ensure that conductors are correctly stripped and inserted into the terminal block before tightening the screws to the specified torque. Regular inspection of connections for signs of wear, corrosion, or looseness is recommended to mitigate risks associated with electrical faults and ensure the longevity of the system.

Scalability & Long-Term Value

The Siemens 3RT1955-4G terminal connector block, as part of the broader Siemens SIRIUS industrial control and automation portfolio, offers significant long-term value through its inherent compatibility and the scalability of the SIRIUS system. Its robust construction and adherence to international standards ensure reliable performance over extended periods, minimizing the need for premature replacements. While the 3RT1955-4G itself is a connectivity accessory, its integration with contactors and relays that are often part of larger, modern automation architectures, means it benefits from the inherent upgrade paths within the SIRIUS line. This facilitates seamless integration with newer control technologies, including digital communication modules and IIoT platforms, supporting the evolution of smart manufacturing environments.

Frequently Asked Questions (FAQs)

What contactors is the Siemens 3RT1955-4G compatible with?

The Siemens 3RT1955-4G frame terminal block is specifically designed for use with Siemens SIRIUS contactors of size S6, primarily the 3RT1054 and 3RT1055 models. It is also compatible with the 3RB105 overload relay.

This ensures a secure mechanical and electrical fit, crucial for reliable operation in industrial applications. Using it with non-specified contactors may lead to improper connections or system failures.

Always consult the Siemens product documentation to confirm compatibility for specific project requirements and ensure optimal system performance and safety.

What is the maximum conductor size supported by the 3RT1955-4G?

This terminal block supports a maximum connection of approximately 70 mm² for main contacts. For solid or stranded conductors, you can connect up to 1x 50 mm² or 1x 70 mm².

For finely stranded conductors, provided they have core end processing, the maximum is also 1x 50 mm² or 1x 70 mm². It also accommodates up to 2x 1/0 AWG cables.

Ensuring the correct conductor size and proper termination is vital for safe and efficient power transmission, preventing overheating and potential failures.

How do I properly install the Siemens 3RT1955-4G terminal block?

Installation involves securely attaching the terminal block to the compatible Siemens contactor or overload relay. Ensure conductors are correctly stripped and inserted into the designated terminal openings before tightening the screws.

Use a calibrated torque wrench to tighten the terminal screws to the manufacturer's recommended torque specification. This ensures a firm connection and prevents loosening due to vibration.

Always refer to the official Siemens installation manual for detailed instructions, wiring diagrams, and safety precautions specific to the 3RT1955-4G and its associated devices.