Siemens 5SN6140-7CN Industrial Use Miniature Circuit Breaker 1P 40A

The Siemens 5SN6140-7CN is a single-pole, 40-amp miniature circuit breaker (MCB) designed for robust industrial applications. This device offers essential overcurrent protection, safeguarding electrical systems from damage caused by overloads and short circuits. Its compact design and reliable tripping characteristics ensure operational continuity and safety in demanding environments. The 5SN6140-7CN is engineered to meet stringent industrial standards, providing a dependable solution for circuit protection where performance and durability are paramount.

Product Specifications

| Specification                | Value                       |

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

| Product Type                 | Miniature Circuit Breaker   |

| Manufacturer                 | Siemens                     |

| Model Number                 | 5SN6140-7CN                 |

| Number of Poles              | 1                           |

| Rated Current                | 40 A                        |

| Tripping Characteristic      | C                           |

| Breaking Capacity (Icn)      | 6 kA (according to EN 60898) |

| Rated Voltage (AC)           | 230/400 V                   |

| Insulation Voltage (Ui)      | 250 V (single-phase AC)     |

| Overvoltage Category         | III                         |

| Degree of Pollution          | 2                           |

| Mechanical Service Life      | 10,000 switching cycles     |

| Energy Limitation Class      | 3                           |

| Conductor Cross-Section (Solid) | 0.75 - 25 mm²               |

| Conductor Cross-Section (Stranded) | 0.75 - 25 mm²               |

| Tightening Torque            | 2.5 - 3 N·m                 |

| Protection Class             | IP20                        |

| Halogen-Free                 | Yes                         |

| Sealable                     | Yes                         |

| Silicon-Free                 | Yes                         |

Core Features & Market Positioning

The Siemens 5SN6140-7CN distinguishes itself through its reliable performance and adherence to high industrial safety standards. As part of Siemens' SENTRON product line, it benefits from the brand's long-standing reputation for quality and innovation in electrical engineering. This MCB is positioned as a dependable solution for essential circuit protection, particularly in industrial settings where consistent operation and safety are non-negotiable. Its Type C tripping characteristic makes it suitable for applications with moderate inrush currents, such as those found in motor control or lighting circuits, offering a good balance between sensitivity to faults and immunity to transient surges. The inclusion of features like halogen-free and silicon-free materials also aligns with growing environmental and safety regulations in industrial manufacturing.

Key Application Scenarios

The Siemens 5SN6140-7CN is ideally suited for a wide range of industrial applications requiring reliable single-pole circuit protection. Its 40A rating and Type C tripping curve are particularly effective in safeguarding circuits within manufacturing plants, process control systems, and electrical distribution boards. Common use cases include protecting individual machines, control panels, and localized power distribution circuits that may experience moderate inductive or capacitive loads. It is also a robust choice for protecting sensitive electronic equipment that requires precise overcurrent detection without nuisance tripping. Industries such as chemical processing, automotive manufacturing, and building automation frequently utilize MCBs with these specifications for ensuring operational integrity.

Practical System Integration Guidance

Integrating the Siemens 5SN6140-7CN into an industrial electrical system is straightforward, owing to its standard design for DIN rail mounting and clear terminal markings. Ensure that the incoming power supply is de-energized before commencing any installation work. The breaker connects to the power source at the line side (typically the top terminals) and feeds the protected circuit from the load side (bottom terminals). Use solid or stranded conductors within the specified cross-section range of 0.75 mm² to 25 mm². A tightening torque of 2.5 to 3 N·m should be applied to the screw-type terminals to ensure a secure and reliable connection, preventing overheating and potential faults. For systems requiring monitoring or remote control, the 5SN6140-7CN can be supplemented with compatible Siemens ancillary devices, such as auxiliary contacts or shunt releases.

Operation and Risk Mitigation

Proper operation of the Siemens 5SN6140-7CN relies on understanding its tripping mechanisms. It will automatically interrupt the circuit when an overload condition (current exceeding the rated value for a sustained period) or a short circuit (a sudden, very high current flow) occurs. A visible indication on the breaker handle, typically shifting to the "OFF" position, signals a tripped state. To reset the breaker after a fault has been cleared, simply move the handle to the "OFF" position and then firmly back to the "ON" position. To mitigate risks, always ensure the breaker's rated breaking capacity (6 kA) is sufficient for the potential fault currents in the system. Avoid operating the breaker with a damaged handle or enclosure. Regular visual inspections can identify potential issues, and ensuring correct conductor termination prevents loose connections that can lead to arc faults.

Scalability & Long-Term Value

The Siemens 5SN6140-7CN offers significant long-term value through its compatibility with a broad ecosystem of Siemens automation and power distribution components. Its modular design allows for easy replacement or addition of functions through plug-in accessories, enhancing system flexibility. This MCB integrates seamlessly with other Siemens SENTRON products, ensuring a cohesive and reliable electrical infrastructure. For facilities looking to adopt Industry 4.0 principles, these breakers can be part of a larger smart grid solution, often managed through intelligent energy monitoring systems that collect data for predictive maintenance and optimized energy usage. The robust construction ensures a long operational lifespan, minimizing the need for frequent replacements and contributing to overall system reliability and cost-effectiveness.

FAQs

Q1: What is the breaking capacity of the Siemens 5SN6140-7CN?

The Siemens 5SN6140-7CN has a breaking capacity of 6 kA. This rating indicates the maximum fault current it can safely interrupt. It meets standards such as EN 60898.

This capacity is crucial for industrial environments where fault currents can be significant. It ensures the breaker will reliably trip without causing damage to itself or the system.

Consideration of the prospective fault current at the installation point is vital for proper selection. The 6 kA rating is suitable for many standard industrial applications.

Q2: What type of loads can the Siemens 5SN6140-7CN protect?

This breaker features a Type C tripping characteristic. This means it is designed for circuits with moderate inrush currents. Examples include lighting and motor loads.

Type C provides a balance between protecting against overloads and avoiding nuisance tripping from temporary surges. It's ideal for inductive loads.

Ensure your load's inrush current profile aligns with Type C characteristics for optimal performance and protection.

Q3: Can the Siemens 5SN6140-7CN be used in DC systems?

The primary design is for AC systems, with a rated voltage of 230/400V AC. It has an insulation voltage (Ui) of 250V AC for single-phase operation.

While it has a DC rated voltage of up to 72V, its primary application and certification are for AC power distribution. Use in DC systems requires careful consideration and may not be certified.

For dedicated DC applications, it is best to consult specific Siemens DC circuit breaker offerings. Always verify system compatibility for safety and compliance.

Q4: What is the maximum conductor size for the Siemens 5SN6140-7CN?

The breaker accepts solid or stranded conductors up to 25 mm². This size range is quite versatile for industrial wiring.

Secure connections are ensured with the specified tightening torque of 2.5 to 3 N·m. This prevents loose connections and potential issues.

Always use appropriate tools and techniques to strip and terminate conductors for reliable electrical contact.

Q5: Is the Siemens 5SN6140-7CN suitable for residential use?

While technically capable, this model is designed and marketed for industrial applications. Its specifications align with industrial power distribution needs.

Industrial-grade breakers often have specific features and certifications tailored for harsher environments. This can differ from residential MCBs.

For residential installations, it's generally recommended to use breakers explicitly designed and certified for home use.

Q6: What are the environmental features of the Siemens 5SN6140-7CN?

This MCB is specified as halogen-free and silicon-free. It also features a degree of pollution of 2.

These environmental attributes are important for safety and compliance in certain industrial settings. They contribute to a cleaner operational environment.

The IP20 protection class means it is protected against solid objects larger than 12.5mm. It requires enclosure for protection against water.

Q7: How do I reset a tripped Siemens 5SN6140-7CN?

First, ensure the fault condition that caused the trip has been resolved. Then, move the breaker handle fully to the "OFF" position.

Finally, move the handle firmly back to the "ON" position to reset the breaker. A clear visual indication on the handle shows its state.

If the breaker trips repeatedly, investigate the cause of the fault. Continuous tripping indicates an ongoing issue that needs addressing.

Q8: Can supplementary devices be added to the 5SN6140-7CN?

Yes, this miniature circuit breaker supports the installation of supplementary devices. These can enhance functionality.

Examples include auxiliary contacts for remote signaling or shunt releases for remote tripping. This allows for integration into more complex control systems.

Always ensure any add-on devices are compatible with the specific Siemens 5SN6140-7CN model.

Q9: What standards does the Siemens 5SN6140-7CN comply with?

It complies with key international standards for circuit protection. This includes EN 60898 and IEC 60898.

These certifications ensure the breaker meets rigorous safety and performance requirements for its intended applications. Adherence to standards is critical for reliability.

The product also adheres to UL 1077 and CSA C22.2 No.235 for specific markets if applicable.

Q10: What is the energy limitation class of this breaker?

The Siemens 5SN6140-7CN is classified under Energy Limitation Class 3. This relates to its ability to limit the energy let through during a short circuit event.

Class 3 indicates a high level of energy limitation. This protects downstream components from damaging thermal and electrical stress.

This characteristic is important for ensuring the overall safety and longevity of the electrical installation.