Siemens 5SY6340-8CC Heavy Duty Circuit Breaker for Power Systems 3P 40A

The Siemens 5SY6340-8CC is a robust, three-pole miniature circuit breaker designed for demanding power system applications. It offers reliable protection with a 6kA breaking capacity and a D-type tripping characteristic, suitable for circuits with high inrush currents. This heavy-duty device ensures operational safety and system integrity.

Product Specifications

| Feature                     | Specification                                   |

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

| Product Number              | 5SY6340-8CC                                     |

| Type                        | Miniature Circuit Breaker                       |

| Poles                       | 3P (Three-Pole)                                 |

| Rated Voltage (AC)          | 400 V                          |

| Rated Current               | 40 A                           |

| Breaking Capacity (Icu/Icn) | 6 kA                              |

| Tripping Characteristic     | D                              |

| Insulation Voltage (Ui)     | 440 V                          |

| Degree of Pollution         | 3                              |

| Installation Depth          | 70 mm                                 |

| Mounting Type               | Quick assembly system                 |

| Terminal Tightening Torque  | 2.5 - 3 N·m; 3.5 Nm max. |

| Ambient Temperature         | -25 °C to +55 °C                      |

| Net Weight                  | 0.480 Kg / 479 g            |

| Country of Origin           | China                                 |

| Compliance                  | RoHS directive, IEC/EN 60898-1, IEC/EN 60947-2 |

Core Features & Market Positioning

The Siemens 5SY6340-8CC distinguishes itself through its heavy-duty construction and reliable D-type tripping characteristic. This makes it exceptionally well-suited for protecting electrical equipment that experiences high starting currents, such as motors, transformers, and certain lighting systems. Its 6kA breaking capacity offers robust protection against short circuits in typical industrial and commercial power distribution networks. Positioned as a dependable component within Siemens' SENTRON product line, it embodies the brand's commitment to quality, safety, and operational efficiency in low-voltage electrical installations. The product's active lifecycle status indicates ongoing support and availability from Siemens.

Key Application Scenarios

This circuit breaker is a critical component in various industrial and commercial power systems. Its primary applications include:

  Motor Protection: The D-curve characteristic is ideal for protecting electric motors, as it allows for the higher temporary currents drawn during startup without nuisance tripping.  Transformer Protection: Similar to motor protection, transformers also exhibit high inrush currents, making the 5SY6340-8CC a suitable choice for their protection.  Power Distribution Panels: It serves as a reliable overcurrent and short-circuit protection device in main distribution boards and sub-distribution panels within factories, commercial buildings, and infrastructure projects.  Heavy Machinery: Applications involving heavy machinery that draws significant power will benefit from the breaker's robust performance characteristics.

Practical System Integration Guidance

Proper installation is paramount for the safe and effective operation of the Siemens 5SY6340-8CC. It is designed for quick assembly system mounting. The terminal connections are suitable for solid and stranded conductors, with a generous cross-section range from 0.75 mm² to 35 mm² for solid conductors, and up to 25 mm² for finely stranded conductors with core end processing. Adherence to the specified tightening torque for screw-type terminals (2.5-3 N·m or 3.5 Nm max.) is crucial to ensure secure connections and prevent overheating. The device's compact design with 3 module width units allows for efficient use of space in distribution boards. Always consult the official Siemens installation guidelines and manuals for detailed instructions and any specific wiring requirements.

Operation and Risk Mitigation

The Siemens 5SY6340-8CC operates automatically, disconnecting the circuit when an overcurrent or short-circuit condition is detected, thereby preventing damage to equipment and mitigating fire hazards. Its D-type tripping characteristic means it is designed to withstand higher inrush currents, reducing the risk of nuisance tripping in applications like motor starts. As with all electrical installations, risks can be mitigated through correct installation, regular inspection, and ensuring that the circuit breaker is appropriately rated for the load it protects. The IP20 protection class indicates that it is protected against solid objects larger than 12.5mm and requires connection of conductors for full protection. It is vital to ensure that maintenance and troubleshooting are performed by qualified personnel.

Scalability & Long-Term Value

While the 5SY6340-8CC is a standalone miniature circuit breaker, its value lies in its integration within the broader Siemens SENTRON system. This ensures compatibility with other Siemens low-voltage components and distribution systems. The product's active status indicates continued Siemens support. For future upgrades or system expansions, Siemens offers a comprehensive portfolio of protection and switching devices, enabling seamless integration and scalable power management solutions. The availability of documentation such as datasheets, manuals, and certificates further supports long-term maintenance and system planning.

Frequently Asked Questions (FAQs)

Q1: What is the primary advantage of the D-type tripping characteristic in the Siemens 5SY6340-8CC?

The D-type characteristic allows for higher inrush currents. This is vital for inductive loads like motors and transformers. It prevents nuisance tripping during startup.

This feature ensures reliable operation for equipment with significant temporary current demands. It is a key differentiator for specific industrial applications.

The 5SY6340-8CC's D-curve makes it ideal for motor protection circuits. It safeguards equipment effectively against faults.

Q2: What is the breaking capacity of the Siemens 5SY6340-8CC and what does it signify?

This breaker has a breaking capacity of 6 kA. It indicates the maximum fault current it can safely interrupt.

This ensures protection against severe short-circuit events in power systems. It meets standard IEC and EN requirements.

A higher breaking capacity provides greater safety and system reliability. It is crucial for industrial and commercial power distribution.

Q3: Can the Siemens 5SY6340-8CC be used for DC applications?

The primary design is for AC systems. Its specifications focus on AC voltage and frequency ranges.

While some breakers can handle DC, this model's datasheet primarily lists AC ratings. Always verify specific DC application suitability.

For DC circuits, it is recommended to use breakers explicitly rated and designed for DC operation. Consult Siemens documentation for alternatives if needed.

Q4: What types of conductors can be connected to the Siemens 5SY6340-8CC?

It accepts solid and stranded conductors. The cross-section range is broad for flexibility.

For solid conductors, sizes 0.75 mm² to 35 mm² are supported. Finely stranded conductors up to 25 mm² can be used.

Ensure proper conductor preparation and tightening torque for secure, reliable connections.

Q5: What are the environmental operating conditions for the Siemens 5SY6340-8CC?

The breaker operates within a temperature range of -25°C to +55°C. Humidity tolerance is up to 95%.

It is designed for a pollution degree of 3. This suits typical industrial and commercial environments.

Storage temperatures can range from -40°C to +75°C. Always refer to the datasheet for full environmental specifications.

Q6: How is the Siemens 5SY6340-8CC mounted and installed?

Installation utilizes a quick assembly system. It mounts easily on standard DIN rails.

The breaker has an installation depth of 70 mm. It requires minimal space in enclosures.

Follow all local electrical codes and Siemens' specific installation guidelines for safe and compliant setup.

Q7: What documentation is available for the Siemens 5SY6340-8CC?

Extensive documentation is available. This includes datasheets and manuals.

Users can access technical specifications, certificates, and installation guides. Downloads are available via Siemens' SiePortal.

This comprehensive support aids in proper integration, operation, and maintenance.

Q8: Is the Siemens 5SY6340-8CC compliant with RoHS?

Yes, the product is compliant with the RoHS directive. This restricts hazardous substances.

This compliance is important for environmental regulations. It ensures suitability for global markets.

The product information also notes REACH compliance regarding lead content.

Q9: What is the warranty or product lifecycle status of the Siemens 5SY6340-8CC?

The 5SY6340-8CC is an active product. This means it is currently supported by Siemens.

Siemens provides ongoing availability and technical support for active products. Consult Siemens for specific warranty terms.

Its active status assures customers of continued product development and service.

Q10: Where can I purchase the Siemens 5SY6340-8CC?

This circuit breaker is available through Siemens distribution partners. It can also be found on industrial component marketplaces.

Online retailers and specialized electrical suppliers often stock this part. Check for local distributors or major online platforms.

Verify seller reputation and product authenticity when purchasing.