Siemens 5SY6125-7CC 5SY Miniature Circuit Protection Switch 1P 25A

The Siemens 5SY6125-7CC 5SY Miniature Circuit Breaker (MCB) stands as a robust solution for reliable overcurrent protection in electrical installations. This single-pole, 25-ampere device offers superior tripping characteristics and robust construction, ensuring operational safety and equipment longevity. Its key advantages include high breaking capacity, enhanced protection against short circuits and overloads, and compliance with stringent international standards. Core features encompass a precise tripping mechanism, durable arc-quenching capabilities, and a compact design suitable for various distribution boards and enclosures. Technically, the Siemens 5SY6125-7CC operates at a rated voltage of 230/400V AC, with a tripping curve of C, and a breaking capacity (Icn) of 6kA. Its insulation voltage (Ui) is 500V AC, and it conforms to IEC/EN 60898-1 and IEC/EN 60947-2 standards, underscoring its industrial-grade performance.

Product Specifications

| Feature                  | Specification                           |

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

| Product Type             | Miniature Circuit Breaker (MCB)         |

| Siemens Product Series   | 5SY Series                              |

| Model Number             | 5SY6125-7CC                             |

| Number of Poles          | 1                                       |

| Rated Current (In)       | 25 A                                    |

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

| Tripping Characteristic  | C Curve                                 |

| Breaking Capacity (Icn)  | 6 kA                                    |

| Insulation Voltage (Ui)  | 500 V AC                                |

| Frequency                | 50/60 Hz                                |

| Housing Material         | Thermosetting Plastic                   |

| Mounting Type            | DIN Rail (35mm)                         |

| Protection Class         | IP20 (finger-safe)                      |

| Operating Temperature    | -25 to +45 °C                           |

| Standards Compliance     | IEC/EN 60898-1, IEC/EN 60947-2          |

Core Features & Market Positioning

The Siemens 5SY6125-7CC differentiates itself through its exceptionally reliable tripping mechanism, crucial for preventing equipment damage and ensuring personnel safety in demanding industrial environments. Its C-curve characteristic is specifically designed to handle moderate inrush currents associated with inductive loads, such as motors and transformers, without nuisance tripping, while still providing robust protection against short circuits. This makes it a preferred choice over B or D curve breakers in many mixed-load applications. Furthermore, Siemens' reputation for quality and longevity positions the 5SY6125-7CC as a premium component within the miniature circuit protection market, offering peace of mind and reduced long-term maintenance costs for discerning users who prioritize dependability and performance.

Key Application Scenarios

This 1P 25A MCB is ideally suited for a broad spectrum of industrial and commercial applications where precise and dependable overcurrent protection is paramount. It finds extensive use in distribution boards for machine tools, control cabinets for automation systems, and general power distribution within manufacturing facilities. The 5SY6125-7CC is particularly effective in protecting circuits feeding equipment with moderate inductive loads, such as small to medium-sized motors, solenoid valves, and lighting systems that might experience temporary inrush currents. Its robust construction also makes it a suitable choice for environments requiring high reliability, including process control and facility management systems.

Practical System Integration Guidance

Integrating the Siemens 5SY6125-7CC into existing or new electrical systems is straightforward, leveraging standard DIN rail mounting. Ensure the main power supply is de-energized before commencing any work. Connect the incoming power supply to the line side terminal (typically marked with 'L' or an arrow indicating input) and the outgoing load to the load side terminal (typically marked with 'Load' or an arrow indicating output). The MCB is designed for easy snap-on installation onto a standard 35mm symmetrical top-hat DIN rail. It is imperative to use correctly sized conductors terminated with appropriate cable lugs or ferrules to ensure a secure and low-resistance connection, minimizing the risk of overheating. Adherence to local electrical codes and standards is essential throughout the installation process.

Operation and Risk Mitigation

The Siemens 5SY6125-7CC operates automatically to interrupt the circuit when an overcurrent (overload or short circuit) condition is detected, safeguarding connected equipment and preventing fire hazards. The C-curve tripping characteristic provides a delayed trip for inrush currents up to 5-10 times the rated current, while still offering rapid disconnection for short circuits. In the event of a trip, the lever on the front of the MCB will move to the 'OFF' position. To reset, ensure the fault condition has been cleared, then firmly push the lever back to the 'ON' position. Should the breaker trip repeatedly without an obvious fault, it indicates a persistent overload or a potentially failing appliance; consult a qualified electrician. Never attempt to reset a breaker in the presence of visible damage or if it fails to stay in the 'ON' position, as this could indicate a severe internal fault.

Scalability & Long-Term Value

The 5SY series, including the 5SY6125-7CC, offers excellent long-term value due to its compatibility with Siemens' broader range of industrial automation and electrical distribution components. This ensures seamless integration into expanding or evolving electrical infrastructure. While the 5SY6125-7CC is a fixed-rating device, the Siemens ecosystem allows for straightforward replacement or upgrades to higher-rated or specialized MCBs within the same series or compatible product lines should system requirements change. Its durable construction and adherence to international standards mean it performs reliably for many years, reducing the total cost of ownership through minimized downtime and replacement frequency, making it a sound investment for robust electrical protection.

Frequently Asked Questions

What is the tripping characteristic of the Siemens 5SY6125-7CC?

The Siemens 5SY6125-7CC features a Type C tripping characteristic. This means it is designed to trip when the current exceeds 5 to 10 times its rated current (25A). It is suitable for circuits with moderate inrush currents, such as those powering motors or transformers.

Can the Siemens 5SY6125-7CC be used for motor protection?

Yes, the Type C characteristic makes it suitable for protecting circuits with motors. It can handle the temporary high inrush current when a motor starts up. However, for direct motor protection, a dedicated overload relay might offer more precise thermal protection.

What is the breaking capacity of the Siemens 5SY6125-7CC?

The Siemens 5SY6125-7CC has a breaking capacity (Icn) of 6 kA. This indicates its ability to safely interrupt fault currents up to 6,000 amperes. It is designed for use in installations where the prospective short-circuit current does not exceed this level.

What are the main advantages of using a Siemens 5SY6125-7CC MCB?

Key advantages include reliable overcurrent and short-circuit protection. It offers a C-curve characteristic ideal for inductive loads, preventing nuisance tripping. Siemens products are known for their durability and compliance with international safety standards.

How do I install the Siemens 5SY6125-7CC miniature circuit breaker?

Install it on a standard 35mm DIN rail, ensuring the incoming power is connected to the line side and the outgoing load to the load side. Always de-energize the circuit before installation for safety. Use appropriately sized conductors and terminations for secure connections.

What does the '1P' in 5SY6125-7CC signify?

'1P' signifies that it is a single-pole miniature circuit breaker. This means it is designed to protect a single electrical conductor. Single-pole breakers are commonly used for lighting circuits or in single-phase power distribution.

What is the rated current of the Siemens 5SY6125-7CC?

The rated current for this specific model is 25 Amperes (A). This is the maximum continuous current the breaker can carry without tripping. It should be selected based on the load requirements of the circuit it is protecting.

Is the Siemens 5SY6125-7CC compliant with relevant safety standards?

Yes, the 5SY6125-7CC complies with IEC/EN 60898-1 and IEC/EN 60947-2 standards. These are internationally recognized safety and performance standards for circuit protection devices. Compliance ensures the product meets rigorous testing requirements for electrical safety.

What is the operating voltage range for the Siemens 5SY6125-7CC?

The rated operating voltage (Ue) for this MCB is 230/400 Volts AC. It is suitable for use in both single-phase (230V) and three-phase (400V) distribution systems. Always ensure the system voltage matches the breaker's rating for proper function.

Where is the Siemens 5SY6125-7CC typically used in industrial applications?

It is commonly used in industrial control cabinets and power distribution boards. Applications include protecting circuits for machine tools, automation equipment, and general facility power. Its C-curve makes it suitable for loads with moderate inrush currents.