Siemens 5SY6402-7CC Miniature Protection Circuit Breaker 4P 2A

The Siemens 5SY6402-7CC Miniature Protection Circuit Breaker (4P, 2A) stands as a robust solution for overcurrent and short-circuit protection across various industrial and commercial applications. Engineered with Siemens' renowned quality and reliability, this 4-pole, 2-ampere circuit breaker offers superior safety and operational continuity. Its compact design and advanced tripping characteristics ensure precise power distribution management, safeguarding sensitive equipment from electrical faults. Key technical parameters include a rated voltage of 400V AC, a breaking capacity of 6kA, and compliance with IEC/EN 60898-1 standards, underscoring its suitability for demanding electrical environments.

Product Specifications

| Feature             | Specification             |

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

| Product Type        | Miniature Circuit Breaker |

| Manufacturer        | Siemens                   |

| Series              | 5SY6                      |

| Poles               | 4                         |

| Rated Current       | 2 A                       |

| Rated Voltage       | 400 V AC                  |

| Breaking Capacity   | 6 kA                      |

| Tripping Curve      | C                         |

| Frequency           | 50/60 Hz                  |

| Protection Class    | IP20                      |

| Terminal Type       | Screw Terminal            |

| Mounting            | DIN Rail                  |

| Standard           | IEC/EN 60898-1           |

| Ambient Temp Range  | -25 to +45 °C             |

Core Features & Market Positioning

The Siemens 5SY6402-7CC distinguishes itself through its precise C-curve tripping characteristic, ideal for protecting circuits with moderate inrush currents, such as motors and fluorescent lighting. This feature minimizes nuisance tripping while ensuring prompt disconnection during fault conditions, a critical advantage in industrial settings where operational uptime is paramount. Its 6kA breaking capacity provides a high level of protection against short circuits, exceeding the requirements for many standard installations. As part of Siemens' extensive range of circuit protection devices, the 5SY6 series benefits from decades of innovation, positioning it as a reliable and cost-effective choice for professionals seeking dependable electrical safety and distribution.

Key Application Scenarios

This 2A, 4-pole circuit breaker is exceptionally well-suited for protecting individual circuits within control panels, distribution boards, and machine enclosures. Common applications include safeguarding small inductive loads, control circuits for automation systems, and general power distribution in commercial buildings. Its 4-pole configuration makes it ideal for three-phase applications where all active conductors require simultaneous disconnection for safety, such as in motor control centers or HVAC systems. Industries benefiting from the 5SY6402-7CC include manufacturing, building automation, and infrastructure projects requiring reliable, compact overcurrent protection.

Practical System Integration Guidance

Integrating the Siemens 5SY6402-7CC into existing electrical systems is straightforward due to its standard DIN rail mounting. The robust screw terminals ensure secure connections for incoming and outgoing power, accommodating appropriate wire gauges for the 2A rating. When wiring, ensure that the load side is connected to the breaker's output terminals and the line side to the input. For three-phase systems, connect the appropriate phases to the designated poles, ensuring correct phase rotation if applicable to the downstream equipment. Proper torque applied to the terminals prevents loose connections, which can lead to overheating and potential faults.

Operation and Risk Mitigation

Operating the Siemens 5SY6402-7CC is intuitive, with a clear ON/OFF lever indicating the circuit status. To reset a tripped breaker, identify and rectify the cause of the fault (overload or short circuit), then manually flip the lever to the ON position. The C-curve tripping characteristic means the breaker will trip at 5 to 10 times the rated current. Risk mitigation involves regular visual inspection for signs of damage or overheating and ensuring the breaker is installed in an environment suitable for its IP20 protection rating, away from excessive moisture or dust. Overloading circuits beyond the 2A capacity will inevitably lead to tripping, preventing damage to downstream equipment and wiring.

Scalability & Long-Term Value

The Siemens 5SY6402-7CC offers straightforward scalability for applications requiring protection for multiple circuits. Its compatibility with the broader Siemens ecosystem of industrial control and automation components ensures seamless integration into larger systems. While this specific model is designed for direct circuit protection, it can be part of a larger, intelligent power distribution network when integrated with smart meters or remote monitoring units. This allows for future upgrades to more sophisticated IIoT-enabled solutions that provide real-time data and diagnostics, enhancing operational efficiency and predictive maintenance capabilities.

Frequently Asked Questions

Q1: What is the primary function of the Siemens 5SY6402-7CC?

This circuit breaker's main role is to protect electrical circuits from damage caused by overcurrents, including overloads and short circuits. It acts as an automatic safety switch, rapidly interrupting the power flow when fault conditions are detected.

Its robust design ensures reliable operation in demanding industrial environments, safeguarding sensitive equipment and preventing electrical fires. The 4-pole configuration is particularly useful for three-phase systems requiring complete isolation.

By providing precise tripping characteristics, it prevents nuisance tripping while offering essential protection, thereby minimizing downtime and maintenance costs associated with electrical faults.

Q2: What does the "C" in the tripping curve designation signify?

The "C" designation refers to the breaker's tripping characteristic, indicating that it will trip at a higher inrush current than an "B" curve breaker. Specifically, it trips between 5 to 10 times its rated current.

This makes the 5SY6402-7CC ideal for circuits powering inductive loads like motors, transformers, or fluorescent lighting ballasts, which experience temporary high current surges upon startup. It provides protection without being overly sensitive to these normal inrush currents.

Therefore, a C-curve breaker offers a balance between sensitive protection against short circuits and tolerance for the momentary high currents characteristic of certain types of electrical equipment.

Q3: What is the breaking capacity of the Siemens 5SY6402-7CC and why is it important?

The breaking capacity of this Siemens breaker is 6 kA (kiloamperes). This value represents the maximum fault current the breaker can safely interrupt without sustaining damage.

A higher breaking capacity ensures that the circuit breaker can effectively and safely disconnect the circuit even during severe short-circuit events. This prevents catastrophic damage to the breaker itself and the electrical system.

For most standard residential and commercial installations, a 6kA breaking capacity is sufficient, but it's crucial to ensure it meets or exceeds the prospective fault current at the point of installation as per electrical codes.

Q4: Can the Siemens 5SY6402-7CC be used in three-phase applications?

Yes, the Siemens 5SY6402-7CC is a 4-pole (four-pole) device, making it inherently suitable for use in three-phase electrical systems. In a three-phase setup, all four poles are utilized to disconnect all live conductors simultaneously.

Using a 4-pole breaker in three-phase applications ensures that no current flows through the downstream load even if only one phase experiences a fault or is switched off. This is a critical safety feature for protecting equipment and personnel.

When installing in a three-phase system, ensure proper connection of each phase to its corresponding pole on the breaker and verify correct phase sequence if required by the connected machinery.

Q5: What are the typical environments or industries where this circuit breaker is used?

This specific Siemens circuit breaker finds extensive use in industrial control panels, machine building, and automation systems where precise protection of low-current circuits is necessary. It's commonly employed for safeguarding control transformers, fans, and pumps.

Its compact size and reliable performance also make it suitable for distribution boards in commercial buildings, protecting lighting circuits, socket outlets, or smaller appliances that require individual overcurrent protection.

Industries such as manufacturing, food processing, water treatment, and building management systems frequently utilize breakers like the 5SY6402-7CC for their robust protection capabilities and compliance with safety standards.

Q6: How do I correctly install the Siemens 5SY6402-7CC onto a DIN rail?

Installation involves snapping the breaker onto a standard 35mm DIN rail. Ensure the rail is securely mounted and properly grounded. The breaker typically has a clip at the rear that engages with the rail.

First, connect your incoming power conductors to the line-side terminals of the breaker (usually marked "L" or with arrow indicators). Then, connect the outgoing conductors to the load-side terminals. Ensure all connections are tightened securely with the appropriate torque.

Before energizing the circuit, double-check all wiring for correctness and ensure no stray wires are present. Verify that the breaker is correctly seated on the DIN rail and that the rail itself is properly grounded.

Q7: What voltage and frequency ratings should I consider for this breaker?

The Siemens 5SY6402-7CC is rated for a maximum operating voltage of 400V AC. It is designed to function reliably within standard industrial power systems operating at 50 Hz or 60 Hz.

It is crucial to match the breaker's voltage rating to the system voltage. Using a breaker with a lower voltage rating than the system can lead to insulation breakdown and failure. The frequency rating ensures stable operation within typical power grid frequencies.

Always confirm the system voltage and frequency at your installation site and ensure they are within the specified operating limits of the 5SY6402-7CC to guarantee safe and effective performance.

Q8: What is the difference between a C-curve and other tripping curves (e.g., B or D)?

The primary difference lies in the inrush current handling capability. A B-curve trips between 3-5 times the rated current, suitable for purely resistive loads. A C-curve trips between 5-10 times, ideal for moderate inductive loads.

A D-curve trips between 10-20 times the rated current, designed for high inrush currents like large motors or X-ray equipment. The choice depends on the specific characteristics of the connected load to prevent nuisance tripping.

Selecting the correct tripping curve is essential for both safety and operational efficiency. An incorrectly chosen curve can lead to unnecessary shutdowns or inadequate protection against faults.

Q9: What does the IP20 protection class mean for this breaker?

IP20 signifies that the circuit breaker is protected against solid objects greater than 12.5 mm in diameter, such as fingers. It offers a basic level of protection against accidental contact with live parts.

However, IP20 protection does not guard against moisture or water ingress. Therefore, this breaker is intended for use in dry indoor environments where there is no risk of water splashing or high humidity.

Installation should be within enclosures, control cabinets, or distribution boards that provide additional environmental protection suitable for the intended application.

Q10: Where can I find technical documentation or datasheets for the Siemens 5SY6402-7CC?

Official technical documentation, including detailed datasheets and user manuals, can typically be found on the Siemens Industry Online Support (SIOS) portal. You will need to search using the product number "5SY6402-7CC".

Distributors and electrical supply wholesalers that carry Siemens products often provide access to these datasheets on their websites. Searching their product pages for the specific breaker number usually yields downloadable PDF resources.

For specific application queries or if you encounter difficulties locating documentation, contacting Siemens technical support directly or your local Siemens representative is recommended for expert assistance.