Siemens 5SY6304-8CC Four Pole Surge Protection Circuit Breaker 3P 4A

The Siemens 5SY6304-8CC is a robust four-pole surge protection circuit breaker engineered for demanding industrial environments, offering superior overcurrent and short-circuit protection. With a rated current of 4A and a breaking capacity of 6kA, this device ensures reliable safeguarding of electrical circuits in a compact, DIN-rail mountable form factor. Its advanced tripping mechanism provides rapid disconnection, crucial for preventing damage to sensitive equipment and ensuring operational continuity.

Product Specifications

| Feature                 | Specification                               |

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

| Product Type            | Surge Protection Circuit Breaker            |

| Number of Poles         | 4                                           |

| Rated Current (In)      | 4A                                          |

| Rated Voltage (Un)      | 400V AC                                     |

| Breaking Capacity (Icn) | 6kA                                         |

| Tripping Characteristic | Curve C                                     |

| Frequency               | 50/60 Hz                                    |

| Mounting Type           | DIN Rail                                    |

| Protection Class        | IP20                                        |

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

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

Core Features & Market Positioning

The Siemens 5SY6304-8CC distinguishes itself through its specific design for surge protection integrated with circuit breaking capabilities, a critical combination for safeguarding downstream electrical installations. Unlike standard miniature circuit breakers, its inclusion of surge protection elements offers an additional layer of defense against transient overvoltages, which are common in industrial settings due to switching operations or external events like lightning strikes. This dual functionality simplifies panel design and reduces the need for separate surge protective devices (SPDs) in certain applications, positioning it as a cost-effective and space-saving solution. The curve C tripping characteristic is ideal for inductive loads, providing a balance between protection and nuisance tripping. Siemens' reputation for quality and reliability further solidifies its market position as a trusted component for critical infrastructure.

Key Application Scenarios

This four-pole circuit breaker is exceptionally well-suited for protecting three-phase power distribution systems, particularly where sensitive electronic equipment is present. Common applications include control panels in manufacturing plants, building automation systems, telecommunications infrastructure, and renewable energy installations like solar inverters. Its 4A rating makes it ideal for circuits with lower current demands, such as control circuits, lighting circuits, or smaller motor loads that require both overcurrent and surge protection. Users often search for solutions to protect AC drives, programmable logic controllers (PLCs), and variable frequency drives (VFDs) from electrical disturbances, scenarios where the 5SY6304-8CC excels.

Practical System Integration Guidance

Integrating the Siemens 5SY6304-8CC into existing or new electrical systems is straightforward, leveraging standard DIN rail mounting for quick installation. The breaker’s four poles ensure complete isolation of all phases and the neutral conductor in a three-phase system, which is essential for comprehensive protection and safety during maintenance. Ensure proper torque is applied to the screw terminals to prevent loose connections, a common cause of overheating and failure. Wiring should adhere strictly to local electrical codes and standards, with the incoming power connected to the upper terminals and outgoing protected circuits to the lower terminals. For systems requiring coordination with upstream protective devices, understanding its 6kA breaking capacity in relation to the available fault current at the installation point is crucial.

Operation and Risk Mitigation

The Siemens 5SY6304-8CC operates by continuously monitoring the current flow. If an overcurrent or short circuit condition occurs, the thermal or magnetic tripping mechanism rapidly de-energizes the circuit, preventing damage to connected equipment and mitigating fire hazards. The integrated surge protection component activates upon detecting excessive voltage transients, diverting the surge current safely to ground. Proper operation relies on correct installation and ensuring the breaker's rating (4A, 6kA, 400V) is appropriate for the protected circuit. Risks are minimized by performing regular visual inspections of terminals for signs of discoloration or damage, and by ensuring that the breaker is operated within its specified environmental conditions. Always disconnect power before performing any inspection or maintenance.

Scalability & Long-Term Value

The Siemens 5SY6304-8CC offers significant long-term value due to its integration of multiple protective functions and its compatibility with Siemens' broader portfolio of industrial automation and power distribution components. While this specific model is rated at 4A, Siemens offers a wide range of circuit breakers with varying current ratings and tripping characteristics within the 5SY series, allowing for scalable protection solutions as system requirements evolve. Its robust construction is designed for a long operational lifespan, reducing the need for frequent replacements. Furthermore, its adherence to international standards facilitates seamless integration into diverse global projects and ensures backward compatibility with established electrical infrastructure, supporting digitalization initiatives by providing a reliable foundation for smart grid and IIoT applications.

Frequently Asked Questions (FAQs)

What is the primary function of the Siemens 5SY6304-8CC?

This device provides essential overcurrent and short-circuit protection for electrical circuits. It safeguards equipment from damaging current surges and faults.

It also incorporates integrated surge protection, defending against transient voltage spikes. This dual functionality is key for sensitive industrial applications.

The breaker ensures operational continuity and prevents costly damage, making it vital for reliable electrical systems.

Can this circuit breaker be used in residential applications?

While built for industrial robustness, its specifications align with certain demanding residential needs. It is designed for 400V AC systems, common in industrial settings.

For residential use, ensure compliance with local building codes and specific voltage requirements. Standard residential circuits often use lower voltage ratings.

Its four-pole design is typically for three-phase power, which is less common in standard homes but found in some larger properties or specialized areas.

What does the "4A" rating signify for this Siemens breaker?

The "4A" denotes the rated current, meaning it will trip if the continuous current exceeds 4 amperes. This is crucial for protecting circuits with low power consumption.

It ensures that circuits designed for smaller loads are not overloaded, preventing overheating and potential fires. Always match the breaker's rating to the connected load's capacity.

Loads such as control circuits, small motors, or specific electronic devices typically fall within this current range, requiring precise protection.

How does the "Curve C" tripping characteristic affect its operation?

Curve C breakers are designed for circuits with moderate inrush currents, like inductive loads. They offer a balance between overload protection and avoiding nuisance tripping.

This characteristic means the breaker will trip between 5 to 10 times its rated current. It’s suitable for protecting motors, transformers, and lighting systems.

Compared to Curve B (faster for purely resistive loads) or Curve D (slower for very high inrush), Curve C is a versatile choice for many industrial scenarios.

What is the breaking capacity (6kA) and why is it important?

The 6kA breaking capacity indicates the maximum fault current the breaker can safely interrupt without sustaining damage. This is a critical safety parameter.

It must be greater than or equal to the prospective short-circuit current at the point of installation. Installing a breaker with insufficient breaking capacity is extremely dangerous.

This specification ensures that in the event of a severe short circuit, the breaker will reliably disconnect the power, preventing catastrophic failure and potential explosions.

What type of loads is the Siemens 5SY6304-8CC best suited for?

This breaker is ideal for three-phase circuits requiring both overcurrent and surge protection. It's common in industrial automation control panels.

Applications include protecting sensitive electronics like PLCs, VFDs, and control systems where voltage fluctuations are a concern. It also suits smaller three-phase motors or lighting circuits.

Its 4A rating makes it perfect for lower-power auxiliary circuits within larger industrial machinery or distribution boards.

Is this a residual current device (RCD) or an overcurrent protection device?

The Siemens 5SY6304-8CC is primarily an overcurrent protection device, including surge protection. It protects against overloads and short circuits.

It does not provide residual current detection (earth leakage protection) on its own. For RCD functionality, a separate RCD or RCBO (Residual Current Breaker with Overcurrent protection) would be required.

Understanding this distinction is vital for ensuring comprehensive electrical safety, as RCDs protect against electric shock from earth faults.

What are the typical installation requirements for this four-pole breaker?

It mounts on a standard 35mm DIN rail, common in electrical enclosures. Ensure secure mounting for stable electrical contact.

Connections are made via screw terminals. Proper torque is essential to prevent loose connections, which can cause overheating and poor performance.

Wiring must follow local electrical codes. Connect incoming power to the top terminals and outgoing protected circuits to the bottom terminals for proper operation.

Can the surge protection feature be deactivated or bypassed?

Typically, the integrated surge protection components are permanently part of the device and cannot be independently deactivated. They work in conjunction with the circuit breaker.

The surge protection element is designed to activate automatically when a voltage transient exceeds a certain threshold. It diverts excess energy to ground.

Bypassing this feature is not recommended and would negate its protective benefits, leaving the connected equipment vulnerable to surge damage.

What maintenance is recommended for the Siemens 5SY6304-8CC?

Regular visual inspections for any signs of damage or discoloration around the terminals are advisable. Ensure the enclosure is clean.

Periodically check that the breaker is firmly seated on the DIN rail and that all connections are tight, re-torquing if necessary according to manufacturer guidelines.

While these breakers are generally maintenance-free, occasional functional testing (if equipped with test buttons or through isolation and specialized testing) can confirm operational readiness, especially in critical installations.