Siemens 5SY6504-8CC Double Pole Motor Circuit Protection Breaker 1P+N 4A

The Siemens 5SY6504-8CC is a double-pole motor circuit protection breaker designed for robust and reliable electrical system protection. This 1P+N (1 pole + neutral) device operates at 4A, offering critical overcurrent and short-circuit protection for motor circuits and other sensitive electrical installations. Its core advantages lie in its compact design, high breaking capacity, and seamless integration into Siemens' broader SENTRON protection portfolio. Key technical parameters include a rated voltage of 230V AC, a rated short-circuit breaking capacity (Icn) of 6kA at 230V, and a tripping characteristic of 'C', making it suitable for applications where moderate inrush currents are expected. The 'D' characteristic for this model provides enhanced protection against short circuits for inductive loads, while the 1+N pole configuration ensures protection for both the live conductor and the neutral.

Product Specifications

| Specification                       | Value                                                                 |

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

| Product Number                      | 5SY6504-8CC                                                           |

| Type                                | Double Pole Motor Circuit Protection Breaker                          |

| Poles                               | 1P+N (1 Pole + Neutral)                                               |

| Rated Current (In)                  | 4A                                                                    |

| Rated Voltage (Ue)                  | 230V AC                                                               |

| Rated Short-Circuit Breaking Capacity (Icn) | 6kA at 230V AC                                                        |

| Tripping Characteristic             | C (typical), D (for motor protection applications) |

| Width (Number of Modular Spacings)  | 2                                                                     |

| Built-in Depth                      | 70mm                                                                  |

| Degree of Protection (IP)           | IP20                                                                  |

| Voltage Type                        | AC                                                                    |

| Overvoltage Category                | III                                                                   |

| Pollution Degree                    | 3                                                                     |

| Rated Insulation Voltage (Ui)       | 250V                                                                  |

| Rated Impulse Withstand Voltage (Uimp)| 4kV                                                                   |

| Concurrently Switching Neutral Conductor | Yes                                                                   |

| Mechanical Service Life             | Typically 10,000 operating cycles                                     |

Core Features & Market Positioning

The Siemens 5SY6504-8CC is positioned as a reliable and efficient solution for motor protection and general circuit protection within industrial and commercial environments. Its 'C' or 'D' tripping characteristic provides flexibility, with the 'D' characteristic being particularly advantageous for motor applications where transient inrush currents during startup are common. This distinguishes it from standard miniature circuit breakers designed for purely resistive loads. The 1+N pole configuration is a significant feature, offering comprehensive protection by simultaneously switching the neutral conductor, thus enhancing safety and preventing nuisance tripping. The product benefits from Siemens' established reputation for quality and innovation in electrical engineering, placing it as a trusted component within the SENTRON protection family. Key differentiating features include its tool-free mounting capabilities and separate contact position display, enhancing user convenience and operational clarity. Furthermore, its compatibility with Siemens' comprehensive range of accessories, such as busbar terminals, facilitates streamlined system integration.

Key Application Scenarios

The Siemens 5SY6504-8CC finds its primary utility in applications requiring precise motor protection and safeguarding electrical circuits against overloads and short circuits. It is ideally suited for protecting inductive loads, small motor drives, control cabinets, and auxiliary circuits in various industrial sectors. Specific application areas include:

  HVAC and Ventilation Systems: Providing reliable protection for motors driving fans and air handling units, ensuring continuous operation and preventing damage from electrical faults.  Control Cabinets and Automation Systems: Safeguarding sensitive control circuitry and small motors within industrial automation setups, where compact size and high breaking capacity are essential.  Industrial Machinery: Protecting individual motor drives on manufacturing equipment, ensuring operational continuity and minimizing downtime.  Distribution Boards: Serving as a critical protective device in sub-distribution boards for industrial facilities and commercial buildings.  Charging Stations for Electric Vehicles: Offering protection for the control and power circuits within EV charging infrastructure.

Practical System Integration Guidance

Integrating the Siemens 5SY6504-8CC into existing electrical systems is designed to be straightforward. The breaker utilizes standard DIN rail mounting, a ubiquitous standard in industrial electrical panels, ensuring broad compatibility. Its two-module width (70mm) allows for efficient use of panel space. For connections, the unit features double terminal chambers, which accommodate two wires of different cross-sections on each terminal, simplifying wiring and enabling flexible connection options. This feature is particularly useful when connecting multiple conductors or accommodating various wire gauges without requiring specialized adapters. It is crucial to ensure that the incoming power supply is connected to the line terminals and the outgoing load is connected to the load terminals, adhering to correct polarity and wiring practices. For systems requiring busbar distribution, Siemens offers compatible busbar terminals, such as the 5ST3623 and 5ST3653 series, which are designed for 1+N pole configurations and simplify the connection of multiple breakers. Always consult the detailed installation manual provided by Siemens for specific wiring diagrams and safety guidelines.

Operation and Risk Mitigation

Safe operation of the Siemens 5SY6504-8CC relies on understanding its protective functions and adhering to electrical safety standards. The 'C' or 'D' tripping characteristic is designed to differentiate between normal operating currents, temporary inrush currents (like motor startup), and dangerous fault currents. Overload protection is achieved through a thermal tripping mechanism that activates after a delay proportional to the excess current, protecting the motor and connected wiring from gradual overheating. Short-circuit protection is provided by a magnetic tripping mechanism that offers near-instantaneous disconnection upon detecting a significant current surge, preventing catastrophic damage.

To mitigate risks:  Correct Rating Selection: Ensure the breaker's rated current (4A) and tripping characteristic are appropriate for the protected circuit's load and expected inrush currents. Using a breaker with an inadequate rating can lead to nuisance tripping or failure to protect.  Proper Installation: Verify correct wiring and secure connections to prevent loose terminals, which can cause overheating and arcing. Adhere to local electrical codes and standards.  Environmental Considerations: Operate the breaker within its specified ambient temperature range (-25°C to 55°C) and in environments not exceeding the IP20 degree of protection unless appropriate enclosures are used.  Maintenance: Periodically inspect terminals for signs of corrosion or overheating. Although MCBs are generally maintenance-free, visual inspections can identify potential issues.

Scalability & Long-Term Value

The Siemens 5SY6504-8CC, as part of the broader SENTRON product line, offers inherent scalability and long-term value through its modular design and compatibility with a vast ecosystem of Siemens electrical components. While the 5SY6504-8CC itself is a fixed-rating device, its integration into larger Siemens distribution systems allows for system-wide upgrades and expansions. If higher current ratings or different protection characteristics are required for other circuits within the same panel, compatible breakers from the 5SY or other SENTRON series can be easily integrated.

For advanced motor management and integration into Industrial Internet of Things (IIoT) platforms, Siemens offers complementary solutions such as the SIRIUS 3UG5 monitoring relays and the SIMOCODE M-CP motor management system. These systems can work in conjunction with or, in more complex applications, supersede basic MCBs by providing enhanced diagnostics, remote monitoring, and predictive maintenance capabilities. The long-term value is also assured by Siemens' commitment to product lifecycle management and the availability of successor products, such as the 5SY4504-8, ensuring that systems can be maintained and upgraded over time.

Frequently Asked Questions (FAQs)

Q1: What is the main function of the Siemens 5SY6504-8CC breaker?

The Siemens 5SY6504-8CC primarily functions as a miniature circuit breaker (MCB) designed for motor circuit protection. It provides automatic protection against overloads and short circuits, safeguarding connected equipment and electrical installations from damage. Its specific design as a motor circuit protector means it's optimized for loads with higher starting currents.

This device ensures operational safety by quickly disconnecting the power supply when fault conditions are detected. It's crucial for preventing equipment failure, reducing fire hazards, and maintaining system integrity in industrial and commercial applications.

The 1+N pole configuration ensures that both the live conductor and the neutral are switched simultaneously, offering enhanced safety and preventing asymmetrical loads during fault conditions.

Q2: Can the Siemens 5SY6504-8CC be used for general lighting circuits?

While technically capable of protecting lighting circuits, the 5SY6504-8CC is specifically optimized for motor applications with its 'D' tripping characteristic. For standard lighting circuits, which typically have low or no inrush current, a breaker with a 'B' or 'C' characteristic is usually more appropriate and cost-effective.

Using a 'D' characteristic breaker for lighting might lead to nuisance tripping if there are minor, transient voltage fluctuations. It's always best to select an MCB whose tripping characteristic closely matches the expected load profile for optimal performance and reliability.

However, if a lighting circuit is part of a larger system that includes inductive loads or if space is limited and a multi-purpose breaker is desired, the 5SY6504-8CC could be considered, provided its characteristics are well-understood.

Q3: What is the difference between a 'C' and 'D' tripping characteristic on this breaker?

The tripping characteristic defines the magnetic trip current, which is the multiple of the rated current at which the breaker will trip instantly during a short circuit. A 'C' characteristic trips between 5 to 10 times the rated current, suitable for general inductive and capacitive loads with moderate inrush.

A 'D' characteristic trips between 10 to 20 times the rated current. This higher threshold is specifically designed to accommodate the significant inrush currents experienced by motors during startup, preventing premature tripping while still offering rapid protection against severe short circuits.

For motor applications, the 'D' characteristic is generally preferred for the Siemens 5SY6504-8CC, ensuring reliable operation during motor start-up phases.

Q4: Is the Siemens 5SY6504-8CC still available, or is it a discontinued product?

Searches indicate that the Siemens 5SY6504-8CC itself might be considered a "Discontinued Product" or nearing the end of its product lifecycle, with a successor model identified as the 5SY4504-8. However, this does not mean it's entirely unavailable.

Many distributors still stock older or superseded product numbers as long as their inventory lasts. Furthermore, "New" items from sellers like those on eBay might still be available for purchase.

It is advisable to check with major electrical component distributors or Siemens directly for the most current availability status and to identify the recommended successor model for new installations or replacements.

Q5: What type of loads can be protected by the Siemens 5SY6504-8CC?

This breaker is primarily designed for motor circuits and other inductive loads that experience high inrush currents during startup. The 'D' tripping characteristic allows it to handle these transient surges without tripping unnecessarily.

It can also protect general industrial and commercial circuits where a 'C' or 'D' tripping curve is specified. This includes control cabinets, small machinery, and power distribution circuits within an industrial setting.

While it can technically protect resistive loads, it's usually overkill and less cost-effective than breakers with 'B' or 'C' characteristics for purely resistive loads like lighting or heating elements.

Q6: What is the breaking capacity of the Siemens 5SY6504-8CC?

The Siemens 5SY6504-8CC has a rated short-circuit breaking capacity (Icn) of 6 kA according to EN 60898 at 230V AC. It also has a higher rated short-circuit breaking capacity (Icu) of 30 kA according to IEC 60947-2 at 230V AC.

The Icn rating indicates the maximum fault current the breaker can safely interrupt under normal network conditions. The Icu rating is a more severe test condition and represents the ultimate breaking capacity.

This breaking capacity makes it suitable for use in most standard distribution boards and industrial control panels where the prospective short-circuit current does not exceed these limits.

Q7: Can I use the Siemens 5SY6504-8CC in a 120V AC system?

The Siemens 5SY6504-8CC is rated for 230V AC operation. While it might function in a 120V system, it is not optimized for it, and its full performance and protection capabilities may not be realized.

Using a device outside its specified voltage rating can lead to unpredictable behavior and potential failure. It is always recommended to use electrical components within their designed voltage parameters for safety and reliability.

For 120V AC systems, it's best to select circuit breakers specifically designed and rated for that voltage range to ensure proper protection and compliance with electrical codes.

Q8: What are the physical dimensions of the Siemens 5SY6504-8CC?

The Siemens 5SY6504-8CC has a built-in depth of 70mm. Its width is defined by the number of modular spacings it occupies on a DIN rail, which is 2 modules.

Each standard modular unit typically measures 17.5mm in width. Therefore, the breaker occupies approximately 35mm of width on the DIN rail, plus any additional spacing required by the manufacturer's design.

These compact dimensions allow for efficient use of space within electrical enclosures and distribution boards, making it suitable for installations where panel real estate is limited.

Q9: What accessories are compatible with the Siemens 5SY6504-8CC?

The Siemens 5SY6504-8CC is compatible with various SENTRON accessories designed for easy integration. This includes busbar terminals for connecting multiple breakers efficiently in a distribution board.

Examples of compatible busbar terminals include the 5ST3608, 5ST3623, and 5ST3653 series, which are designed for different pole configurations and wire cross-sections, including 1+N pole setups.

Other potential accessories could include auxiliary contacts for remote signaling or locking mechanisms for tamper-proofing, depending on specific system requirements and availability.

Q10: How does this breaker provide overload protection?

The Siemens 5SY6504-8CC provides overload protection through a thermal tripping mechanism. This mechanism uses a bimetallic strip that heats up due to the current flowing through it.

If the current exceeds the rated value for an extended period, the bimetallic strip bends and triggers the release mechanism, opening the circuit. The tripping time is inversely proportional to the overload current, meaning higher overloads trip faster.

This thermal protection prevents the connected motor and wiring from overheating, which can cause insulation damage and fire hazards over time.