Siemens 5SY6450-7CC Industrial Grade Miniature Circuit Breaker 4P 50A

The Siemens 5SY6450-7CC is a robust, four-pole miniature circuit breaker designed for reliable protection of electrical circuits in industrial environments. Its key advantages include a high breaking capacity of 6kA, ensuring robust protection against short circuits, and a Type C tripping characteristic, suitable for inductive loads that exhibit a temporary inrush current. This 50A rated breaker offers excellent thermal and magnetic trip protection, safeguarding equipment and personnel.

Product Specifications

| Specification             | Value                                     |

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

| Manufacturer              | Siemens                                   |

| Series                    | 5SY6                                      |

| Model Number              | 5SY6450-7CC                               |

| Number of Poles           | 4P                                        |

| Rated Current (Inom)      | 50A                                       |

| Tripping Characteristic   | C                                         |

| Breaking Capacity (Icn)   | 6kA (IEC/EN 60898-1), 10kA (IEC/EN 60947-2) |

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

| Insulation Voltage (Ui)   | 440V AC                                   |

| Frequency                 | 50/60 Hz                                  |

| Mechanical Service Life   | 10,000 operating cycles                   |

| Protection Class          | IP20 (with connected conductors)          |

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

| Mounting Method           | DIN rail                                  |

| Dimensions (W x H x D)    | 72 x 90 x 76 mm                           |

| Conductor Cross-Section   | 0.75 mm² - 35 mm² (solid/stranded)        |

| Tightening Torque         | 2.5 - 3.5 N·m                             |

| Compliance Standards      | IEC/EN 60898-1, IEC/EN 60947-2, UL1077    |

Core Features & Market Positioning

The Siemens 5SY6450-7CC stands out in the industrial circuit protection market due to its adherence to stringent international standards, including IEC/EN 60898-1 and IEC/EN 60947-2. This adherence ensures reliable performance and safety in demanding applications. Its Type C tripping curve is particularly advantageous for applications involving motors, transformers, and fluorescent lighting, where temporary high inrush currents are common, preventing nuisance tripping while still offering robust protection against overloads and short circuits. The four-pole design provides comprehensive protection for three-phase systems, ensuring all live conductors are disconnected simultaneously. This makes the 5SY6450-7CC a preferred choice for integrators and facility managers prioritizing safety, reliability, and compliance in their electrical installations.

Key Application Scenarios

This Siemens 5SY6450-7CC miniature circuit breaker is engineered for a wide array of industrial applications. It is ideally suited for protecting power circuits in manufacturing plants, control cabinets, and distribution boards where consistent and dependable overcurrent protection is paramount. Its 6kA breaking capacity is sufficient for many standard industrial installations, offering protection against faults up to this level. The C-curve characteristic makes it a robust option for circuits feeding inductive loads, such as motor control centers (MCCs), pump systems, and HVAC equipment, which often experience higher startup currents. Its four-pole configuration ensures complete isolation of three-phase circuits, a critical safety requirement in many industrial settings.

Practical System Integration Guidance

Integrating the Siemens 5SY6450-7CC into existing or new electrical systems is straightforward, owing to its standard DIN rail mounting and straightforward termination. The unit accepts solid and stranded conductors ranging from 0.75 mm² to 35 mm², with recommended tightening torques between 2.5 and 3.5 N·m to ensure secure and reliable connections. It's crucial to ensure that the supply voltage and frequency match the breaker's specifications (230/400V AC, 50/60 Hz) to prevent damage and ensure proper operation. For three-phase applications, proper wiring of all four poles is essential for balanced protection and safety. Users can refer to detailed technical data sheets and installation manuals from Siemens for specific wiring diagrams and application notes.

Operation and Risk Mitigation

The Siemens 5SY6450-7CC operates by automatically interrupting the circuit when the current exceeds a safe level, either due to overload or a short circuit. The thermal element responds to overloads, while the magnetic element trips instantaneously for short circuits. Its IP20 protection rating means it's protected against solid objects larger than 12.5mm but requires housing to protect against dust and water ingress. To mitigate risks, always ensure power is isolated before installation or maintenance. Verify correct wiring to prevent phase imbalances or short circuits. Regularly inspect terminals for tightness and signs of overheating. In the unlikely event of a fault, the breaker will trip, indicating a problem that needs investigation rather than being ignored. Always replace a tripped breaker with one of the same type and rating.

Scalability & Long-Term Value

While the Siemens 5SY6450-7CC is a standalone protection device, its value is enhanced by its compatibility within the broader Siemens SENTRON protection product line. This means it can be seamlessly integrated into larger Siemens electrical distribution systems, allowing for unified control and monitoring where advanced solutions are employed. Although this specific model does not feature integrated digital communication for IIoT, its reliable performance and robust design ensure long-term operational value and reduced maintenance needs. Future system upgrades can incorporate smart metering or remote monitoring devices alongside these breakers, leveraging the foundational safety and reliability they provide.

Frequently Asked Questions (FAQs)

Q1: What is the breaking capacity of the Siemens 5SY6450-7CC?

The Siemens 5SY6450-7CC has a rated breaking capacity of 6kA according to IEC/EN 60898-1 standards.

It also boasts a higher breaking capacity of 10kA when tested against IEC/EN 60947-2 standards.

This dual rating ensures versatility and reliability across different application requirements.

Q2: What does the 'C' in 5SY6450-7CC signify?

The 'C' denotes the tripping characteristic of the circuit breaker.

Type C breakers are designed to trip between 5 to 10 times the rated current.

This makes them suitable for circuits with moderate inrush currents, like inductive loads.

Q3: Can the Siemens 5SY6450-7CC be used in residential applications?

While primarily designed for industrial use, its specifications align with some residential applications.

However, it's always best to consult local electrical codes and standards for residential installations.

Strict adherence to regulations ensures safety and compliance.

Q4: What is the maximum conductor size that can be connected?

The 5SY6450-7CC accepts conductor cross-sections up to 35 mm².

This accommodates a wide range of wiring gauges encountered in industrial settings.

Ensure proper termination torque for a secure connection.

Q5: Is this circuit breaker suitable for DC circuits?

The primary rating is for AC circuits (230/400V AC).

It has a DC rated value of up to 60V or a maximum of 72V.

For higher DC voltage applications, specialized DC breakers are required.

Q6: How do I reset a tripped Siemens 5SY6450-7CC breaker?

Ensure the fault has been cleared before attempting to reset.

Toggle the breaker's handle fully to the OFF position, then back to the ON position.

If it trips again immediately, there is an ongoing fault that requires investigation.

Q7: What are the physical dimensions of the 5SY6450-7CC?

The breaker measures 72mm in width and 90mm in height.

Its depth is 76mm, with an installation depth of 70mm for DIN rail mounting.

These dimensions are standard for a 4-pole breaker, fitting typical distribution panels.

Q8: Does the 5SY6450-7CC offer protection against arc faults?

This model does not inherently provide arc fault protection.

Arc fault protection is typically offered by specific devices like AFDDs (Arc Fault Detection Devices).

It's recommended to use arc fault protection where required by electrical codes.

Q9: What is the operating temperature range for this breaker?

The Siemens 5SY6450-7CC is designed for operation in ambient temperatures from -25°C to +55°C.

Maintaining this temperature range ensures reliable performance and longevity.

Higher temperatures can affect the breaker's current-carrying capacity.

Q10: What is the warranty period for this Siemens circuit breaker?

Several vendors offer a 1-year warranty on new Siemens 5SY6450-7CC breakers.

Some also provide a 30-day return policy for defective items.

Always check the specific warranty terms from your supplier.