Siemens 5SU9156-7KK40 High Current Earth Leakage Protector RCCB 40A 10mA 1P+N C

The Siemens 5SU9156-7KK40 is a high-performance Residual Current Circuit Breaker with Overcurrent protection (RCBO) designed for robust electrical safety in demanding applications. This 1-pole + neutral (1P+N) device offers advanced protection against earth leakage, overcurrents, and short circuits, ensuring the integrity of both electrical systems and personnel safety. Its key advantages include a high current rating of 40A, a sensitive 10mA earth leakage detection capability, and a reliable C-type tripping characteristic. The compact, 2-module width design facilitates easy integration into standard electrical enclosures, making it a practical choice for modern installations.

Product Specifications

| Parameter                  | Value                                         | Parameter                       | Value                                         |

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

| Product Model          | 5SU9156-7KK40                                 | Manufacturer                | Siemens                                       |

| Rated Current (In)     | 40A                                           | Number of Poles             | 1P+N                                          |

| Residual Current (I∆n) | 10mA                                          | Tripping Characteristic     | C                                             |

| Breaking Capacity (Icn)| 6kA (acc. to IEC60898-1)                      | Rated Voltage (Un)          | 230/240V AC                                   |

| Type                   | A (for AC and pulsating DC residual currents) | Modular Width               | 2 MW (36mm)                                   |

| Energy Limitation Class| 3                                             | Operating Temperature       | -25°C to +45°C                                |

| Mechanical Life Cycle  | > 20,000 switching cycles                     | Protection Degree           | IP20 (installed), IP40 (in distribution box)  |

| Standards Compliance   | IEC 60947-2, EN 60898, IEC 61009/GB 16917      | Mounting Type               | DIN rail (35mm)                               |

| Surge Current Withstand| 8/10 µs                                       | Touch Protection            | Yes                                           |

| Material               | Halogen-free                                  | Country of Origin           | China (typical), Romania (also found)         |

Core Features & Market Positioning

The Siemens 5SU9156-7KK40 stands out in the market due to its advanced electronic tripping mechanism, ensuring swift and reliable detection of earth leakage faults. Its Type A classification is a significant advantage, as it offers protection against both sinusoidal AC and pulsating DC residual currents, a broader scope than Type AC devices. This positions the 5SU9156-7KK40 as a superior choice for applications where diverse fault current types are anticipated. The device's robust 40A current rating, coupled with a 6kA breaking capacity, makes it suitable for higher load circuits, differentiating it from lower-rated competitors. Its inclusion in Siemens' SENTRON range signifies a commitment to quality, reliability, and safety, aligning with industry expectations for premium electrical protection components.

Key Application Scenarios

This Siemens RCBO is ideally suited for a wide array of applications demanding comprehensive electrical safety. It is a critical component in residential installations, particularly for circuits supplying kitchens, bathrooms, garages, and outdoor areas where the risk of electric shock is heightened. In commercial settings, the 5SU9156-7KK40 provides essential protection for office spaces, retail environments, and workshops. For industrial applications, it can be employed in control panels and distribution boards to safeguard machinery and protect personnel from electrical hazards. Its 10mA sensitivity is particularly effective for personal protection against direct contact, while its overall design ensures compliance with stringent safety regulations across various sectors.

Practical System Integration Guidance

Integrating the Siemens 5SU9156-7KK40 into existing or new electrical systems is straightforward due to its standard 35mm DIN rail mounting and compact 2-module width. Installation involves ensuring the main power supply is disconnected and locked out. The conductors (solid or stranded, up to 35mm²) are stripped to the appropriate length (approx. 6-7mm) and securely connected to the designated terminals. It's crucial to ensure proper torque is applied to the terminal screws as per manufacturer recommendations to guarantee a reliable connection and prevent overheating. The device's clear status indicator simplifies post-installation checks and ongoing monitoring.

Operation and Risk Mitigation

The Siemens 5SU9156-7KK40 operates by continuously monitoring the current flowing through the live and neutral conductors. If an imbalance occurs, indicating a current leakage to earth, the device will rapidly trip and disconnect the circuit. The "C" tripping characteristic means it is designed to handle inrush currents from inductive loads without nuisance tripping, while still providing sensitive protection against short circuits. In the event of a fault, the clearly visible status indicator on the device will signal the tripped state. Troubleshooting typically involves verifying power supply, checking for loose connections, and testing the device's functionality using its integrated test button. If the device trips repeatedly without an apparent fault, further investigation of the circuit load and wiring integrity is recommended.

Scalability & Long-Term Value

As part of Siemens' extensive SENTRON product line, the 5SU9156-7KK40 offers excellent compatibility with other Siemens components and systems, facilitating seamless integration and future upgrades. This compatibility ensures that electrical installations can be scaled to meet evolving demands without compromising protection or performance. While the 5SU9156-7KK40 itself is a standalone protective device, its integration into broader Siemens automation and control platforms, such as those found in the Siemens Industry Mall, provides pathways for advanced monitoring and management in industrial environments. This future-proofing aspect, combined with Siemens' reputation for durable and reliable products, underscores the long-term value of investing in the 5SU9156-7KK40.

Frequently Asked Questions (FAQs)

Q1: What is the primary function of the Siemens 5SU9156-7KK40?

The Siemens 5SU9156-7KK40 is an RCBO, integrating Residual Current Circuit Breaker (RCCB) and Miniature Circuit Breaker (MCB) functions. It protects against earth leakage, overload, and short circuits. This dual protection ensures comprehensive safety for personnel and electrical equipment.

This device is crucial for preventing electric shock by quickly interrupting circuits with dangerous current imbalances. Its sensitive 10mA trip rating is ideal for direct contact protection in residential and sensitive areas.

The RCBO also safeguards electrical systems from damage caused by overcurrents and short circuits, thus preventing fires and equipment failures. It ensures operational continuity while maintaining high safety standards.

Q2: What type of residual current does the Siemens 5SU9156-7KK40 detect?

The Siemens 5SU9156-7KK40 is a Type A RCBO. This means it can detect both sinusoidal AC residual currents and pulsating DC residual currents. This is a key advantage over Type AC devices, which only detect AC.

This enhanced detection capability makes the 5SU9156-7KK40 suitable for a wider range of applications. It is particularly important in modern installations with electronic equipment that can generate non-sinusoidal leakage currents.

By detecting these more complex fault currents, Type A devices offer superior protection against electric shock in diverse electrical environments. This makes them a preferred choice for critical safety applications.

Q3: Can the Siemens 5SU9156-7KK40 be used in high-current applications?

Yes, the Siemens 5SU9156-7KK40 features a robust rated current of 40A. This allows it to be used in circuits with significant electrical loads. Its 6kA breaking capacity also ensures it can safely interrupt fault currents up to this level.

This high current rating, combined with its sensitive earth leakage protection, makes it versatile. It is suitable for circuits that might experience inrush currents typical of motor loads or other inductive equipment.

The device is designed to provide reliable protection even under demanding conditions, making it a solid choice for many residential, commercial, and light industrial applications requiring substantial current handling.

Q4: What standards does the Siemens 5SU9156-7KK40 comply with?

The Siemens 5SU9156-7KK40 adheres to several key international and national standards. It is compliant with IEC 60947-2 and EN 60898, which are fundamental for circuit breaker performance and safety.

Additionally, it meets the requirements of IEC 61009/GB 16917, specifically pertaining to Residual Current Circuit-Breakers with Overcurrent protection (RCBOs). This ensures its suitability for combined protection applications.

Compliance with these standards guarantees that the device has undergone rigorous testing for electrical safety, performance, and reliability, assuring users of its quality and operational integrity.

Q5: What is the physical size and installation method for this RCBO?

The Siemens 5SU9156-7KK40 has a compact design, occupying two modular widths (36mm). This space-saving form factor allows for efficient use of space within electrical distribution boards and panels.

It is designed for easy installation onto a standard 35mm DIN rail. This mounting method is widely adopted in electrical installations, ensuring broad compatibility with most switchgear and enclosures.

The device also features touch protection, enhancing safety during installation and maintenance. Its dimensions are approximately 90 mm (height) x 36 mm (width) x 77 mm (depth), facilitating its integration.

Q6: How does the "C" tripping characteristic affect its performance?

The "C" tripping characteristic indicates that the Siemens 5SU9156-7KK40 is designed to handle moderate inrush currents associated with inductive loads. This prevents nuisance tripping in applications like motor start-ups.

However, it still provides rapid disconnection for short-circuit faults. The C-curve strikes a balance between sensitivity for fault protection and tolerance for temporary current surges.

This characteristic makes it suitable for a broad range of general-purpose applications in residential and commercial installations where inductive loads are common.

Q7: Where is a 10mA residual current sensitivity typically recommended?

A residual current sensitivity of 10mA, as found in the 5SU9156-7KK40, is primarily recommended for personnel protection against direct contact. This sensitivity ensures extremely rapid disconnection upon detecting even small current leakages.

It is particularly crucial for circuits in areas with increased risk of electric shock, such as bathrooms, kitchens, and outdoor installations. Here, it provides an enhanced safety layer for users.

While 30mA is the standard for general protection, 10mA offers superior safety where direct contact is a significant concern, fulfilling specific safety regulations for high-risk environments.

Q8: What is the meaning of "1P+N" on the Siemens 5SU9156-7KK40?

"1P+N" signifies that the Siemens 5SU9156-7KK40 is a single-pole device that also includes a neutral pole connection. This means it switches both the live (phase) conductor and the neutral conductor simultaneously.

This configuration is common in single-phase electrical systems, particularly in regions where neutral conductors are switched for enhanced safety. It ensures complete isolation of the circuit when the device trips.

By switching both poles, it provides a higher level of disconnection compared to single-pole devices that only switch the live conductor, offering greater protection against electrical hazards.

Q9: Can this RCBO be used for fire protection?

Yes, the Siemens 5SU9156-7KK40 contributes to fire protection. Residual current devices with sensitivities of 10mA and 30mA are recommended for fire prevention in areas prone to insulation faults.

Persistent low-level earth leakage currents, if not interrupted, can cause overheating and potentially ignite surrounding materials. The 10mA sensitivity of this RCBO helps to mitigate this risk.

By rapidly disconnecting circuits with leakage currents, it reduces the likelihood of sustained arcing or resistive heating, thereby minimizing the risk of electrical fires.

Q10: What is the mechanical life cycle of the Siemens 5SU9156-7KK40?

The Siemens 5SU9156-7KK40 is rated for a mechanical life cycle of over 20,000 switching cycles. This indicates a robust construction designed for long-term durability and frequent operation.

This considerable mechanical lifespan ensures reliable performance over an extended period. It means the device can withstand numerous operations without significant degradation of its internal mechanisms.

This longevity contributes to the overall value proposition of the product, reducing the need for premature replacements and ensuring consistent protection throughout its operational life.