Siemens 5SU1656-1KK25 RCCB Earth Leakage Protection Switch 25A 300mA 1P+N C

The Siemens 5SU1656-1KK25 RCCB is a robust Residual Current Circuit Breaker (RCCB) designed for essential earth leakage protection in various electrical installations. This 25A, 300mA, 1-pole + neutral device with a Type C tripping characteristic offers superior safety and reliability. Its key advantages include rapid detection and interruption of fault currents, preventing potential electric shocks and fire hazards. The core features of the 5SU1656-1KK25 RCCB include its compact design for efficient panel space utilization, high breaking capacity for industrial applications, and compliance with international safety standards. Essential technical parameters include a rated voltage of 230/400V AC, a rated frequency of 50/60 Hz, and an operating temperature range of -25°C to +45°C.

Product Specifications

| Feature               | Specification                               |

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

| Product Type          | Residual Current Circuit Breaker (RCCB)     |

| Manufacturer          | Siemens                                     |

| Model Number          | 5SU1656-1KK25                               |

| Rated Current (In)    | 25A                                         |

| Rated Residual Current| 300mA                                       |

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

| Tripping Characteristic | Type C                                      |

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

| Rated Frequency       | 50/60 Hz                                    |

| Breaking Capacity (Icn)| 6kA                                         |

| Mounting Type         | DIN Rail                                    |

| Environmental Class   | IP20                                        |

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

Core Features & Market Positioning

The Siemens 5SU1656-1KK25 RCCB distinguishes itself through its advanced residual current detection technology, ensuring prompt tripping even with small leakage currents, thus significantly enhancing personnel safety. Its Type C tripping characteristic is specifically engineered to handle inrush currents common in industrial settings, preventing nuisance tripping while maintaining effective protection. This positions the 5SU1656-1KK25 RCCB as a reliable choice for demanding environments where uninterrupted operation alongside stringent safety is paramount. Siemens' reputation for quality and durability further solidifies its market standing, offering users confidence in long-term performance and compliance with electrical safety regulations.

Key Application Scenarios

This Siemens RCCB is ideally suited for main distribution boards and sub-distribution boards in commercial buildings, industrial facilities, and workshops. Its 300mA sensitivity makes it effective for fire protection purposes, safeguarding against insulation faults that could lead to electrical fires. Common applications include protecting circuits supplying machinery, lighting systems, and power outlets in areas where the risk of earth faults is elevated due to the presence of conductive materials or complex equipment. It is a critical component for ensuring compliance with electrical installation standards that mandate earth leakage protection.

Practical System Integration Guidance

Integrating the Siemens 5SU1656-1KK25 RCCB into existing electrical systems is straightforward due to its standard DIN rail mounting and clear terminal markings. Proper wiring involves connecting the incoming live and neutral conductors to the designated input terminals and routing the outgoing protected live and neutral conductors to the downstream circuits. Ensuring correct polarity is crucial for the device to function as intended. The device is designed for single-phase with neutral configurations, and it is imperative that both live and neutral conductors pass through the RCCB for effective earth leakage detection.

Operation and Risk Mitigation

The primary function of the 5SU1656-1KK25 RCCB is to detect imbalances in current between the live and neutral conductors, indicative of current flowing to earth through an unintended path. Upon detecting such a leakage exceeding its 300mA threshold, it rapidly disconnects the circuit, minimizing the duration of potentially hazardous current flow. To mitigate risks, regular testing of the RCCB using its integrated test button is recommended to ensure its operational readiness. Proper electrical load management and ensuring the integrity of wiring insulation are essential complementary measures for comprehensive electrical safety.

Scalability & Long-Term Value

The Siemens 5SU1656-1KK25 RCCB is designed for seamless integration within Siemens' broader electrical distribution portfolio, ensuring compatibility with their circuit breakers and switchgear components. While RCCBs are primarily protection devices, their value is enhanced through their contribution to overall system reliability and compliance, reducing the likelihood of costly downtime and damage. As electrical systems evolve towards smart grids and IIoT integration, the fundamental need for reliable earth leakage protection remains, making robust devices like the 5SU1656-1KK25 a long-term asset for any installation.

Frequently Asked Questions (FAQs)

What is the primary function of the Siemens 5SU1656-1KK25 RCCB?

The Siemens 5SU1656-1KK25 RCCB is primarily designed for earth leakage protection. It detects imbalances between live and neutral currents. This prevents electric shocks and fires caused by insulation faults.

It operates by monitoring the current flowing in and out of a circuit. If more current flows out than returns, it indicates a leakage. The device then rapidly interrupts the power supply.

This crucial safety function is vital in all types of electrical installations. It ensures the protection of both people and property from electrical hazards.

What does 25A and 300mA signify for this RCCB?

The 25A rating refers to the maximum continuous current the RCCB can safely handle. This is the operational current capacity for the protected circuit. Exceeding this can lead to overheating and damage.

The 300mA signifies the residual current sensitivity. This is the leakage current level that triggers the RCCB to trip. It's a higher sensitivity for fire protection.

For personal protection, lower mA ratings are typically used. The 300mA rating is suitable for preventing fires from insulation faults.

Is the Siemens 5SU1656-1KK25 suitable for residential use?

While technically capable, the 300mA sensitivity is generally for fire protection. Residential settings typically use 30mA RCCBs for direct personal protection.

This 300mA device is more commonly specified for industrial or commercial applications. It's used where preventing electrical fires is the primary concern. Always consult local electrical codes and standards.

For most home installations, a lower sensitivity RCCB or RCD would be recommended for socket outlets. This ensures compliance with safety regulations for shock prevention.

What is a Type C tripping characteristic, and why is it important?

A Type C tripping characteristic indicates the RCCB's response to overcurrents. It is designed to tolerate higher inrush currents than Type B or Type A. This is common in industrial settings.

This characteristic prevents nuisance tripping when inductive loads like motors start up. The RCCB will still trip for earth leakage faults. It balances protection with operational reliability.

For circuits with significant motor loads or transformers, a Type C is often specified. This ensures the circuit breaker doesn't trip unnecessarily during normal operation.

How do I install the Siemens 5SU1656-1KK25 RCCB?

Installation requires mounting the RCCB onto a standard DIN rail within an electrical enclosure. Ensure the power to the circuit is completely isolated before starting.

Connect the incoming live and neutral wires to the designated input terminals. Then, connect the outgoing protected live and neutral wires to the output terminals for the downstream circuit.

It is imperative to ensure correct polarity and that both live and neutral conductors pass through the device for proper function. Always follow local electrical codes and manufacturer instructions.

Can this RCCB be used for both single-phase and three-phase circuits?

The Siemens 5SU1656-1KK25 is a 1-pole + Neutral (1P+N) device. This means it is designed for single-phase circuits that require neutral conductor switching. It cannot be used for three-phase applications directly.

For three-phase circuits, a 4-pole RCCB would be necessary. These devices are designed to simultaneously switch all three live conductors and the neutral. Ensure correct pole configuration for your system.

Always verify the voltage and current requirements of your circuit against the RCCB's specifications. Using the incorrect type can lead to malfunction or safety hazards.

What is the breaking capacity (kA) of this RCCB?

The breaking capacity of the Siemens 5SU1656-1KK25 RCCB is 6kA. This refers to the maximum fault current it can safely interrupt without being destroyed. It indicates the level of short-circuit current it can handle.

A 6kA breaking capacity is generally suitable for most residential and commercial distribution boards. It ensures the device can safely disconnect the circuit during a significant short circuit.

This specification is crucial for ensuring the safety of the entire electrical installation. It must be coordinated with the upstream overcurrent protection devices.

How often should I test the Siemens 5SU1656-1KK25 RCCB?

It is recommended to test the functionality of the RCCB regularly. A common recommendation is to perform tests monthly or at least every six months. This ensures the tripping mechanism is operational.

Most RCCBs, including this model, have a built-in test button. Pressing this button simulates an earth leakage fault and should cause the RCCB to trip. If it doesn't trip, it may need replacement.

Regular testing is a critical part of maintaining electrical safety. It confirms that the device will perform its protective function when needed.

What safety standards does the Siemens 5SU1656-1KK25 comply with?

The Siemens 5SU1656-1KK25 RCCB complies with key international and regional safety standards for electrical devices. These typically include IEC/EN 61009 standards, which govern residual current-operated circuit-breakers with integral overcurrent protection.

Compliance with these standards ensures the product has undergone rigorous testing for safety and performance. It guarantees that the device meets established benchmarks for electrical protection and reliability.

Adhering to these standards is essential for electrical installations to meet regulatory requirements. It provides assurance that the device will function as intended and safely.

Where can I find the datasheet or manual for this specific RCCB?

You can typically find the datasheet or user manual for the Siemens 5SU1656-1KK25 RCCB on the official Siemens Industry website. Siemens provides extensive documentation for their products.

Search for the product model number "5SU1656-1KK25" on their support or product pages. You can usually download the PDF documents directly from their portal.

Alternatively, authorized Siemens distributors or electrical wholesalers may also provide access to product documentation upon request. Consulting these resources ensures correct installation and usage.