Siemens 5SU9326-1CN50 Earth Leakage Protection Module 50A 30mA 2P C

The Siemens 5SU9326-1CN50 is a vital component for ensuring electrical safety in diverse industrial and commercial settings. This 2-pole, 50A, 30mA Earth Leakage Protection Module (ELPD) is engineered to provide rapid detection and interruption of fault currents to earth, safeguarding personnel and equipment from dangerous electrical shocks and fire hazards. Its C-curve tripping characteristic ensures it is suitable for applications with moderate inrush currents. Designed for reliability and ease of integration, the 5SU9326-1CN50 offers robust protection, making it an indispensable part of modern electrical installations.

Product Specifications

| Feature              | Specification                               |

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

| Product Type         | Earth Leakage Protection Module (ELPD)      |

| Manufacturer         | Siemens                                     |

| Model Number         | 5SU9326-1CN50                               |

| Poles                | 2                                           |

| Rated Current (In)   | 50A                                         |

| Rated Residual Current | 30mA                                        |

| Tripping Characteristic | C                                           |

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

| Frequency            | 50/60 Hz                                    |

| Breaking Capacity (Icn)| 6kA                                         |

| Mounting Type        | DIN Rail                                    |

| IP Protection Rating | IP20 (device), IP40 (enclosure)             |

| Operating Temperature| -25°C to +55°C                              |

Core Features & Market Positioning

The Siemens 5SU9326-1CN50 distinguishes itself through its superior construction quality and adherence to stringent international safety standards. Its precision tripping mechanism at 30mA offers sensitive detection of earth faults, minimizing the risk of electric shock, which is a critical differentiator in safety-critical applications. The C-curve characteristic provides a balance, allowing for reliable operation in circuits with moderate inductive or capacitive loads, such as those found in motor control or lighting systems, without nuisance tripping. This makes it a preferred choice over simpler Residual Current Devices (RCDs) where a degree of controlled inrush current handling is necessary, positioning it as a premium solution for demanding installations.

Key Application Scenarios

This ELPD finds extensive use across various sectors requiring high levels of electrical safety. It is particularly crucial in commercial buildings, manufacturing plants, and workshops to protect personnel from ground faults, especially in areas with increased risk of contact with conductive materials. Applications include safeguarding power circuits for machinery, distribution boards, and sensitive electronic equipment that could be damaged by leakage currents. Furthermore, its 50A rating makes it suitable for main incomer protection or branch circuits with significant load demands, ensuring compliance with electrical codes and safety regulations.

Practical System Integration Guidance

Integrating the Siemens 5SU9326-1CN50 into an electrical system is a straightforward process, typically involving mounting it onto a standard 35mm DIN rail within a distribution board or enclosure. The module connects via screw terminals, requiring proper torque settings for secure connections to prevent overheating. Live and Neutral conductors are connected to the designated input terminals, and the output terminals supply the protected circuit. It's essential to ensure that the incoming supply conductors are correctly phased and sized according to the 50A rating. For optimal performance and safety, it should be installed downstream of the main overcurrent protection device.

Operation and Risk Mitigation

The 5SU9326-1CN50 operates by continuously monitoring the balance of current flowing between the live and neutral conductors. If an imbalance, indicative of current leaking to earth, exceeds the 30mA threshold, the module rapidly disconnects the circuit. This swift action is key to preventing electric shock and fires. Risk mitigation is inherent in its design; however, regular testing via the integrated test button is recommended to ensure the tripping mechanism remains functional. It's important to note that this device protects against earth leakage but does not provide overcurrent or short-circuit protection; these functions must be handled by a separate circuit breaker or fuse upstream.

Scalability & Long-Term Value

The Siemens 5SU9326-1CN50 is designed for seamless integration within Siemens' broader range of industrial electrical components, offering excellent compatibility with other SIRIUS or ALPHA series devices. Its modular design allows for easy replacement or addition to existing distribution systems. While not directly a digital IIoT component, its reliable protection underpins the stability of connected systems, contributing to the overall operational integrity required for smart factory or building management integration. Its robust build quality ensures a long service life, providing consistent protection and reducing the total cost of ownership over time.

Frequently Asked Questions

What is the primary function of the Siemens 5SU9326-1CN50?

This module provides essential protection against earth leakage currents. It rapidly disconnects power if a fault path to ground is detected. This action prevents electric shocks and potential fires.

It is designed to sense even small imbalances in current. Such imbalances indicate a dangerous leakage to earth. Its 30mA sensitivity is crucial for personnel safety.

The 5SU9326-1CN50 acts as a safety device. It complements overcurrent protection by specifically addressing ground fault scenarios.

How does the 30mA rating impact its application?

A 30mA residual current is the standard for shock protection. It's sensitive enough to prevent severe injury. This rating is vital for residential and commercial safety.

This sensitivity ensures rapid disconnection. It minimizes the duration of current flow through the human body. It meets critical safety regulations worldwide.

For industrial settings, it guards against faults from damaged insulation or accidental contact. This protects both people and valuable equipment.

What does the "C" in 5SU9326-1CN50 signify?

The "C" denotes its tripping characteristic. It means the module can tolerate higher inrush currents. This is common with inductive loads like motors.

This characteristic prevents nuisance tripping. It occurs when starting motors or switching lighting. The C-curve offers reliable operation in such scenarios.

It balances sensitivity with immunity to transient overcurrents. This makes it versatile for various industrial branch circuits.

Can this module replace a standard circuit breaker?

No, this module is not a direct replacement for a circuit breaker. It specifically protects against earth leakage. It does not offer overcurrent or short-circuit protection.

A circuit breaker protects against overloads and short circuits. These are different fault conditions than earth leakage. Both devices are often required for complete protection.

For full safety, it should be installed alongside an appropriate circuit breaker. The breaker typically handles overcurrents, while this module handles ground faults.

What is the breaking capacity of this ELPD?

The breaking capacity (Icn) is 6kA. This indicates the maximum fault current it can safely interrupt. It ensures the module itself doesn't fail during a severe fault.

This 6kA rating is suitable for many standard distribution systems. It aligns with typical fault levels found in commercial and light industrial applications.

Always ensure the system's prospective fault current does not exceed this rating. Consult with an electrician if unsure about your installation's fault levels.

Is the Siemens 5SU9326-1CN50 suitable for outdoor use?

The device itself has an IP20 rating. This means it is protected against solid objects over 12.5mm. It is not designed for direct exposure to the elements.

For outdoor installations, it must be housed in a suitable enclosure. This enclosure needs an appropriate IP rating to protect against dust and water ingress.

The operating temperature range is -25°C to +55°C. Ensure the enclosure provides adequate ventilation to maintain this range in extreme weather.

What type of loads can be connected to the 50A rating?

The 50A rating indicates the maximum continuous current the module can handle. It's suitable for circuits with significant power demands. Examples include main distribution feeders or circuits powering multiple machines.

Carefully calculate the total load of connected equipment. Ensure the sum of operating currents does not exceed 50A under normal conditions. Allow for a safety margin.

Remember that this rating is for the module's operational current capacity. Overcurrent protection must still be provided by a separate upstream device.

How do I test the functionality of the 5SU9326-1CN50?

Most ELPDs, including this Siemens model, have a built-in test button. Pressing this button simulates an earth fault. It should immediately trip and disconnect the circuit.

Regular testing is crucial for maintaining safety. It ensures the internal trip mechanism and relay are functional. It is recommended to test monthly.

If the module fails to trip during a test, it must be replaced immediately. This indicates a malfunction and compromised safety. Consult a qualified electrician for inspection.

What is the difference between this module and a standard RCD?

This module is a type of Residual Current Device (RCD). However, it's often termed an Earth Leakage Protection Module (ELPD) in industrial contexts. The core function of detecting earth faults is the same.

The "C" characteristic in its designation is a key differentiator. It provides enhanced immunity to transient overcurrents compared to basic RCDs. This reduces nuisance tripping.

Siemens often uses specific product lines like the 5SU series for enhanced performance and integration within their industrial control systems.

Can this module be used in a TT or TN earthing system?

Yes, the 5SU9326-1CN50 is designed for use in various earthing systems, including TT and TN. Its function is to detect leakage current regardless of the specific earthing arrangement.

In a TT system, the earth electrode at the installation is separate from the utility's earth. The ELPD is crucial here for protection. In a TN system, fault current returns via the neutral conductor.

Proper selection and coordination with other protective devices are essential for optimal performance in any earthing system. Always follow local wiring regulations.