BS EN 61439: Low-voltage switchgear and controlgear assemblies.

BS EN 61439 is a British standard that specifies the requirements for the design, construction, testing, and performance of low-voltage switchgear and controlgear assemblies (often referred to as LV switchboards). It is part of the EN 61439 series of standards, which harmonize the requirements for these assemblies within Europe.

Here are some key details about BS EN 61439:

Scope:

BS EN 61439 defines the specifications for low-voltage switchgear and controlgear assemblies used in electrical installations. These assemblies are designed to protect, control, and disconnect electrical circuits, providing an interface between electrical power sources and loads in commercial, industrial, and residential buildings.

Structure of the Standard:

The standard consists of several parts, each focusing on different aspects of low-voltage switchgear and controlgear assemblies. Key parts include:

1. BS EN 61439-1 – General Rules:
   • This part covers general requirements, including definitions, ratings, design, construction, testing, and performance aspects.
   • Specifies criteria for electrical, mechanical, and thermal performance.
   • Includes assembly classifications, testing conditions, and verification methods.
2. BS EN 61439-2 – Power Switchgear and Controlgear Assemblies:
   • Specifies requirements for assemblies used in power distribution.
   • Focuses on safety and operational characteristics for handling high power levels in industrial environments.
3. BS EN 61439-3 – Distribution Boards Intended to be Operated by Ordinary Persons (DBO):
   • Focuses on distribution boards that can be operated by non-electrically skilled persons, such as those in residential or small commercial settings.
4. BS EN 61439-4 – Assemblies for Construction Sites:
   • Specifies requirements for temporary switchgear used at construction sites, where conditions might vary.
5. BS EN 61439-5 – Assemblies for Specific Applications:
   • Addresses specific applications such as assemblies for high-rise buildings, data centers, or mining operations.

Key Requirements:

1. Design and Construction:
   • Assemblies must be designed for ease of operation and to meet safety standards.
   • The construction must allow for easy installation and maintenance, with clear identification and separation of conductors.
   • They must also meet specific ingress protection (IP) levels to prevent dust or water ingress, depending on the location and application.
2. Electrical and Mechanical Testing:
   • The assemblies must undergo extensive testing, including:
     • Dielectric properties: Testing insulation strength.
     • Temperature rise: Ensuring they can handle thermal stress under normal conditions.
     • Short-circuit withstand strength: Ensuring the assembly can withstand short circuits without failure.
     • Mechanical endurance: Ensuring the assembly maintains structural integrity under mechanical stress.
3. Safety Features:
   • The standard emphasizes safe design to protect operators from electrical shock, fires, and other hazards. These include:
     • Properly rated components to prevent overload.
     • Earthing requirements to prevent electric shock.
     • Clear labeling of components and terminal points to ensure safe installation and maintenance.
4. Modularity:
   • Assemblies are designed to be modular, allowing easy configuration for different applications and sizes. This modularity helps in scaling the assembly to meet specific needs.
5. Environmental Considerations:
   • Some versions of the standard also address environmental considerations, such as the protection against corrosive environments and the potential for exposure to extreme temperatures.

Compliance and Certification:

• For a switchgear assembly to be compliant with BS EN 61439, manufacturers must have their products tested and certified by accredited bodies.
• The standard also provides guidelines for the documentation required to prove compliance, such as technical files, test reports, and declarations of conformity.

Applications:

• Industrial power distribution systems.
• Commercial and residential electrical installations.
• Renewable energy systems, especially for connecting solar and wind systems to the grid.
• Data centers and critical infrastructure.

In short, BS EN 61439 is essential for ensuring the safety, reliability, and performance of low-voltage switchgear and controlgear assemblies in various electrical installations.