What is Surge Protection? The Invisible Shield for Electrical Installations

In our modern world, where electrical devices are integral to every aspect of life, understanding surge protection is vital.

Surge Protection Devices (SPDs) are unsung heroes, safeguarding our electrical systems from unexpected surges of energy that can cause damage or even catastrophic failure.

Let’s delve into the world of surge protection, its types, requirements in wiring regulations, and its criticality, especially in buildings with lightning protection.

An Introduction What is Surge Protection

Understanding Surge Protection Devices (SPDs)

Surge protection devices are specialized components installed in electrical systems to protect against transient overvoltages or surges.

These surges can originate from various sources, such as lightning strikes, power grid issues, or even the switching of large electrical loads within a building.

Without SPDs, these sudden spikes in voltage can damage electronic equipment, cause data loss, or even pose fire hazards.

The Three Types of Surge Protection

To effectively guard against these electrical surges, SPDs are categorized into three primary types, each serving a distinct purpose and installed at different points in the electrical infrastructure:

  1. Type 1 Surge Protectors: Designed to handle the high energy associated with direct lightning strikes or major external surges, Type 1 SPDs are installed at the service entrance of a building. They are the first line of defence and are typically integrated with external lightning protection systems.
  2. Type 2 Surge Protectors: These are installed downstream of Type 1 protectors, typically at distribution boards. They offer protection against indirect lightning surges and other external source surges that may penetrate into the building. Type 2 SPDs handle lower surge currents than Type 1 and are crucial for protecting the internal electrical system.
  3. Type 3 Surge Protectors: Installed close to sensitive electronic equipment, Type 3 SPDs provide fine protection against residual surges. They are the last line of defence, safeguarding individual devices from surges that might bypass Type 1 and Type 2 protectors.

Placement of SPDs in Installations

The effectiveness of surge protection hinges on strategic placement:

  • Type 1 Protectors are installed where the main power supply enters the building, generally in the main distribution board.
  • Type 2 Protectors are fitted in sub-distribution boards or specific circuits needing added protection.
  • Type 3 Protectors are placed as close as possible to the equipment they protect, often at socket outlets.

Surge Protection in BS 7671 and Wiring Regulations

The UK’s BS 7671 Wiring Regulations underscore the importance of surge protection in electrical installations.

These regulations mandate the assessment of surge protection needs for any installation, emphasizing their installation in buildings at greater risk, such as those with lightning protection systems or locations prone to electrical storms.

Compliance with BS 7671 ensures that electrical installations are not just operational but safe and resilient against transient overvoltages.

The Necessity of Surge Protection in Lightning-Protected Buildings

In buildings with lightning protection systems, integrating surge protection is non-negotiable.

Lightning strikes, even when intercepted by lightning protection systems, can induce secondary surges in electrical systems.

SPDs ensure these induced surges are managed effectively, protecting the internal electrical infrastructure and sensitive equipment.

Regular Inspection and Maintenance

Like any critical safety system, surge protection systems require regular inspection and maintenance.

Over time, SPDs can degrade, especially after intercepting significant surges.

Regular checks ensure they are functional and effective.

This maintenance includes checking indicators (many SPDs have visual indicators for operational status), verifying connections, and ensuring they are not damaged or degraded.

Single-Use SPDs vs. Resettable SPDs

Not all SPDs are created equal. Single-use SPDs, once they intercept a significant surge, must be replaced as they cannot function again.

Resettable SPDs, however, can continue to provide protection after intercepting surges, although their capacity may diminish over time.

The choice between single-use and resettable SPDs depends on the specific needs and risk assessment of the installation.

Manufacturers of SPDs in the UK

Several reputable manufacturers supply SPDs in the UK market, each offering a range of products to suit various needs. Notable names include:

  • Schneider Electric: Known for their comprehensive range of electrical components, including high-quality SPDs.
  • Eaton: Offers a wide array of surge protection solutions, known for reliability and effectiveness.
  • ABB: A global leader in electrical products, ABB’s SPDs are synonymous with quality and durability.

Conclusion – What is surge protection?

Surge protection is an essential aspect of modern electrical installations, acting as a safeguard against the unpredictable and often destructive nature of electrical surges.

Whether it’s protecting a home’s electronics or an industrial facility’s critical infrastructure, SPDs play a crucial role.

Their importance is amplified in buildings with lightning protection, where the risk of surge-induced damage is significantly higher.

Adhering to BS7671 regulations, ensuring proper placement, and regular maintenance of these devices are key to maintaining