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SPD Surge Protection Devices

Showing 101–109 of 109 results

Niglon SP23S-1PN 40kA Type 2 Surge Protection Device

Niglon SP23S-1PN 40kA Type 2 Surge Protection Device

Delivery usually within 1-3 working days*
SKU: SP23S-1PN
£41.91
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Niglon SP23S-1PN 40kA Type 2 Surge Protection Device

Niglon SP23S-1PN/C40KA 40kA Type 2 Surge Protection Device

Delivery usually within 1-3 working days*
SKU: SP23S-1PN/C40KA
£31.10
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Niglon SP23S-3PN/40KA 40kA Type 2 Surge Protection Device

Niglon SP23S-3PN/40KA 40kA Type 2 Surge Protection Device

Delivery usually within 1-3 working days*
SKU: SP23S-3PN/40KA
£83.24
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Niglon SP23S-3PN/C40KA 40kA Type 2 Surge Protection Device

Niglon SP23S-3PN/C40KA 40kA Type 2 Surge Protection Device

Delivery usually within 1-3 working days*
SKU: SP23S-3PN/C40KA
£79.78
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Niglon SAE2M-23-215 Type 2 (or 3) Surge Protection Device

Niglon SAE2M-23-215 Type 2 (or 3) Surge Protection Device

Delivery usually within 1-3 working days*
SKU: SAE2M-23-215
£40.43
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Niglon SAE3-23-215 Type 2 (or 3) Surge Protection Device

Niglon SAE3-23-215 Type 2 (or 3) Surge Protection Device

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SKU: SAE3-23-215
£40.43
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Niglon SAE5-23-415 Type 2 Surge Protection Device

Niglon SAE5-23-415 Type 2 Surge Protection Device

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SKU: SAE5-23-415
£97.93
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Niglon SAE6M-23-415 Type 2 (or 3) Surge Protection Device

Niglon SAE6M-23-415 Type 2 (or 3) Surge Protection Device

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SKU: SAE6M-23-415
£102.66
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FuseBox SF0100T2 100A Fused Switch with T2 SPD

FuseBox SF0100T2 100A Fused Switch with T2 SPD

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SKU: SF0100T2
£89.70
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Showing 101–109 of 109 results

Surge Protection Devices (SPDs) – Essential Protection for Electrical Systems

A Surge Protection Device (SPD) protects electrical systems from transient overvoltages, commonly known as power surges. These voltage spikes originate from lightning strikes, power grid switching, or internal electrical disturbances. Without protection, surges can damage sensitive equipment, disrupt operations, and lead to costly repairs.

To prevent these issues, SPDs detect excessive voltage and divert it safely to the earthing system, ensuring electrical systems remain stable. BS 7671, the UK wiring regulations, outlines conditions where SPDs may be necessary. Since specific requirements depend on factors like system design and risk assessments, consulting a qualified electrical professional is always recommended.

Types of Surge Protection Devices (SPDs)

SPDs fall into three main categories, each providing different levels of protection:

Type 1 SPD – Main Incoming Protection
  • Installed at the origin of the electrical installation, usually in industrial, commercial, and high-risk environments.
  • Handles direct lightning strikes by discharging high-energy surges safely to earth.
  • Protects buildings with lightning protection systems (LPS) or external surge arresters.
  • BS 7671 recognises Type 1 SPDs for installations that require protection against direct lightning strikes.
  • Common applications: Large commercial buildings, industrial sites, and locations with high lightning exposure.
Type 2 SPD – Secondary Protection for Distribution Boards
  • Positioned at the distribution board to safeguard downstream circuits from switching surges and transient overvoltages.
  • Protects equipment like computers, HVAC systems, and automation controls in commercial, industrial, and residential properties.
  • Limits internally generated surges caused by motors, fluorescent lighting, and circuit breakers.
  • BS 7671 specifies conditions where Type 2 SPDs should be installed, particularly when overvoltages pose risks such as loss of life, public service disruption, or financial loss.
  • Common applications: Office buildings, homes, factories, and retail premises.
Type 3 SPD – Localised Device Protection
  • Installed at the equipment level to provide fine protection for sensitive electronics such as computers, medical equipment, and entertainment systems.
  • Works alongside a Type 2 SPD since it cannot handle large surge currents on its own.
  • Available as plug-in adaptors or DIN rail-mounted solutions, making them ideal for specific appliances.
  • Common applications: Workstations, televisions, routers, and other high-value electronics.
SPDs and BS 7671 Compliance

The UK wiring regulations, BS 7671 (IET Wiring Regulations), outline guidelines for installing SPDs. These regulations assess several factors, including:

  • Exposure to external surge risks, such as lightning strikes.
  • Installation type, focusing on safety-critical applications.
  • Potential damage caused by transient overvoltages, including financial loss and equipment failure.

Although BS 7671 provides essential criteria, a qualified electrician should always evaluate an installation to confirm the appropriate SPD setup.

Which Electrical Systems Require SPDs?

SPDs play a crucial role in protecting electrical systems across various settings, including:

  • Commercial Buildings – Shields office computers, servers, and security systems from power surges.
  • Industrial Sites – Prevents damage to motor-driven equipment, control panels, and production machinery.
  • Residential Properties – Preserves smart home devices, electrical appliances, and heating systems.
  • Data Centres – Ensures continuous operation of servers and networking infrastructure.
  • Healthcare Facilities – Protects medical equipment and emergency systems from electrical disruptions.
  • Renewable Energy Installations – Prevents surge-related failures in solar inverters and wind turbine controllers.
Why Install a Surge Protection Device?
  • Prevents Equipment Damage – Stops power surges from degrading electrical components.
  • Reduces Downtime – Minimises costly repairs and operational disruptions.
  • Ensures BS 7671 Compliance – Meets regulatory requirements in installations where surge protection is necessary.
  • Improves Fire Safety – Lowers the risk of fires caused by overvoltage stress on electrical wiring.

Selecting the Right SPD for Your Installation

Choosing the right SPD depends on system voltage, exposure level, and equipment sensitivity. When selecting an SPD, consider:

  • Nominal Voltage (Uₙ) – Matching the SPD to the system’s operating voltage.
  • Maximum Discharge Current (Imax) – Determining the surge-handling capacity required.
  • Installation Location – Identifying whether protection is needed at the main panel, distribution board, or directly at the equipment level.

For comprehensive protection, combining Type 1, Type 2, and Type 3 SPDs creates a layered defence against surges. Since regulations and requirements vary, a qualified professional should assess each installation to ensure compliance with BS 7671 and site-specific needs.

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