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SPD Surge Protection Devices

Showing 21–40 of 109 results

WCED WSPD340 WCED Type 2 20kA/40kA 3 Pole Surge Arrestor

WCED WSPD340 Type 2 20kA/40kA 3 Pole Surge Arrestor

1 In stock
More available within 1-3 working days*
SKU: WSPD340
£19.20

3-£18.24£0.96£19.20
5-£17.76£1.44£19.20
10-£17.28£1.92£19.20
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Live Electrical SC440 Live Electrical 4 Pole 20kA/40kA Type 2 Surge Protective Device

Live Electrical 4 Pole 20kA/40kA Type 2 Surge Protective Device

9 In stock
More available within 1-3 working days*
SKU: SC440
£37.55
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WCED WMCUSP432B 3 Phase SPD with 32A Curve B 4 Pole MCB

WCED WMCUSP432B 3 Phase SPD with 32A Curve B 4 Pole MCB

Delivery usually within 1-3 working days*
SKU: WMCUSP432B
£59.90

3-£56.91£3.00£59.90
5-£55.41£4.49£59.90
10-£53.91£5.99£59.90
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Live Electrical SP1401P+N/1 Type 2 SPD Surge Protection Device

Live Electrical SP1401P+N/1 Type 2 SPD Surge Protection Device

Delivery usually within 1-3 working days*
SKU: SP1401P+N/1
£13.67
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FuseBox F1M2SPD Fusebox F1M2SPD Stand Alone Surge Protection Device 1

Fusebox F1M2SPD Stand Alone Surge Protection Device

1 In stock
More available within 1-3 working days*
SKU: F1M2SPD
£54.90
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FuseBox SPDCUKITT1 Fusebox SPDCUKITT1 TYPE 1

Fusebox SPDCUKITT1 Type 1,2 & 3 Surge Protection Device Kit

Delivery usually within 1-3 working days*
SKU: SPDCUKITT1
£109.00
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Live Electrical SA120 Live Electrical 1 Pole 10kA/20kA Type 2 Surge Protective Device

Live Electrical 1 Pole 10kA/20kA Type 2 Surge Protective Device

5 In stock
More available within 1-3 working days*
SKU: SA120
£7.95
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WCED WMCU440SP WCED Metal Surge Arrestor Unit - 100A Main Switch + 40kA Surge Arrestor

WCED Metal Surge Arrestor Unit – 100A Main Switch + 40kA Surge Arrestor

7 In stock
More available within 1-3 working days*
SKU: WMCU440SP
£37.65

3-£35.77£1.88£37.65
5-£34.83£2.82£37.65
10-£33.89£3.77£37.65
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Live Electrical SA240 Live Electrical 2 Pole 20kA/40kA Type 2 Surge Protective Device

Live Electrical 2 Pole 20kA/40kA Type 2 Surge Protective Device

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SKU: SA240
£17.75
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Live Electrical SA420 Live Electrical 4 Pole 10kA/20kA Type 2 Surge Protective Device

Live Electrical 4 Pole 10kA/20kA Type 2 Surge Protective Device

1 In stock
More available within 1-3 working days*
SKU: SA420
£31.55
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Live Electrical SA460 Live Electrical 4 Pole 30kA/60kA Type 2 Surge Protective Device

Live Electrical 4 Pole 30kA/60kA Type 2 Surge Protective Device

Delivery usually within 1-3 working days*
SKU: SA460
£56.95
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Live Electrical SA240CABLE Live Electrical 6mm2 Cable Kit for SPD

Live Electrical 6mm2 Cable Kit for SPD

Delivery usually within 1-3 working days*
SKU: SA240CABLE
£3.58
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Live Electrical SA140/1P+N 2 Pole Type 2 SPD Surge Protection Device

Live Electrical SA140/1P+N 2 Pole Type 2 SPD Surge Protection Device

Delivery usually within 1-3 working days*
SKU: SA140/1P+N
£14.94
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Live Electrical SP1401P+N/2 Type 2 SPD Surge Protection Device

Live Electrical SP1401P+N/2 Type 2 SPD Surge Protection Device

2 In stock
More available within 1-3 working days*
SKU: SP1401P+N/2
£12.03
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Live Electrical SA220 Live Electrical 2 Pole 10kA/20kA Type 2 Surge Protective Device

Live Electrical 2 Pole 10kA/20kA Type 2 Surge Protective Device

10 In stock
More available within 1-3 working days*
SKU: SA220
£15.95
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Surge Devices SY12350KA4P/ENCM Surge Devices Type 1+2+3 50kA 3 Phase Lightning and Surge Arrester with Window Indication & 3P 63A MCB in IP65 Polycarbonate Enclosure

Surge Devices Type 1+2+3 50kA 3 Phase Lightning and Surge Arrester with Window Indication & 3P 63A MCB in IP65 Polycarbonate Enclosure

Delivery usually within 1-3 working days*
SKU: SY12350KA4P/ENCM
£416.97
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Surge Devices SY2-C40XLEDENCM Surge Devices Type 2 20kA/40kA 3 Phase SPD with LED Indication & 3P 32A MCB in IP65 Polycarbonate Enclosure

Surge Devices SY2-C40XLEDENCM Type 2 3 Phase SPD with IP65 Enclosure

Delivery usually within 1-3 working days*
SKU: SY2-C40XLEDENCM
£217.71
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Surge Devices SPDPV600 SPD Type 2 600V DC for Solar/PV Installations

SPD Type 2 600V DC for Solar/PV Installations

1 In stock
More available within 1-3 working days*
SKU: SPDPV600
£77.49

2-£75.94£1.55£77.49
3-£75.17£2.32£77.49
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Surge Devices SPDPV1000 SPD Type 2 1000V DC for Solar/PV Installations

SPD Type 2 1000V DC for Solar/PV Installations

Delivery usually within 1-3 working days*
SKU: SPDPV1000
£107.01

2-£104.87£2.14£107.01
3-£103.80£3.21£107.01
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WCED WSPDTE-2 WCED 2 Pole 2 Module Type 1+2 SPD 1

WCED 2 Pole 2 Module Type 1+2 SPD

1 In stock
More available within 1-3 working days*
SKU: WSPDTE-2
£71.99

3-£68.39£3.60£71.99
5-£66.59£5.40£71.99
10-£64.79£7.20£71.99
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More products

Showing 21–40 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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