When Did SPD Become Mandatory?

Surge Protection Devices (SPDs) have become an integral part of electrical installations to safeguard systems against transient overvoltages. Understanding the timeline and regulations surrounding their mandatory implementation is essential for ensuring compliance and safety.

The Introduction of Mandatory SPDs

The requirement for SPDs became more defined with the release of the 18th Edition of the IET Wiring Regulations (BS 7671), which came into effect in January 2019. This edition included significant updates regarding the use of SPDs, primarily focused on protecting electrical installations from transient overvoltages caused by atmospheric events (like lightning) and switching overvoltages generated within the installation itself.

Key Milestones

1. 18th Edition of BS 7671 (2018):

   • Published in July 2018 and became applicable from January 2019.
   • Introduced comprehensive guidelines for the installation of SPDs based on the risk of transient overvoltages causing harm to life, interruption of public services, or significant financial loss.

2. Amendment 2 of the 18th Edition (2022):

   • Further refined the requirements, making it clear that SPDs must be installed in most installations unless a documented risk assessment determines otherwise.
   • Emphasised the necessity of SPDs in locations where overvoltage could lead to serious injury, loss of life, or significant operational disruptions.

Regulations and Requirements

According to the current BS 7671:2018 + A2:2022 regulations, SPDs are mandatory in several scenarios:

• Where the consequence of overvoltage could result in serious injury or loss of life.
• In instances where overvoltage could lead to failure of safety services, such as fire alarms and emergency lighting.
• When overvoltage might cause significant financial or data loss.
• For buildings supplied by overhead lines, due to higher susceptibility to lightning strikes.

Surge Protection Labels

In addition to the installation of SPDs, proper surge protection device labels must be used to indicate the presence and type of surge protection in place. These labels are crucial for maintenance and safety checks, ensuring that anyone working with the electrical system is aware of the surge protection measures installed.

Risk Assessment

For installations not falling into the categories mentioned above, a risk assessment is required to decide whether SPDs are necessary. This risk assessment must consider factors like the location’s lightning density and the nature of the electrical equipment used.

Conclusion

The regulations surrounding SPDs have evolved to ensure the safety and reliability of electrical installations. The 18th Edition of the IET Wiring Regulations and its subsequent amendments have made the installation of SPDs a critical component for many buildings. Understanding these requirements helps in protecting both people and equipment from potential electrical hazards.

For further detailed guidance, it is advisable to consult the latest version of the BS 7671 standards and seek professional advice when implementing SPDs in your installations.