Regulation 443.4 of the new 18th Edition Wiring Regulations addresses the issue of surge protection and the risks associated with excess voltage. Surge protection devices (SPD’s) are designed to prevent damage to wiring infrastructures and electric shocks due to excess voltage from atmospheric or switching origins.
The update requires a surge protection device to be installed where overvoltage could result in loss of life or serious injury, interrupted public services or industrial and commercial activity, damage to cultural heritage or where a large number of people at the same location could be affected.
Under other circumstances a risk assessment must be carried out to see if protection is necessary. The risk assessment calculation is based on a formula that uses values that are given in table 443.1 along with values related to geographical locations of the UK shown in fig. 44.2.
If no risk assessment has been carried out then protection must be provided.
The new amendment may exclude single dwellings if the overall value of installation and electrical equipment doesn’t warrant SPD provision.
We are stocking the Schneider EZ9 boards which come with a SPD device already fitted along with a range of SPD’s from Surge Protection Devices Ltd. Call the sales team on 01282 695269 for further information.
Download a bitesize guide to the new 18th Edition regulations for electrical installations, SPD’s and the required risk assessments here.