Colin McAhren, Technical Business Development Manager at BG Electrical, looks at the recent changes brought about by the 18th Edition Wiring Regulations:
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“The 18th edition wiring regulations introduced many new rules to the electrical industry. One of the biggest changes came through the total re-write of regulations and guidance on protection against overvoltage and risk assessment, and how to calculate if surge arrestors are required or not.
AFDDs, a totally new protection device was included, there was also EV charging point installation guidance, as well as regulations covering unwanted tripping, interacting with regulations covering division of circuits, and types of RCD to use for a given application. It was no surprise that many questions were asked!”
The most frequently asked questions have typically been around:
1. Surge protection regulation 443.4. 2. Arc fault protection regulation 421.1.7.
3. Unwanted tripping 531.3.2. 4. RCD types and applications.
Regulation 443.4 Surge Protection – Overvoltage control
This regulation states overvoltage protection shall be provided where the result of an overvoltage would affect specific aspects, such as danger to life, public services, commercial or industrial activity and where there is a number of co-located individuals.
As a rule of thumb, if the application is commercial, industrial or where large numbers of individuals are gathered e.g. churches, galleries etc., it falls as a mandatory requirement, surge protection must be part of the installation.
Residential installations are not mandatory, but the cost of the install and equipment fitted must be considered and protection against voltage surge may help in the preservation of electronic
components in flat screen TVs, modern electrical equipment and LED lighting systems. The electronics are at risk to high voltage surges.
The device most widely employed is a T2 overvoltage device. (It should be noted that this device does not protect against lightning strikes, but for more detailed information on this, please contact us.) For lighting strike, T1 used in conjunction with T2 surge arrestors are used as well as a sophisticated earthing arrangement. This is frequently used for commercial and industrial applications.
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| Wiring Devices and Accessories
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