Tag Archives: Earth

Wiring Matters – Issue 85 [May 2021]

Here is an overview of what is in the latest edition of the Wiring Matters magazine – Issue 85 [May 2021].

Why have energy efficiency in electrical installations?

A background to Appendix 17 – In summer 2018, BS 7671:2018 (the 18th Edition of the UK’s IET Wiring Regulations) included a new Appendix (17) concerning energy efficiency in electrical installations. The current proposals for Amendment 2 of BS 7671:2018 develop the initial provisions that have been derived from the international standard IEC 60364-8-1 Low Voltage electrical installations – Part 8-1: Energy Efficiency.

With great power comes great responsibility

‘Smart’ is undoubtedly the hot buzzword, both at the wholesalers and when considering options with clients. Domestic and commercial customers are now very aware that there are a host of devices and equipment that can swap out the ‘traditional’ item and offer them greater functionality. These options are increasingly on a par in terms of price, room thermostats being a good example, where Internet of Things (IoT)/Wi-Fi versions are really not much more expensive than their older, physical-button relations.

EICR Myths

Answering some of the most common questions and dispelling the myths associated with the EICR. Since the Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020 came into force on 1 June 2020, the IET technical helpline has been inundated with calls related to the Electrical Installation Condition Report (EICR). This previous IET Wiring Matters article provides further information. In this article, we are going to answer some of the most common questions received and dispel some of the myths associated with the EICR.

Earth leakage

One question being asked in the IET Engineering Communities Forum is ’Earth Leakage Current – How much is too much? This question is being asked more often due to the proliferation of electronic equipment.

Draft for Public Comment for Guide to Implementing Electrified Heat in Domestic Properties

The IET Codes and Guidance team has recently released a draft Guide to Implementing Electrified Heat in Domestic Properties. Prepared for all those involved in this sector, it focuses on all forms of electrified heat as well as other related approaches and technologies.

Elex showcase – discounts, industry forums and more

For those of you missing real-life events, the IET has partnered with Elex to bring you the next best thing – a Virtual Showcase! The showcase offers you everything you’d usually expect to find on the IET stand at an Elex show – discounts on our books and training, the popular IET Industry Forum seminars, and information and webinars around our professional registration offering for the electrical industry, Electrician EngTech.

Can I install a metal consumer unit with a TT earthing system?

High earth fault loop impedance values associated with TT earthing systems mean the earth fault current level is unlikely to be sufficient to operate the distributor’s protective device within the permitted time of 1 second, as required in Regulation 411.2.4, or at all in some cases, depending on Earth resistance values.

There is nothing to prevent a metal consumer unit being installed with a TT earthing system, but it’s important to ensure that an earth fault cannot develop between the meter tails and the metallic enclosure before the RCD.

Methods of reducing an earth faults include keeping the meter tails as short as possible, the installation of proprietary clamps and glands to secure the cables and prevent strain on the terminations, minimising the risk of damage to the meter tails and a subsequent earth fault.