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NEWS Wiring Matters – Technical considerations for d.c. installations

Interest in utilising d.c. power systems within buildings is on the increase, for various applications relating to:

  • Distributed / local energy generation and storage
  • Electronic devices
  • Data centre installations
  • LED lighting

Our Principal, Graham Kenyon, has written an article for the IET’s Wiring Matters, which discusses the challenges that are presented by what could be seen as a change of direction for wiring systems in buildings.

The article can be found here: Wiring Matters – Technical considerations for d.c. installations

IET Wiring Matters

Note: G Kenyon Technology Ltd is not responsible for the contents of other web-sites.

RCD Protection for Sockets in BS7671: 2008(2015)

The IET Wiring Regulations, 17th Edition, BS7671: 2008, incorporating the 3rd Amendment (2015) was published on 1st January 2015, and comes into force for new designs from 1st July 2015 inclusive, as stated in the Introduction to the third amendment, 2015.

Some of the key changes should be particularly noted by designers of electrical installations.

One such change, in relation to Protection Against Electric Shock, is that of Regulation 411.3.3, whereby all socket outlets rated 20 A or less in a.c. systems must hence have 30 mA RCD protection, unless labelled / identified for a specific item of equipment, or, for installations other than dwellings, where a documented risk assessment has determined RCD protection is not necessary.

The changes to the Regulation should be considered by designers of installations for use with information technology equipment. The use of RCDs with such installations needs particular care, to avoid nuisance-tripping and loss of valuable service / data. Under these circumstances, the alternative provisions of Regulation 411.3.3 are available to the Designer, but, as indicated by BS7671, this should be backed up by relevant documentation as part of the design.

Where the risk assessment is undertaken as part of the design, due consideration of the intended use of the premises, and its operation and maintenance, is important. Ideally, the employer responsible for the installation in use and maintenance should be involved in that process.

It would also follow that relevant risk assessment information is taken into account for, and provided with, Operation & Maintenance manual information for the installation.

Further information on the standard and its related Guidance Notes and other publications can be found on the web-site of the Institution of Engineering and Technology: http://electrical.theiet.org/

Note: G Kenyon Technology Ltd is not responsible for the contents of other web-sites.

Are Safety Socket Covers a good idea for UK Sockets?

Scorched Socket on Fatally Flawed web-site

In many countries, socket outlets do not currently have built-in safety shutters to prevent access to live electricity with the plug removed, and in those countries using a “safety socket cover”, or “socket protector” may well be an excellent idea to help prevent children accessing live electricity, provided they are properly manufactured.

In the United Kingdom, however, British Standard socket outlets to BS 1363 have for decades incorporated safety shutters which are slowly opened as the plug is inserted.

The Fatally Flawed web-site discusses the issues that can be encountered using certain safety socket covers with BS 1363 socket outlets, which have apparently included instances of certain safety shutter systems being defeated if a cover is improperly used, or perhaps breaks.

It is certainly prudent for individuals and businesses to consider carefully the potential consequences of using socket covers with UK socket outlets, and balance these against the risks of not using them, which should take into account the safety measures already in place.

Note: G Kenyon Technology Ltd is not responsible for the contents of other web-sites.