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What’s in Wiring Matters Issue 83 [November 2020]

Let’s take a look at what you can find in Issue 83 of Wiring Matters (November 2020)

The impact of Amendment 2 of the 18th edition (BS 7671:2018+A2:2022)

In this article, we look at the impact that some of the proposed changes in the draft for public comment (DPC) will have on electrical installations. We focus on Chapter 42, Chapter 44 and the new Chapter 82.

COVID-19 and how it has changed the way we work

Steven Devine talks about some of the effects that COVID-19 has had on the industry.

Current-carrying capacity of cables installed in concrete cable troughs

A discussion regarding the maximum number of cables that can be installed in a pre-formed concrete cable trough?

How I became a Chartered Engineer

Michael Peace shares his experience of becoming a Chartered Engineer.

Section 514 identification and notices in the Amendment No. 2 Draft for Public Comment

The draft for public comment (DPC) of Amendment No. 2 to BS 7671:2018 contains proposed changes to Section 514 Identification and notices. This article provides an overview of those proposed changes, and the reasons behind them.

Sponsored: Surge Protection – what you need to know

Surge protection devices (SPD) are a requirement under the 18th Edition of the Wiring Regulations and essential in protecting equipment from damage. Here, Dominick Sandford, Director and Head of Merchandising & Marketing at ElectricalDirect explains the requirements.

New plans to make UK world leader in green energy

The Prime Minister has set out new plans to Build Back Greener by making the UK the world leader in clean wind energy – creating jobs, slashing carbon emissions and boosting exports.

£160 million will be made available to upgrade ports and infrastructure across communities like in Teesside and Humber in Northern England, Scotland and Wales to hugely increase our offshore wind capacity, which is already the largest in the world and currently meets 10 per cent of our electricity demand.

This new investment will see around 2,000 construction jobs rapidly created and will enable the sector to support up to 60,000 jobs directly and indirectly by 2030 in ports, factories and the supply chains, manufacturing the next-generation of offshore wind turbines and delivering clean energy to the UK.

Through this, UK businesses including smaller suppliers will be well-placed to win orders and further investment from energy companies around the world and increase their competitive standing on the global stage, as well as supporting low-carbon supply chains.

The Prime Minister has also set out further commitments to ensure that, within the decade, the UK will be at the forefront of the green industrial revolution as we accelerate our progress towards net zero emissions by 2050.

These include:

  • Confirming offshore wind will produce more than enough electricity to power every home in the country by 2030, based on current electricity usage, boosting the government’s previous 30GW target to 40GW.
  • Creating a new target for floating offshore wind to deliver 1GW of energy by 2030, which is over 15 times the current volumes worldwide. Building on the strengths of our North Sea, this brand new technology allows wind farms to be built further out to sea in deeper waters, boosting capacity even further where winds are strongest and ensuring the UK remains at the forefront of the next generation of clean energy.
  • Setting a target to support up to double the capacity of renewable energy in the next Contracts for Difference auction, which will open in late 2021 – providing enough clean, low cost energy to power up to 10 million homes

These commitments are the first stage outlined as part of the Prime Minister’s ten-point plan for a green industrial revolution, which will be set out fully later this year. This is expected to include ambitious targets and major investment into industries, innovation and infrastructure that will accelerate the UK’s path to net zero by 2050.

Prime Minister Boris Johnson said:

Our seas hold immense potential to power our homes and communities with low-cost green energy and we are already leading the way in harnessing its strengths.

Now, as we build back better we must build back greener. So we are committing to new ambitious targets and investment into wind power to accelerate our progress towards net zero emissions by 2050.

This sets us on our path towards a green industrial revolution, which will provide tens of thousands of highly-skilled jobs.

Together with planned stringent requirements on supporting UK manufacturers in government-backed renewables projects, these measures will mean the industry can reach its target of 60% of offshore wind farm content coming from the UK.

Business and Energy Secretary Alok Sharma said:

The offshore wind sector is a major British success story, providing cheap, green electricity while supporting thousands of good-quality jobs.

Powering every home in the country through offshore wind is hugely ambitious, but it’s exactly this kind of ambition which will mean we can build back greener and reach net zero emissions by 2050.

Today’s announcement marks the latest stage of the government’s support for renewable energy. Last September the third round of the Contracts for Difference renewable energy auction delivered record-low prices on enough clean energy to power 7 million homes. Earlier this year the government announced the next round would be open to onshore wind and solar projects for the first time since 2015.

The UK has the largest installed capacity of offshore wind in the world, with around 10GW in operation off its coasts.

The government’s plan for renewable energy forms part of wider efforts to ensure the UK meets its legally binding target to reach net zero emissions by 2050 and build back greener from coronavirus.

Over the past decade, the UK has cut carbon emissions by more than any similar developed country. In 2019, UK emissions were 42 per cent lower than in 1990, while our economy over the same period grew by 72 per cent.

Hugh McNeal, CEO of RenewableUK, said:

The government has raised the ambition for offshore wind and renewables, and our industry is ready to meet the challenge. A green recovery with renewables at its heart will be good for consumers and jobs, as well as helping to meet our 2050 net zero emissions target. Support for new floating wind projects will ensure the UK stays at the forefront of global innovation in renewables, and provides new opportunities in the low carbon transition.

Energy UK’s Chief Executive, Emma Pinchbeck, said:

The UK’s power sector has reduced emissions by nearly 70%, but we know we need to go further and faster on the road to Net Zero. The energy industry will work with Government to turn our world-leading low carbon power sector into a Green Recovery for the whole economy.

The package of support for offshore and floating wind announced by the Prime Minister today takes a UK decarbonisation success story and winds it up to a scale fit for the Green Recovery, creating jobs and billions of pounds of investment.

We need to build back better for the environment, for the economy and for communities. We look forward to the Prime Minister’s ten-point plan for the low carbon industrial revolution, later this autumn.

Keith Anderson, CEO of ScottishPower, said:

These bold ambitions and clear targets are exactly the right signals at exactly the right time. They will encourage long-term investment and innovation from the renewables industry – and they will boost employment and economic benefits right across the UK. ScottishPower is committed to doubling down on our commitments to delivering 100% clean green energy that matches the UK’s aim to cut emissions for every home.

Benj Sykes, Industry Chair of OWIC, said:

Offshore wind is on track to become the backbone of Britain’s electricity system, providing reliable, low-cost clean power to homes and businesses across the country. The industry is investing tens of billions of pounds in new offshore wind projects, supporting local economies and employment in communities across the UK. Our global leadership in offshore wind, coupled with new support for investment in ports, will help unlock the huge opportunity for the UK to build a world-leading, competitive supply chain.

Alistair Phillips-Davies, CEO of SSE, said:

We welcome today’s announcement which will help ensure that more low cost offshore wind can be deployed before 2030, creating green jobs and putting the UK on the right path to net zero. This complements SSE’s own plans to invest over £7.5 billion in low carbon infrastructure over the next five years, including building the largest offshore wind farm in the world at Dogger Bank with Equinor.

Dame Carolyn Fairbairn, CBI Director-General, said:

Fuelling a sustainable economic recovery by reigniting business investment and creating green jobs is the right response to the challenges unleashed by COVID-19.

A low-carbon power system will underpin the green industrial revolution. Investment in port infrastructure and opening up already successful auctions for renewable electricity will help accelerate construction of offshore wind farms and secure low-cost renewable power for homes and businesses.

Duncan Clark, Head of UK Region for Ørsted said:

We welcome today’s announcement from the government which will unlock huge opportunities for world class UK supply chain companies, both domestically and overseas, to market the skills and innovative technologies that have been fostered in the UK offshore wind industry.

Offshore wind is the most cost effective way to achieve the UK’s net zero ambitions and delivering 40 GW of offshore wind by 2030 is an essential part of this roadmap. This is a challenging target but achievable if Government and the industry continue to work together to accelerate deployment and build out the UK project pipeline as quickly as possible, regenerating coastal communities while expediting our progress to a more sustainable, low-carbon future.

Dr Nina Skorupska, Chief Executive of the Association for Renewable and Clean Technology (REA) said:

We welcome this important commitment from the Prime Minister to lead a Green Industrial Revolution. The REA has long advocated that the UK can be powered safely and securely by renewable energy. We look forward to working with his Departments on further exciting opportunities for delivering renewable heat and transport and other renewable power technologies and flexibility markets also vital for meeting our Net Zero commitments.

Sabrina Malpede, ACT Blade, Managing Director said:

We are delighted to hear of the government’s plan to support clean wind power development in the UK. Investing in this industry has real potential to create jobs, boost productivity and promote sustainable growth. At ACT Blade, we strive to support wind energy development by contributing to lower its cost. We hope the Build Back Greener plan includes support for innovative technologies and its commercialization, as well as promote policies for a real clean energy transition.

Claire Mack, Chief Executive of Scottish Renewables, said:

The Prime Minister is right to acknowledge the UK’s renewable energy resource as one of the best in the world and right to focus on the development of wind power, as part of a balanced green energy mix, as a key way to power the UK’s green economic recovery.

All parts of the UK can and should benefit from the development of this resource and the renewable energy industry in Scotland looks forward to working alongside government to deliver jobs, investment and innovation as we move towards our ambitious net-zero targets.

Steve Scrimshaw, Vice President, Siemens Energy UK&I, said:

This is an ambitious announcement by the government. Offshore wind with hydrogen energy storage can provide reliable clean energy and will be vital to achieving net zero. The UK’s unique position means we can be at the forefront of developing deeper sea waters and the supply chain will welcome the commitment from Government in this innovative area.

Julian Brown, Vice President and UK Country Manager of MHI Vestas Offshore Wind said:

We strongly support the government’s plans to Build Back Greener! In addition to confirming the immense role offshore wind will have in the UK’s clean growth, the government’s injection of vital funds into ports and manufacturing locations will provide a real boost towards the realisation of many thousands of UK offshore wind jobs. This is truly a step forward for the UK’s green economic recovery.

Tom Glover, RWE UK Country Chair, RWE Renewables, said:

As one of the world’s leading companies for renewable energy, committed to be carbon neutral by 2040 and to grow our renewables portfolio in the UK, RWE welcomes the package of measures to further develop UK offshore wind sector announced by the Prime Minister today. This major step further cements the UK as one of the most attractive markets for investment in offshore wind. We will work with the government and the wider energy industry to deliver these ambitions, creating thousands of jobs and billions of pounds of investment. We look forward to the Prime Minister’s ten point plan for a green industrial revolution which we hope will include measures to overcome some of the restrictions to rolling out renewable energy even faster, such as the significant and co-ordinated investment in our grid infrastructure.

Mike Hughes, Zone President, Schneider Electric UK & Ireland, said:

We welcome today’s news of a substantial investment in next-generation offshore wind projects.

Green technologies hold huge potential to enhance the skills, know-how, and production capabilities across the UK, while also supporting our collective progress towards net zero emissions with high-quality products and technologies developed here in the UK.

We believe there has never been a better time to invest in renewables technology production, as the UK prepares to hosts the milestone 26th UN Climate Change Conference (COP26) next year.

Today, the UK today is already a world scale leader in offshore wind energy, as we pride ourselves on up to 40% renewable energy in our country’s electricity balance. Further investment in making the UK the world leader in low-cost green energy production will fuel growth while keeping costs and emissions in check.

Wiring Matters – Issue 81 – July 2020

Wiring Matters – Issue 81 – July 2020

Here is what you will find in the July 2020 (Issue 81) of the IET Wiring Matters magazine.

History of insulation resistance testing

There has been a lot of activity on the IET Engineering Communities forum recently regarding the background of the 1 megohm minimum value for insulation resistance. Let’s take a look at how this value was arrived at in BS 7671:2018+A1:2020.

Draft for Public Comment: IET Code of Practice for Electrical Energy Storage Systems, 2nd Edition

The IET are happy to announce that the Draft for Public Comment for IET Code of Practice for Electrical Energy Storage Systems 2nd Edition is now live.

This Code of Practice looks at Electrical Energy Storage System (EESS) applications and provides information for practitioners to safely and effectively specify, design, install, commission, operate and maintain a system. This 2nd Edition has been updated to take account of developments in the industry, and progress in standardisation.

The all-new 5th Edition of the IET Code of Practice for In-Service Inspection and Testing of Electrical Equipment

In this article, James Eade, author of the 5th Edition, gives a brief insight into the changes to this important Code, due for publication later this year.

Amps per Pound

The idea of sizing a cable to reduce energy loss in distribution is nothing new and has been considered for many years, but with competitive tendering for work and the continual search for cost reductions (also known as ‘value engineering’), the modern design of an electrical installation tries to reduce the materials utilised to a minimum.

Asbestos guidance for electricians

Asbestos was widely used in building construction, both as a building material and for its useful insulation and fire protection properties, for many years during the 20th century.

Its use was progressively reduced between the 1970s and 1999 when all remaining forms were finally prohibited in the UK with the implementation of the Asbestos (Prohibitions) (Amendment) Regulations 1999. Asbestos has also been removed from various properties over the years for various reasons, for example, because of damaged material, or for refurbishment and demolition, but a substantial proportion of the original products still remain. These materials, if undetected, can present an ongoing risk to workers carrying out building repair and maintenance or improvement and refurbishment work. Workers at potential risk include electricians and other building trades. 

Amendment number 1 to BS 7671:2018+A1

Amendment 1 of BS 7671:2018 was published at the beginning of February this year and may be implemented immediately. The amendment concerns Section 722 of BS 7671:2018 (electric vehicle charging installations). In this article, we give a brief overview of some of the main changes to Section 722.

Protection against electric shock

Regulation 722.411.4.1 concerning the use of protective multiple earthing (PME) supply has been redrafted. Indent (iii) has been fully revised. In addition, Regulation 722.411.4.1 now includes an additional indent (iv) to cover single-phase installations and a further additional indent (v) has been added. Regulation 722.411.4.1 does not allow PME to be used to supply an electric vehicle (EV) charging point located outdoors (or that might be used to charge a vehicle located outdoors) unless you meet (i) or (ii) or (iii) or (iv) or (v) of 722.411.4.1.

A summary of the requirements of the indents to Regulation 722.411.4.1 is as follows.

Regulation 722.411.4.1(i) refers to a situation where a connecting point is supplied from a three-phase installation used to supply loads other than charging points and where the load is sufficiently well balanced.

Regulation 722.411.4.1(ii) requires a very low resistance earth electrode to mitigate the effects of an open-circuit (PEN) conductor fault on the supply.

Regulation 722.411.4.1 (iii) has been revised and refers to a voltage monitoring device (or functionality within the charging equipment) that detects PEN conductor failure. The informative Annex to Section 722 describes that suitable arrangements include measurement of the voltage between either:

   a. the circuit protective conductor (CPC) and a suitable measurement earth electrode, or
   b. the CPC and a reference point derived from the line conductors of a three-phase system provided that suitable precautions are also taken to disconnect the device when the supply to one or more of the line conductors is interrupted.

Regulation 722.411.4.1 now includes an additional new indent (iv) to cover protection by a device (or functionality within the charging equipment) for a single-phase installation.

Finally, Regulation 722.411.4.1 includes an additional new indent (v), which allows protection against electric shock to be provided by the use of an alternative device to those in (iii) or (iv), providing that it does not result in a lesser degree of safety than using (iii) or (iv). The indent states that equivalent means of functionality could be included within the charging equipment.

The touch voltage threshold of 70 V mentioned in Regulation 722.411.4.1 is on the basis that Table 2c (ventricular fibrillation for alternating current 50/60 Hz) of IEC 60479-5{ed1.0} gives a value of 71 V for both-hands-to-feet, in water-wet conditions with medium contact area (12.5 cm2).

Regulation 722.411.4.1 includes some important notes. Note 5 explains that BS 7671 does not deal with the safety requirements for the construction of electrical equipment. Where equipment to be used is not covered by a British or Harmonized Standard, the electrical installation designer should establish that the manufacturer of the equipment has ensured that the equipment satisfies the safety objectives of the relevant directive(s).

Note 6 states that creating a TT earthing system for charging equipment or for the whole installation, as an alternative to using a PME earthing facility with one of methods (i) to (v) above, may not be an appropriate solution, due to the inability to provide sufficient separation from buried metalwork connected to the supply PEN conductor.

What is protective multiple earthing (PME)?

The Electricity Safety, Quality and Continuity Regulations 2002 (ESQCR) (as amended) permit the distributor to combine neutral and protective functions in a single conductor, provided that (in addition to the neutral to Earth connection at the supply transformer) there are one or more other connections with Earth. The supply neutral may then be used to connect the CPCs of the customer’s installation with Earth if the customer’s installation meets the requirements of BS 7671.

PME has been almost universally adopted by distributors in the UK as an effective and reliable method of providing their customers with an earth connection. Such a supply system is described in BS 7671 as TN-C-S. However, whilst a PME terminal provides an effective and reliable facility for the majority of installations, under certain supply system fault conditions (external to the installation), a potential can develop between the conductive parts connected to the PME earth terminal and the general mass of Earth.

The potential difference between true Earth and the PME earth terminal is of importance when:

   a. body contact resistance is low (little clothing, damp/wet conditions), and/or
   b. there is relatively good contact with true Earth. 

Contact with Earth is always possible outside a building and, if exposed-conductive-parts and/or extraneous-conductive-parts connected to the PME earth terminal are accessible outside the building, people may be subjected to a voltage difference appearing between these parts and Earth.

Residual current device (RCD) protection

The requirements for RCD protection have been redrafted. The Regulation now contains further requirements for Type B and Type A or Type F RCDs, to take account of DC fault current, as follows (extract below):

“Except where provided by the EV charging equipment, protection against DC fault currents shall be provided by:

(i) an RCD Type B, or

(ii) an RCD Type A or Type F in conjunction with a residual direct current detecting device (RDC-DD) complying with BS IEC 62955 as appropriate to the nature of the residual and superimposed currents and recommendation of the manufacturer of the charging equipment.”

ANNEX A722 (Informative)

Annex A722 has been redrafted. This Annex now includes guidance on the voltage monitoring device described in Regulation 722.411.4.1 (iii). In addition, the Annex now includes an example arrangement of a separated system as described in Regulation 722.413. 

Conclusion

It is important to note that this article gives only a very brief overview of some of the changes in the Amendment to BS 7671:2018. For more information, please refer to BS 7671:2018, Amendment 1:2020.

By: Geoff Cronshaw – IET Wiring Matters – Issue 79

Wiring Matters – Issue 79 – March 2020

Issue 79 (March 2020) of Wiring Matters includes articles on Amendment 1 to BS 7671, the private rented sector, the Electrotechnical Assessment Specification and the return of our Mythbusters column.

Amendment number 1 to BS 7671:2018+A1

Amendment 1 of BS 7671:2018 was published at the beginning of February this year and may be implemented immediately. The amendment concerns Section 722 of BS 7671:2018 (electric vehicle charging installations). In this article, we give a brief overview of some of the main changes to Section 722.

The Electrotechnical Assessment Specification – January 2020 Edition

The Electrotechnical Assessment Specification (EAS) Committee is made up of a wide range of experts who are passionate about the electrotechnical industry. It includes representatives from the competent person scheme providers, certification and registration bodies, industry trade associations, the Ministry of Housing, Communities and Local Government, the Health and Safety Executive, Electrical Safety First and the IET (which also provides administrative support to the committee).

Mythbuster #5 – Will any old terminal block do?

In this issue, James Eade investigates terminals and connectors.

The Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020

Between 17 February and 16 April 2018, the government invited comments on the Electrical Safety Standards Working Group’s decision to make a recommendation to introduce mandatory inspection and testing for private rented properties.

Getting important labelling right leaves a lasting impression

What you leave behind after an installation speaks volumes. While electrical labelling is most importantly about safety, it should also be convenient, professional, time-saving, making your life easier and leave a lasting impression with your customers.

You can read the full story’s here