switched on issue 18

Killer at the gateESC highlights the dangers ofelectrically-powered gates

www.esc.org.uk Issue18 | Autumn 2010 | £5.00

SwitchedOn18.qxd 19/8/10 16:45

2 SwitchedOn Issue 18 - Autumn 2010

WELCOME

FROM THE EDITOR…

So a new government is now in full swing

and looking at how it can reduce the

budget deficit. The level of cuts is potentially

deep and just recently a massive 40%

reduction of spend across government

departments was being mooted; let’s hope

the reality is less harsh for everyone’s sake.

Part of the government’s push to reduce

costs is to ease the burden of regulation on

business, and it is anticipated that many

established regulations, including the

Building Regulations, will at some point

come under the government’s spotlight.

There are some that would welcome the

review of regulations, particularly if it saw

the end of Approved Document P, although

it is the Electrical Safety Council’s view that

Part P is having a positive effect and that its

removal would be detrimental to electrical

safety.

While we have an excellent record for safety

of fixed electrical installations in the UK,

having no controls in place for people

undertaking certain electrical work could,

particularly in difficult economic times, see

an explosion in DIY. This would negate the

efforts of everyone over recent years to

improve the safety of electrical installations

in people’s homes across the UK.

Therefore it was with some concern that we

learnt through correspondence from the

wife of a Part P registered installer that some

registered electricians are willing to notify

work on behalf of others, without even

seeing the work that was undertaken. This

practice could have devastating

consequences for the customer should the

work be defective. It will also make the firm

notifying the work liable should anything

happen and the firm also risks being

prosecuted because it will have taken

responsibility under the requirements of the

Building Regulations.

While we have raised the matter with the

scheme operators, we would ask that if you

are approached to notify work on behalf of

someone else, you point them in the

direction of the local building control

department or, better still, suggest they

register with one of the schemes. After all, if

you have made the decision to invest in

your profession, why shouldn’t they?

Our year-end review occurred at the end of

March and we have been busy developing

the annual report, which this year has a

different look and feel. As a charity we have

a duty to report on the impact, or

otherwise, of our campaigns in respect of

how they helped the beneficiaries of the

Charity. The report is available via our

website, so please download a copy.

As always, we would welcome feedback on

Switched On, to help us improve the

content. Email [email protected]

Phil Buckle

Director General

Keen readers of Switched On will notice

that we’ve introduced a few changes to

the magazine for this issue. We’ve listened

to your feedback about how you use the

magazine and what you would like to see

in it and made some improvements.

We’ve made Switched On easier to navigate

around by introducing clear and simple

signposting to help you distinguish from

news coverage, features and technical

articles. We’ve also given readers a platform

to air their views on any the issues raised in

published articles. The new Letters column

page 6 is there for you as a valuable

feedback mechanism and I urge you to

write in with any concerns, comments or

criticism.

I hope that you like the improvements

we’ve made. Happy reading.

Andrew Brister

Editor

[email protected]


Council partners with Trading Standards - see page 9

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issue 18 Autumn 2010

switchedonyour insight into the electricalsafety industry

Electric shock is not the onlydanger from electricity

Homes made safe by ESCgrants scheme

From the editor…Also, Welcome

News in brief

Plug into Safety campaign sparksthe media’s attention

Letters

Also, Annual consumer survey

ESC publishes two leaflets ondownlighters

Also, ESC schedule of events

Essential Guide to the WiringRegulations

ESC partners with TradingStandards

Have you ever been asked...

Spotlight on…BASEC and cablesafety

Progress of investigation intoin-service reliability of RCDs

Assessing the generalcharacteristics of a domesticelectrical installation

Private tenants at increased riskof electric shock

Investigation into overloadingof four-way extension leads

Exploring the EU Injury Database(IDB) for consumerproduct risk categorisation

SwitchedOn Issue 18 - Autumn 2010 3

Published by:

The Electrical Safety Council

Unit 1.10, Canterbury Court, Kennington

Park Business Centre, 1 - 3 Brixton Road,

London SW9 6DE

www.esc.org.uk

www.eschub.org.uk

www.twothirtyvolts.org.uk

www.switchedonkids.org.uk

Tel: 0870 040 0561 Fax: 0870 040 0560

email: [email protected]



news

Launch of the ESC Hub

Work is progressing on the development of

the ESC Hub. It will bring together the

Electrical Safety Council’s considerable

guidance for industry and provide a central

reference source for electrical installers.

Currently The Hub only provides access to

the Essential Guide, with the remainder of

the Council’s industry publications on its

main website at www.esc.org.uk. However,

in order to provide clearer definition

between the ESC’s industry and consumer

communications, the Council is moving the

technical guidance and industry

communications to The Hub

www.eschub.org.uk.

The Hub will grow to include the full range

of Best Practice Guides, technical articles,

back copies of Switched On magazine and a

user-friendly online version of each current

issue. It will be updated regularly with

industry news and events and the topics

raised via the industry forum will also be

posted regularly. Users will be able to

register to receive regular news and articles

direct from the Electrical Safety Council. Look

out for the launch at the end of the year.

Electrical safety threat in Glasgow

The ESC is warning people in Glasgow about

the dangers of buying counterfeit electrical

goods, following reports from Glasgow City

Council that hundreds of counterfeit GHD

hair straighteners are on sale in the city.

“With 44% of all accidental fires in UK homes

arising from faults or misuse of electrical

goods, we are very concerned for the safety

of anyone in Glasgow who has bought and

is using any sort of counterfeit electrical

goods”, says Steve Curtler, product safety

manager at the ESC.

Further information or advice can be found

at www.esc.org.uk or call the ESC helpline

on 0870 040 0561.

To report counterfeit goods contact

Consumer Direct on 08454 04 05 06.

International Product Safetysymposium takes shape

As reported in the summer issue of Switched

On, the International Consumer Product

Health and Safety Organisation (ICPHSO)

symposium in association with the Electrical

Safety Council is to take place in London on

29 – 30 November.

The 2010 symposium promises to be

outstanding and an event not to be missed.

It will bring together the electrical product

safety community to share information and

to formulate workable solutions for

improving the safety of electrical products in

a truly globalised marketplace.

The Council is taking the lead role in the

plenary session on counterfeiting and will be

presenting at other plenary sessions and

breakout sessions, as well as being an

exhibitor at the event.

Please note that registrations are as always

limited, so to be sure of your place visit the

ICPHSO website www.icphso.org.

For further information on the symposium

and updates on the event programme keep

an eye on our website www.esc.org.uk .

Best Practice Guides - an update

By the time this issue of Switched On is

distributed, two new Best Practice Guides

should have been published:

Best Practice Guide No 7

Test instruments for electrical installations:

Accuracy and consistency

Best Practice Guide No 8

Selection and use of plug-in socket-outlet

test devices

Both guides have been developed by a

Working Group comprising representatives

from the following organisations:

BSI • City & Guilds • Electrical Safety Council

• GAMBICA Association • ECA • ELECSA

• NAPIT • NICEIC • SELECT

The HSE has a particular interest in the

guidance on the selection and use of socket-

outlet test devices, as this had been an area

of concern to it for some time. It is also

hoped that the Institution of Engineering

and Technology will add its support to both

guides.

Until around November, all ESC Best Practice

Guides can continue to be viewed at, or

downloaded free of charge from, the

‘Business and Community’ section of the

main ESC website www.esc.org.uk. After

that, all the information intended for the

electrical industry will be migrated to the

new ‘Electrical Information Hub’ at

www.eschub.org.uk

Work on updating the published Best

Practice Guides on microgeneration (No 3),

and domestic electrical installation condition

reporting (No 4) is now expected to start in

the autumn.

If you have any suggestions for further Best

Practice Guides, please send them to

[email protected]

Amendment 1 to BS 7671: 2008

By the time this issue of Switched On is

distributed, the closing date for comments

on the Draft for Public Comment of the

proposed first amendment to BS 7671: 2008

will have passed. The committee responsible

for the technical content of the standard,

together with its four panels, will have

begun to consider all the comments

received.

BS 7671: 2008 incorporating Amendment No

1 is expected to be published on 1 July 2011

and, following a six-month transition period,

all installations designed after 31 December

2011 will have to comply.

The amendments will not be published as a

separate document, but will be incorporated

in a new full version of the regulations

which, for the first time, will be referred to as

the ‘IET Wiring Regulations’. In accordance

with tradition, the first amendment will have

a green cover.

IN BRIEF



news

The first wave of the ESC’s five-year

flagship campaign – Plug into Safety –

has generated strong media interest, with

coverage across the UK on local radio and

television as well as national and regional press.

Plug into Safety, which aims to promote

awareness of the benefits of RCD protection

to consumers, was launched during May

Bank Holiday – a particularly active time for

both DIY and gardening enthusiasts, who

are the initial focus of the campaign. In the

UK one person a week dies from an

electrical accident in the home and research

indicates that gardeners and DIYers are

most at risk of electric shock or injury. This is

due to their use of hand-held power tools

which have cables or leads that can easily

be cut through and which are often

operated in damp or wet conditions. In

these circumstances particularly, the use of

an RCD can quite simply be a lifesaver.

Despite the safety benefits that RCDs offer,

ESC research found that almost 13 million

homes in the UK do not have adequate RCD

protection; and almost 70% of people are

unaware of what they are.

The Plug into Safety launch was fronted by

the well-known celebrity builder, Tommy

Walsh, but a number of ESC staff also took

to the airwaves to publicise the campaign.

Phil Buckle, director general of the ESC,

undertook a regional radio blitz and was

interviewed by Sky News; and Gary Gundry,

one of the ESC’s senior engineers, featured

on a BBC London television programme.

In addition to coverage in a range of trade

press, the Plug into Safety campaign also

featured in several national newspapers

including The Guardian, The Sunday Mirror

and The Mail on Sunday as well as a host

of regional titles. Coverage is continuing

to filter through into various media

channels, including online sites, and more

features are in the pipeline over the coming

months.

The electrical industry has been extremely

supportive of the campaign and the ESC is

working with key stakeholders including the

fire service, housing providers, government

and electricians in order to take RCDs

mainstream. For example, one way in which

the ESC is engaging with electricians is

through a free toolkit which will provide

them with the key information needed to

inform consumers about the importance of

using RCD protection (see box).

Through collaboration with our partners,

the ESC aims to increase awareness of RCDs

in much the same way that smoke alarms

were promoted by the government in its

‘Fire Kills’ campaign - the campaign

persuaded 70% more households to use the

safety device in their homes.

“The flagship campaign is off to a great

start,” says Cherry Read, head of

communications and campaigns at the ESC.

“We hope, that by focusing on an issue with

such a fundamental and clear safety

message, we will really be able to make a

difference to people’s safety.”

PLUG INTO SAFETY CAMPAIGN SPARKSTHE MEDIA’S ATTENTION

Toolkits forelectricians

Along with the consumer materials

that will be available at point of sale

with retail partners, the ESC is

providing packs to electricians to help

them engage

with their

customers and

convey the

benefits of

having RCD

protection in

their homes.

The pack

will include

50 leaflets

and a

business

card that

electricians

can leave with their customers.

With support from the Electrical Safety

Council, it is hoped that this will enable

more electricians to help their

customers understand the benefits of

RCDs. The packs are available from

wholesalers and industry bodies. To

find out more, email

[email protected]



letters

Ipsos Mori recently completed the

Electrical Safety Council’s fifth annual

consumer survey. It carried out over 2,000

face-to-face interviews and looked at

public understanding of electrical safety

issues in the home, as well as barriers and

motivators for taking action.

The survey asked whether people would

be more likely to attempt electrical DIY in

light of the recession and what factors

would encourage people to choose a

registered competent person.

Word of mouth still key to selecting

electricians

Despite the internet giving people more

ways to get information about

tradespeople, word of mouth is still the

most popular. Almost half (49%) of

respondents said they would be most

likely to use this method rather than

online search engines (4%) or other

directories’ websites (4%). The majority

(70%) would not use any online tools

when searching for an electrician.

Strong support for electrical safety

certification

78% of people believe that it should be a

requirement for landlords to get the

electrics in their properties checked on an

annual basis. Over a quarter of people

(28%) of people already believe that this

measure is in place.

Paying for an electrician in the recession

The current economic situation appears to

be having an impact on the way in which

the British public are approaching DIY

tasks around the home. A significant

number of respondents indicated that,

due to the recession, they would be

prepared to carry out electrical DIY

themselves, or ask friends or relatives to

undertake work, rather than pay for a

professional to do it. Almost a quarter

(22%) said that they are now more likely

attempt to wire in new sockets or install

an oven without an electrician and, most

alarmingly, one in ten said they would do

likewise when rewiring a part, or all, of

their house.

I was delighted to read about the launch of

the ESC’s Plug Into Safety campaign in the

last issue of Switched On magazine: as the

company that first launched RCD adaptors in

the UK and has pioneered RCD use for the

past 35 years, it’s a campaign that we at

GreenBrook wholeheartedly support.

However, this campaign is about educating

the marketplace and ensuring that both

those that specify RCDs and those that use

them in the home are familiar with all the

products available so that they can select the

best solution for their needs. What I was left

asking myself after I’d read your article was -

how can this education campaign hope to

succeed if many of the most popular and

widely-used RCD product types are not even

mentioned in the media coverage?

While the article discussed the importance of

consumer board units and portable adaptors,

no mention was made at all of RCD sockets

or fused spurs, both of which are best sellers.

Leaving out these product types from any

discussion fails to educate the marketplace

and, ultimately, will fail to increase levels of

safety. The stark facts are that almost 10% of

all fires in the UK are caused by electrical

faults of one kind or another and that

equates to just over 20,000 fires every year!

What’s more, 50% of UK homes still do not

have RCD protection (that’s 13 million

homes), all of which highlights the need for

better understanding of the role of RCD

protection and the varied forms it can take.

Obviously, in the commercial world everyone

wants to sell the products that will help

them develop market share, but the issues at

stake here are more than simply commercial

– this is a matter of life and death. That’s why

my recent presentation on RCDs to the

Electrical Distributors’ Association (EDA)

covered product types that GreenBrook

doesn’t even sell and why I would urge

anyone else involved in the manufacture,

promotion or sale of RCDs to focus on a clear,

representative safety message, regardless of

their own commercial interests.

It’s time we all did our bit to improve

electrical safety in the home and that means

educating the public...not misleading them.

Richard Shaw

Managing Director

GreenBrook Electrical

The ESC replies: The early stages of the Plug

into Safety campaign needs to raise

awareness of RCDs and the additional

protection they provide. In our annual

consumer survey, 60% of respondents stated

that they didn’t know what an RCD was and

8% gave the wrong answer when asked to

explain what it is (Source: MORI, April 2010).

In order to get the RCD message to people

when they are most receptive, the Council

felt it important initially to target people

when they are gardening or doing DIY or

when an electrician is already working on

their home/property. We therefore felt it

most important to promote RCD adaptors

and consumer unit replacement, particularly

in the first year.

By focusing on these two most accessible

examples of RCD use we hope to ‘introduce’

the benefits of RCD protection in the

simplest possible fashion. Experience has

taught us that if we promote too complex, or

too many messages, we are likely to confuse

people. As we are planning to run this

campaign over a five-year period, we will be

referring to the various kind s of RCDs

available in future activity.

And in reference to the 50% figure quoted

in the letter – 13 million homes do not

have adequate RCD protection, rather that

none at all.

Angela Murphy

Media Manager

Electrical Safety Council

ANNUALCONSUMERSURVEY 2010

What about RCD sockets?

Letters We hope you like the new Letters

column. Now all we need to do is

to fill it regularly!

I’m sure that there are many within theelectrical industry that will have strongfeelings about some of the issues raisedin Switched On. So feel free to shoutabout them.

Please email your letters [email protected]

Please note that we will not be able to enter into

correspondence regarding every letter received, nor

will we have the space to publish every viewpoint.

We reserve the right to edit letters for publication.



news

With a busy schedule of events behind

us, the year will end with the Electrical

Safety Council’s attendance at the Party

Political Conferences in September and

October and a packed two days at the Elex

Show at Sandown Park on 30 November and

1 December.

Attendance at the Party Political Conferences

has given the Council valuable opportunities

to liaise with ministers and MPs as part of its

public affairs programme of activity and will

again provide access to key decision makers

and influencers within government and

opposition. The ESC’s public affairs work is

focused on improving regulation, especially

in the private rented sector, working with

landlords to help them keep their tenants

and properties safe.

Elex provides the ESC with the opportunity

to hear first hand about the issues affecting

electrical contractors working around

the country and to show electricians the

whole host of consumer literature and

best practice guidance that the ESC has

to offer.

The Electrical Safety Council is also proud

to host an industry forum at Elex, bringing

together panel members from Elecsa,

NAPIT and NICEIC to discuss issues of

importance to installers. The forum has

been very well attended in the past

and has produced some interesting

debate on:

• Alterations and Additions — applying the

regulations;

• Periodic Inspection Reports – proposed

change to Electrical Installation Condition

Report, which will come in as part of

Amendment 1 to BS 7671.

ESC CONTINUES BUSY EVENT SCHEDULEAT ELEX AND PARTY CONFERENCES

Two leaflets in the form of quick

reference guides have been

produced (in association with other

leading bodies) to draw attention to

the hazards associated with

downlighters. The first is aimed at

helping the trade to select and install

them correctly, and the second

targets householders to raise

awareness of the importance of

selecting the correct type and rating

of replacement lamps.

The guides have been produced in

response to the conclusions from the

Council’s investigations into claims

that downlighters may have been the

cause of a significant number of fires

in homes.

It is hoped that retailers and electrical

wholesalers will demonstrate their

support to this initiative by making

the guides available at outlets where

downlighters can be purchased.

ESC PUBLISHES TWO LEAFLETS ON DOWNLIGHTERS

The guides are available to view and download from the website at www.esc.org.uk

Tickets for Elex are available free of charge.

Please register your interest at [email protected] or visit www.elexshow.com


As announced in the Spring issue of

Switched On, the ESC has made its

definitive guide to complying with BS 7671

(IEE Wiring Regulations) and related standards

available to all* - online.

Fully updated to the ‘17th Edition’, The

Essential Guide to the Wiring Regulations is a

unique and authoritative source of reference

on electrical installation safety matters. It’s

the definitive guide to complying with the

requirements of BS 7671, and related

standards, for the electrical contracting

industry and other qualified practitioners.

The relevant requirements of BS 7671, other

British Standards and Industry Codes of

Practice are identified and amplified, and

their implications explained. Many topics

also incorporate data and other useful

information on the subjects they cover.

Formerly known as ‘the Technical Manual’, the

constantly-developing Guide, which has

already been many years in the making,

currently comprises over 330 illustrated

topics.

In printed form, the topics would fill at least

four large A4 binders. However, in this

electronic age, all the topics are fully

searchable on screen, and are hyperlinked to

related topics. All the published topics are

kept under review, and are updated as and

when necessary.

The Essential Guide is growing at the rate of

about 40 new and significantly revised topics

per year towards a target of 800 topics. But

there’s no need to download updates – the

latest version of the Guide is always the one

online.

However, for those who might prefer to keep

some of the essential information at their

fingertips on paper, each of the topics is

printable in full colour as a PDF.

The online version contains a range of

interactive features, including:

• Your popular searches

• Your reading list

• What’s new

• Options for comments and feedback.

• Dynamic search options and links

Forthcoming topics will cover aspects of the

following subjects:

• Fused connection units

• Replacement of accessories

• Building Regulations Approved

Documents (England and Wales)

• Installation of electric central heating boilers

• Busbar trunking systems – current-

carrying capacity and voltage drop

• Foil sheathed cables to BS 8436 -

protective device requirements

• Extra-low voltage lighting

• Recessed downlighters – fire performance

• Use of small generators to supply mobile

or transportable units

• Adequacy of 16 mm2 meter tails and

10 mm2 earthing conductors in existing

domestic installations

• Caravans and caravan parks

• Construction sites

In addition to the wide range of topics,

subscribers to the online Essential Guide will

gain access to additional technical material,

including the latest BEAMA Guides.

The intended users of the Essential Guide are

persons trained to at least National

Vocational Qualification (NVQ) Level 2 in

electrical installation work, and having a

good understanding of the requirements of

BS 7671 and related standards.

The Essential Guide is a valuable source of

technical information and guidance for all

those involved in electrical installation and

allied work, including:

• electrical engineers

• electrical installation designers

• electrical contractors and installers

• building services engineers

• building services maintenance engineers

• colleges and training bodies

• electrical equipment manufacturers

• housing associations

• local authority building control and

environmental services departments

• NHS Trusts

• Facilities management companies

A 12-month subscription to the online

Essential Guide to the Wiring Regulations

currently costs only £85 plus VAT, which is

exceptionally good value. But the price is

under review, so don’t delay.

*By arrangement with the Council’s trading

subsidiary NICEIC Group Ltd, the online version

continues to be available free of charge to

NICEIC Approved Contractors, NICEIC Domestic

Installers and to NICEIC Partners.


news

YOUR ESSENTIAL GUIDE TO THE WIRING REGULATIONS

Subscribe at the ESC’s new ElectricalInformation Hub at www.eschub.org.uk



news

The consumer watchdog Trading

Standards has become the latest partner

of the Electrical Safety Council, joining forces

to help combat the issue of product safety.

We reported in the last issue of Switched On

that the Council is working hard to combat

the increasing volume of counterfeit and

dangerous electrical products available in

the UK, some of which pose a high risk of

serious injury or fire.

In a bid to combat the growing market in

unsafe goods, the collaboration between the

Electrical Safety Council and Trading

Standards hopes to use the knowledge and

position that each has within their fields to

ensure that information relating to unsafe

electrical products can be shared via a

secure online microsite which will enable

information to be accessible to Trading

Standards Officers out in the field.

The aim of the mircosite is to:

• provide a database of recalls of electrical

products which can then be shared with

the wider public via individual websites

• build a strong partnership and

knowledge database in relation to

electrical recalls that may be used in the

future to clamp down on counterfeiting

and unsafe products

• encourage joint activity where resources

can be shared for mutual benefit, eg.

independent product testing and

investigations, regional/national

consumer awareness campaigns, funding

for local consumer safety activities,

regional projects, etc.

The Electrical Safety Council is keen to

extend partnerships within the industry and

hopes that this new arrangement with

Trading Standards will provide a wider

benefit to the public as a whole.

To further cement the close working

relationship and to reinforce the two bodies’

shared passion for consumer safety, the

Council was the main sponsor at TSI’s

conference and exhibition which took place

in Edinburgh in June. Trading Standards

Institute’s annual conference is the leading

consumer affairs and trading standards

event in Europe and hosted 120 exhibition

stands, interactive plenary sessions and mini

theatre sessions.

Over 2000 delegates attended the three-day

event and visitors to the ESC’s stand

included trading standards professionals,

senior leaders and decision makers from

local and national government - including

the Office of Fair Trading, LACORS, and LBRO

- as well as representatives from a range of

business and consumer organisations. In

addition to the information and advice

being sought from the ESC team, future

partnership and working opportunities were

discussed for the coming year.

The ESC had around 200 visitors to the

stand and the strong presence was further

cemented by the keynote welcome speech

delivered by director general Phil Buckle.

Also, the Council’s product safety manager

Steve Curtler presented the popular mini

theatre sessions on “Working with TSI for

safer electrical products”. These attracted

around 65 Trading Standard Officers. In

addition to this activity, ESC materials were

inserted in delegate briefcases and

advertisements were carried in the

conference promotional publications.

The event was a unique opportunity for the

Council to network and promote current

activities to large numbers of Trading

Standards professionals, including the

Trading Standards product recall interlink

microsite and The Safe Shoppers Guide which

has been produced to inform consumers

about the most common problems with

buying electrical products online. It also

provided the team with the opportunity to

raise awareness for the opening of this

year’s Fire Safety Fund which welcomes

applications from Trading Standards teams

UK-wide to apply for funding up to £5k to

support electrical fire prevention schemes at

local level.

Next year’s conference will take place in

Bournemouth at the Bournemouth

International Centre between 21-23 June

and will provide another opportunity

for the Council to tell the sector about

its work.

ESC PARTNERS WITH TRADING STANDARDS

Phil Buckle delivers the opening speech


Electric shock isnot the only dangerfrom electricity

Three separate incidents involving electrically-powered gates

tragically illustrate the dangers of electrical equipment in use.

To much of the general public, electric shockis the sole danger posed by electricity orelectrically-operated equipment. However,

many, especially children, don’t realise thatelectrical equipment can also pose a serious riskof physical injury when in use.

Children are more vulnerable than adults when exposedto electrical or electrically-driven mechanical equipment;they don’t see the dangers or they may be inquisitiveinto the workings of the equipment. Electrically-drivengates are one example, as tragically illustrated by threeseparate cases involving children who have died frommechanical movement of this type of gate.

The first accident involved a nine-year-old boy whosemother and sister watched as he was horrifically crushedby one of a pair of centrally-opening, wrought iron gatesdesigned and installed for security reasons at some flatsin Poole, Dorset.

The gates were attached on either side to brick pillars byhinges, which resulted in a gap of 160 mm existingbetween the gates and the pillars. To prevent accidents,the Automatic Entrance Systems Installers Federation(AESIF) recommends gaps associated with electric-powered gates should be no more than 100 mm. A gapof 100 mm will generally protect against penetration ofa head of a small child.

At the flats there was also a gate activation switchfitted inside the development, intended for providing asimple means of opening the gates to exit the flats.However, this could be reached by a personapproaching the gates externally, should they chose notto use the entry system provided on the outside.This effectively provided an unsafe means of activatingthe gates.

On the day of the accident the boy approached thegates from outside the flats, squeezed part of his bodythrough the 160 mm gap and reached out with hishand to operate the gate activation switch. Then as thegates opened inwards the 160 mm gap contracted, theboy became trapped and was crushed. He later diedfrom his injuries.

Three companies were later charged with contraveningSection 31 of the Health and Safety at Work Act 1974;two companies were acquitted, however the companythat manufactured and installed the gates was fined£80,000, with £40,000 costs.

Following the accident the Health and Safety Executive(HSE) in February 2010 issued a Safety Notice* toremind organisations or individuals involved in thedesign, construction, installation, maintenance and/orcommissioning of electrically-powered gates to thepotential safety risks to pedestrians.

feature



feature

r

Despite the HSE notice, two further fatal accidentsinvolving the mechanical movement of electrically-powered gates have occurred, just five days apart. Thetragic deaths of two girls aged five and six occurred inBridgend, South Wales and Manchester, respectively.

The two accidents, all though separate, had similarities:

• the gates were single electrically-powered;

• when opening, the gates slide along behind a wall(see Figure 1);

• the girls were pre-occupied playing games whenthe incident occurred;

• the gates were activated and slid into the openposition;

• the girls were trapped and died from their injuries.

The tragic accidents described above highlight the needto carry out risk assessments and comply with themeasures found, for example, in the MachineryDirective 2006/42/EC and BS EN 12453: 2001 Industrial,commercial and garage doors and gates. Safety in use ofpower operated doors – Requirements. Competentinstallers, such as those approved by AESIF, are vitalparts of the process where electrically-powered gatesare required.

To improve the safety measures of electrically-powered gate installations, there may be a need foradditional protective measures to those generally

incorporated in such systems, for example an audiblewarning when the gates are operating and/or anemergency stop button.

Indeed, Regulation 537.4.1.1 of BS 7671: 2008Requirements for electrical installations requires ameans to be provided for emergency switching of anypart of an electrical installation where it may benecessary to control the supply to remove anunexpected danger.

However, before a stop button is installed a riskassessment should be carried out to identify that anemergency switching arrangement does not introducefurther danger or interfere with the completeoperation necessary to remove danger (Regulation 537.4.1.4 refers).

The UK is not alone in automation accidents. AESIFhas reported that five fatalities involving automationoccurred in Spain in 2009 and data obtained from theUnited States Consumer Product Safety Commissionrevealed that every year 800 children are treated inhospital for injuries from automated gates.

In the light of this spate of tragic events, it is hopedthat electrical contractors, installers and otherinterested parties will have a critical look at allelectrically-operated gate installations they comeacross in the course of their work and, if possible, drawthe attention of the owners to any evident dangers tochildren.

“threecasesinvolvingchildrenwho havedied frommechanicalmovementof electricgates... ”


Figure 1: Guidance on gate safety

* HSE Bulletin No: FOD WSW 1-2010 (www.hse.gov.uk/safetybulletins/electricgates.htm)



feature

The Electrical Safety Council’s Grants

Scheme continues to support vulnerable

people in their local community, helping to

provide them with a safer home

environment.

During the last year, the Council enabled

486 grant beneficiaries across the UK to

have urgent small-scale electrical works

carried out by Care and Repair, the ESC’s

partnering home improvement agency.

In total, £79k was distributed between 11

local Care and Repair partners across the UK,

which was used to safeguard the health,

safety and wellbeing of vulnerable people in

emergencies and in situations that would

facilitate earlier discharge from hospital or

avoid admission. Work completed under the

scheme ranged from:

• urgent minor electrical works;

• electrical installation condition reporting;

and

• portable appliance testing.

Grants are awarded to members of the

community who are householders over 60

years of age, on means-tested benefit and

who cannot afford to carry out the

necessary electrical work in their home to

make it safer.

In the last year, Bristol Care and Repair

assisted 110 clients with electrical work

ranging from replacing failed light fittings

and dangerous sockets and repairing

electrical heating failures to upgrading

earthing and bonding and replacing

consumer units. The programme of works

also included installing residual current

device protection.

One of the many people the scheme was

able to assist in Bristol was an elderly

gentleman in his late 80s, who was in very

poor health and in receipt of state pension

with no savings. A fire in his kitchen had

occurred as a result of water ingress around

sockets close to the sink area, which caused

three appliances to ‘short out’ and ignite.

The gentleman was distressed as his wife

was due to be discharged from hospital and

no electrics worked in the kitchen because

of the fire. Our funding allowed for the

electrics to be repaired and enabled the

gentleman’s wife to come home from

hospital.

This case mirrored many others that the

scheme has helped since its inception and

highlights the positive effect it has had in

helping vulnerable people to make their

homes safer.

Lindsay Hay, the service manager at Bristol

Care & Repair said: “The scheme has been

extremely useful for our frontline advisors

who have been able to arrange emergency

works for clients having very little income or

savings, and without delays caused by

having to complete detailed funding

applications.”

Bristol Care & Repair also said that the

scheme has resulted in them giving a

greater focus to electrical safety issues in

their own training programmes that are

delivered to health and social care workers

in the area.

This year, £80k of grant funding has been

allocated and the Council will continue to

work in partnership, at local level, with

home improvement agencies..

HOMES MADE SAFE BY ESC GRANTS SCHEME

Grants are awarded

to members of the

community who are

householders over

60 years of age

Further details and information is available

on the website at www.esc.org.uk.


Have you everbeen asked...

Many owners of a touring caravan or motor caravan choose tostore their caravan at home, such as on a driveway, when not inuse for holidays. Some owners also connect their caravan’s230 V electrical installation to the electricity supply of theirhome to keep the caravan’s battery charged and to allow themains-voltage socket-outlets and lights in the caravan to be used.

However, in a high proportion of homes in the UK, a ProtectiveMultiple Earthing (PME) facility is used as the means of earthing forthe installation (TN-C-S system).

This leads to the question of whether it is permitted to earth theinstallation of a caravan to the PME facility when stored at home,given that regulation 9(4) of The Electricity Safety, Quality andContinuity Regulations 2002 (ESQCR), requires that: ‘The distributorshall not connect his combined neutral and protective conductor to anymetalwork in a caravan or boat.’

The question does not apply where the installation of the home isearthed to a means other than a PME facility – that is, to a separateprotective conductor of the supply, where provided (TN-S system), orto an installation earth electrode (TT system).

The reason for the requirement of regulation 9(4) is given in thePublication URN 02/1544 – Guidance on The Electricity Safety, Qualityand Continuity Regulations 2002, issued by Engineering Inspectorate ofthe former Department of Trade and Industry. ‘The particular risk atthese installations arises from the possibility of the supply neutralconductor becoming disconnected from earth, possibly causing themetalwork in the caravan or boat to rise to live potential (assuming thatthe caravan or boat does not benefit from an independent connectionwith earth). Persons entering or exiting the caravan or boat would thenbe at risk of electric shock.’

Connection of a caravan to the supply at home

Caravanners wishing to connect their caravan to the electrical supplyof their home usually do so by using the caravan’s 25 m ‘hook-up’ lead(see Figure 1) and connecting this to a socket-outlet of the home’sinstallation. This connection to the socket-outlet generally requires theuse of a 13 A to 16 A adaptor, such as that shown in Figure 2, as ahook-up lead is fitted with a 16 A BS EN 60309-2 plug as standard, tosuit the pitch socket outlets at caravan parks.

Earthing for the caravan

Whatever means is used to connect the caravan to the supply, a PMEearthing facility should not be used as the means of earthing for thecaravan. To do so would involve connecting the combined neutral andprotective (PEN) conductor of the supply to metalwork in the caravan,which is not permitted by ESQCR regulation 9(4), mentioned earlier.

Therefore, where a PME facility is used as the means of earthing forthe installation of the home, it is recommended that a socket-outletbe provided external to the building. The socket-outlet should besupplied through an RCD meeting the requirements of regulation415.1.1 for additional protection, and connected to an installationearth electrode meeting the requirements for a TT system. Figure 3shows a typical arrangement for doing this.

Figure 3: Typical supply and earthing arrangement for an externalsocket-outlet to supply a caravan at home

1) The socket-outlet should have a degree of protection (IP rating) suitable for its external

location.

2) The RCD should have a rated residual operating current (I∆n) not exceeding 30 mA and

an operating time not exceeding 40 ms at 5 I∆n, as required by Regulation 411.3.3.

3) The earth electrode should be selected and installed in accordance with Regulation

Group 542.2 and have no electrical connection with the PME earthing terminal. The

resistance of the earth electrode should be as low as practicable and not exceed

1667 Ω. A value exceeding 200 Ω may not be stable. BS 7671 Table 41.5 refers.

4) The socket-outlet should not be installed inside the building, as this may result in

equipment in the home being plugged into the socket outlet, which could in turn

result in exposed-conductive-parts that are connected to different earthing systems

being simultaneously accessible, contrary to the requirement of Regulation 411.3.1.1.

The arrangement in Figure 3 reflects the requirement of Regulation708.553.1.14 for the earthing of a caravan pitch socket-outlet at acaravan park. The regulation requires that the socket-outlet shall notbe connected to any PEN conductor of the electricity supply, but shallbe connected to an earth electrode, and that the requirements ofRegulation 411.5 for a TT system shall be met.

Essentially the same requirement is found in EngineeringRecommendation G12/3 – Requirements for the application of PME to low voltage networks, issued by the Energy Networks Association.Clause 6.2.6 states that ‘Supplies to caravans and boats should be two wire phase [line] and neutral supplied through an RCD which must be supplied by the site owner. An independent earth electrode is required …’

Is it permitted to earth the electricalinstallation of a caravan to a PMEearthing facility when kept at home ?

Figure 2: Typical 13 A - 16 A adaptor

Figure 1: Caravanhook-up lead


technical



technical

In light of the recent warning to the UK

electrical industry to be vigilant for

recent batches of 'Atlas Kablo' branded

cable, Jeremy Hodge of BASEC

discusses the importance of taking all

necessary precautions to check your

cables are safe

The British Approvals Service for Cables (BASEC) has advised theelectrical sector to be vigilant for recent batches of Atlas Kablo brandedcable that has been found to have insufficient copper, leading toexcessive conductor resistance. As soon as the problem was brought toBASEC's attention by a vigilant distributor, Atlas Kablo had its BASEClicence suspended due to the scale and severity of the problem (thelicence has subsequently been cancelled, see box).

The manufacturer was required by BASEC to investigate, tocommunicate with customers and to assist the market in locating andrecovering affected product for scrapping. A communication was sentto distributors, buying groups, wholesalers and contractors to ensurethey checked and quarantined affected cable.

Cable from manufacturers holding a BASEC licence is regularly retestedwith a range of assessments to ensure conformity. Unfortunately,suspect cable products can often be found in the UK marketplace andhistorically these have not been subject to the same level of scrutiny oraction. Now, however, organisations such as BASEC and the ApprovedCables Initiative are active in responding to leads from installers andtraders, testing cable, identifying sources, and providing warnings to themarket. All public warnings and further advice can be found on theBASEC and Approved Cables Initiative websites www.basec.org.uk andwww.aci.org.uk.

Electrical contractors, specifiers and electricians who purchase andinstall cable have a responsibility to ensure that the cable they specifymeets British and/or European standards to ensure compliance withthe Wiring Regulations. In some cases markings on the cable sheath canbe misleading, or even make false claims of compliance with aparticular standard. Always look for a manufacturer's mark that yourecognise. For peace of mind, you should also insist on an independentthird-party approved cable with either a BASEC, HAR or equivalentmark. It is also important to specify on your order the British Standard(BS) number the cable must comply with.

Installers who are concerned that affected cable may have been usedshould ensure they check that the necessary electrical installation

verification tests have been performed by a qualified and competentelectrician. Any performance concerns following these tests should beinvestigated to ensure circuits are safe or need protection enhancementor cables replaced.

We would advise that you keep records of all purchases, including reelends with batch markings, receipts from distributors and sales recordson your computer system. If you are unsure of the cable and have anyscrap lengths, these can be sent to the BASEC for checking and testing.

Jeremy Hodge is chief executive of the British Approvals Service forCables (BASEC).

Further information and guidance may be obtained from BASEC [email protected] Tel: 01908 267300, or at www.basec.org.uk

Spotlight on…BASEC and cable safety

Atlas Kablo licence cancelled

On Monday 17 May 2010, BASEC suspended the product

certification licence of Atlas Kablo, of Denezli, Turkey. The

licence is now cancelled and the company no longer holds a

BASEC product certification licence.

As a consequence, the use of the BASEC registered

trademarks in connection with cable produced by Atlas Kablo

is no longer authorised and cable produced by Atlas Kablo

bearing the BASEC registered trademarks should not be sold.

The reason for the suspension was a serious decline in quality

across the company’s range of products. Affected cable has

excessive conductor resistance (insufficient copper). BASEC

advises that affected cable should not be sold or installed, and

to seek advice if it has been installed.Atlas Kablo has notified

its customers, issued a letter of guidance and posted a list of

affected batches of cable on the Atlas Kablo website

(www.atlaskablo.com).

The quantity of cable involved is 11 million metres, and

identified batches are production with a “2010”

manufacturing date. Cable traders, wholesalers and

contractors should check what cable they have in stock,

quarantine affected cable and notify their supplier about

recovery, or contact Atlas Kablo direct.



technical

We report on phase three of the Council’s study into

RCD performance

Phase three of the Council’s research into the reliability of residualcurrent devices (RCDs) in domestic premises got underway last year.

The research, commissioned by the Council, was carried out by ERATechnology with the principal aim of investigating abnormal factorsthat could potentially affect the operation of RCDs, compare theperformance of voltage-dependent and voltage-independent RCDs andinvestigate alternative technologies for auto-testing of RCDs. Afterconsultation with the Council’s RCD Research Steering Committee,comprising representatives from ECA, BEAMA, Schneider Electric andGreenbrook, the test programme was set as follows:

• determine the adequacy of RCD main contacts under fault currentconditions

• explore the circuit conditions that could affect the operation ofRCDs, including the effects from fault conditions

• determine the influence of connected loads, in particular theinfluence of capacitive loads

• investigate whether equivalent technologies exist that can be reliedupon without the need for periodic testing by users.

The project, which is now nearing completion, has involved acombination of desktop research and, where appropriate, laboratorytesting using simulated installation conditions. Although the final reporthas been drafted, there are still some points that require furtherdiscussion and deliberation with the RCD Steering Committee and RCDtest instrument manufacturers. Once these points have been finalised,the ESC hopes to include a more detailed summary of the results fromthe research in the next issue of Switched On. In the meantime, someof the main findings from the research to date are as follows:

RCD main contacts

The RCD product standards BS EN 61008-1 and BS EN 61009-1 requirea test current of 500 A or 10 I∆n (whichever the greater) for checkingadequacy of RCD main contacts for breaking fault currents. However,previous research shows that prospective earth fault currents upwardsof 1000 A are not uncommon in domestic installations.

To simulate the adequacy of RCD contacts breaking earth fault currentsin line with those found in typical domestic installations, it was decidedthat the laboratory testing should apply a test current of both 500 A

and 1000 A for comparative purposes. The results of the testing showedthat degradation of the RCD main contacts can occur at both 500 Aand at 1000 A, as shown in Figures 1 and 2.

The damage shown in both Figures 1 and 2 is commensurate withexpected results and is within acceptable limits, according to the RCDResearch Steering Committee.

Circuit conditions that could affect RCD operation

The research involved carrying out a desktop exercise to investigatewhat installation conditions could in theory lead to malfunction of theRCD. These theories were then replicated and simulated in laboratorytests. The main conclusions of the findings are as follows:

Neutral-to-earth faults

An RCD will detect and operate in the presence of a neutral-to-earthfault in the following circumstances:

• where there is a neutral-to-earth voltage, caused by the voltagedrop along the neutral conductor, or

• where there is a load connected, part of the load current thenflows back to the source of supply via the earth return thusoperating the RCD.

However, in an installation forming part of a TT system, a highimpedance earth combined with a neutral-to-earth fault can causeRCDs (RCCBs and RCBOs) not to operate. This is because if a line-to-earth fault occurs in an installation having a pre-existing neutral-to-earth fault the fault current will split between the neutral and earth. Ifthe earth path is of sufficiently high impedance the portion of currentflowing down it may not be enough to cause an imbalance and tocause the RCD to operate.

Open-circuit PEN conductors

In an installation forming part of a TN-C-S system with an open-circuitPEN conductor, the circumstances of whether the RCD will operatedepend on its type.With voltage-independent RCDs, an open-circuitPEN conductor should not affect the operation of the RCD under line-to-earth fault conditions, as long as there is a sufficiently lowimpedance path back to the source of supply. However, under the sameconditions, but with a voltage-dependent RCD, the resulting line-to-earth voltage during the earth fault may not be sufficient for theamplification circuit to operate the RCD.

Influence of connected loads

The research indicated that for circuits containing capacitance, such asfor motor starting, filters for IT equipment or EMC requirements, RCDtrip times shown on the oscilloscope can be shorter or longer than thetime recorded on the RCD test instrument. This disparity betweenmeasurements was more significant depending on what make andmodel of RCD test instrument was used.

To this end, the Council is in the process of discussing these resultswith manufacturers of RCD test instruments. Once the discussions arecomplete, a report of the research findings will be published on theESC’s website www.esc.org.uk and a more comprehensive article willbe developed for Switched On.

Progress of investigation into in-service reliability of RCDs

Figure 2: Moving and fixed contacts

after 1000 A test

Figure 1: Fixed contact and conductor

after 500 A test



technical

For either a new installation, or an alteration or addition to anexisting installation, Part 3 of BS 7671 requires an assessment tobe made of the general characteristics, including the maximumdemand.These characteristics are to be taken into account in thechoice of protective measures (Part 4) and in the selection anderection of equipment for the installation (Part 5).

With the exception of the maximum demand, this article givesguidance on assessing the general characteristics for the electricalinstallation of an individual dwelling (house, bungalow or flat).Guidance on assessing the maximum demand for a dwelling will begiven in a future issue of Switched On.

General

Regulation 300.1 requires the following characteristics of an installationbe assessed, in accordance with the Chapters indicated.

• The purpose of the installation, its general structure and itssupplies (Chapter 31)

• The external influences to which it is to be exposed (Chapter 32)

• The compatibility of the electrical equipment (Chapter 33)

• Its maintainability (Chapter 34)

• Recognised safety services (Chapter 35)

• Assessment for continuity of service (Chapter 36)

Purpose, structure and supplies (Chapter 31)

Chapter 31 identifies particular characteristics relating to the purpose,structure and supplies of the installation that must be determined andtaken into account. An abbreviated checklist of these characteristics isgiven in Table 1.

Information about items b), c) and d) of Table 1 for the main incomingsupply to an installation can be obtained from the electricitydistributor. Some distributors make this information available bypublishing notes of guidance giving:

• the number of phases (generally one for a single dwelling)

• the frequency (generally 50 Hz)

• the nominal voltage (generally 230 V line-to-earth)

• the maximum prospective short-circuit current at the supplyterminals

• the earth fault loop impedance of that part of the systemexternal to the installation (Ze)

• the type and rating of the distributor's protective device ordevices nearest to the supply terminals

• the type of earthing arrangement applicable to the connection (TN-S, TN-C-S or TT).

External influences (Chapter 32)

Part 2 (definitions) of BS 7671 defines an external influence as: “Anyinfluence external to an electrical installation which affects the designand safe operation of that installation.”

The electrical installation designer must assess the external influencesto which each part of the installation is likely to be exposed duringinstallation, use and maintenance. The external influences must betaken into account in the choice of measures of protection for safetyand selection and erection of equipment for the installation.(Regulation Group 512.2 and Section 522 refer.)

Examples of external influences include ambient temperature, presenceof water and high humidity, impact and solar radiation. Appendix 5 ofBS 7671 gives a comprehensive list of external influences, some ofwhich will apply to the installation in a dwelling.

A bathroom or shower room is a location in a dwelling where thepresence of water and high humidity needs particular consideration. InSection 701 of BS 7671 – Locations containing a bath or shower –Regulation 701.512.2 specifies the minimum degrees of protection(IP ratings) for electrical equipment, including wiring systems, to beinstalled in each of zones 0, 1 and 2 of the location.

Compatibility of the electrical equipment (Chapter 33)

Regulation 331.1 requires an assessment to be made of anycharacteristics of the equipment of an installation likely to haveharmful effects on other equipment or services, or be harmfullyaffected by them, or impair the supply. Examples of such characteristics(listed in Regulation 331.1) include transient overvoltages,undervoltages and excessive protective conductor currents.

For an installation in a dwelling, the main practical considerationregarding compatibility is to follow manufacturers’ instructions inapplying and installing equipment.

For example, where lighting is to be controlled by a dimmer, theluminaires must be suitable for this purpose. Certain types of luminaire,such as fluorescent and extra-low voltage, require special controlgear to

Assessing the general characterisics of adomestic electrical installation

Table 1: Checklist of characteristics relating to purpose, structureand supplies

a) The maximum demand (to be covered in a future issue of Switched On)

b) The number and type of live conductors (generally one line and a neutral)

c) The type of earthing arrangement (generally TN-S, TN-C-S or TT)

d) The nature of the supply or supplies, including:

(i) nominal voltage(s) and characteristics, including harmonic distortion

(ii) nature of current (ac or dc) and frequency

(iii) prospective short-circuit current at the origin of the installation

(iv) earth fault loop impedance at the origin (Ze)

(v) suitability of the installation for its required purposes, including

maximum demand

(vi) type and rating of the overcurrent protective device at the origin

(supply main fuse)

Note: The characteristics in (a), (b), (c) and (d) must be ascertained for an

external supply and determined for a private source, such as a generator. This

applies equally to main supplies, standby supplies and supplies for safety services.


technical

achieve dimming. Also, the dimmer must be adequately rated for theload current and for the type of load (resistive or inductive).

Maintainability (Chapter 34)

Regulation 341.1 requires an assessment to be made of the frequencyand quality of maintenance that an installation can reasonably beexpected to receive during its intended life.

The reason for the assessment is to allow the equipment andprotective measures for the installation to be chosen and installed sothat, for the intended life of the installation:

• the periodic inspection, testing, maintenance and repair likely tobe needed can be readily and safely carried out;

• the protective measures must not diminish for safety to remaineffective;

• the reliability of equipment for proper functioning is sustained.

Wherever practicable, the wiring and other equipment of the electricalinstallation in a dwelling should be of a type requiring little or nomaintenance.

Where maintenance is necessary, the equipment concerned should beselected and installed to make it as simple and safe as possible tomaintain, especially where it may be worked on by the householder. Forexample, luminaires should not be positioned where it would bedifficult to gain access for re-lamping.

Safety services (Chapter 35)

The only safety services likely to be required in a dwelling are a firealarm and fire detection system (generally smoke alarms and possibly

some heat alarms) and,exceptionally, anemergency lightingsystem.

Any requirement toprovide either of thesein a dwelling will befound in guidance thatsupports nationalbuilding regulations. Thisguidance is given inApproved Documents inEngland and Wales, theTechnical Standards thatsupport the relevantbuilding regulations inScotland, and in Technical Booklets in Northern Ireland.

Continuity of service (Chapter 36)

Continuity of service is not usually a major issue for the electricalinstallation of a dwelling but it needs to be considered nevertheless.The one and only example that Chapter 36 gives where continuity ofservice may be considered necessary during the lifecycle of aninstallation is for a life support system, which is not found in mostdwellings.

Where continuity of service is an issue for any circuit of the installation,the characteristics listed in Regulation 361.1 should be considered.These include (amongst others) the number of circuits, the use ofmonitoring equipment, and multiple power supplies.

New research for the Electrical Safety Council has highlighted the riskspeople are exposed to from electricity1. It demonstrates the high levelof risk to tenants in private properties, and where the threat of injurylies. This new research gives a clear picture of the danger to the UKpopulation from both electrical installations and products.

Worryingly, while only 14% of the population live in privately rentedaccommodation2, some 20% of people who experienced electricshocks live in privately rented homes. This suggests that private tenantsare at disproportionately high risk of electric shock. Previous studiesconducted on behalf of the Electrical Safety Council have indicated thatprivately rented properties are among the least likely to have RCDprotection in the consumer unit, with 52% left unprotected3.

The survey asked people what had caused their injuries. The twobiggest causes were using faulty appliances (21%) and carrying outrepairs or maintenance without having turned off the electricity at themains (20%). This highlights both the need to ensure that electricalproducts are maintained in good working order, and the importance ofhaving repairs carried out by someone who knows how to work safelyon electrical products and fixed wiring.

The study also revealed that 64% of those injured by electric shockacross all age groups were men. However, this varies greatly with age:of those aged 55+ who reported having an electrical shock, 73% ofthose injured were men, whereas in the 18-24 age range, equalamounts of men and women reported being injured.

Electrical installations and lighting remain a major contributor toelectric shocks. Between them they accounted for two fifths (43%) ofall electric shock injuries.

Nearly a quarter (23%) of people who had had an electric shock in thelast five years reported being burnt as a result. Over one in six of the23% were left scarred by the burn ie 4% of the total sample.

This work will continue to inform the ESC’s campaigning activity. As theCouncil gets more clarity on which groups are most at risk from injuryfrom contact with an electric current, it can focus its campaigning workand help those people most at risk to protect themselves from danger.

1 All data unless otherwise indicated from Ipsos Mori: 1024 adults aged 18-65 inGreat Britain who have personally experienced an electric shock thatresulted in injury while at home or in the garden in the past five years,interviewed via Ipsos online panel 25 June - 2 July 2010

2 http://www.communities.gov.uk/documents/statistics/pdf/1346249.pdf, pp11 (England data)

3 Data supplied by BRE (formerly the BuildingResearch Establishment), used to informthe English Housing Survey

Private tenants at increased risk of electric shock




technical

We investigate the issues of overloading four-way

extension leads fitted with a 13 A BS 1363 fuse

As part of the Council’s electrical product safety screening programme,and following several reports of fires where the source of ignition wasattributed to a four-way extension lead, the ESC decided to investigateand replicate the effects of overloading of these products.

Also, the Council’s latest research into electrical product riskcategorisation indicated that extension leads are a high priority forfurther investigation and for evaluation regarding safety andcompliance with product standards.

Use and misuse

Extension leads are used in most households as a temporary meansfor supplying equipment for purposes such as DIY and gardening. Theyare also used as a more permanent means for supplying severalelectrical appliances in households, usually because the number offixed socket-outlets is insufficient. In most cases, extension leads areused either for short periods, as would be the case for DIY orgardening work, or for longer periods to supply appliances operating atrelatively low currents.

In some instances, however, several high current-using appliances, suchas electric heaters, are plugged into an extension leads or severalextension leads are coupled together with numerous electrical itemsplugged into the available outlets. The consequences of such actionscan be that the total current flowing through one or more extensionleads exceeds the maximum rating of 13 A (or 5 A for lower ratedextension sets).

The overloading of extension leads is arguably a foreseeable conditiondespite the presence of permanent marking on the product, warningagainst exceeding the maximum rated current. It is also reasonable tosuggest that most members of the general public would, if asked, thinkthat the 13 A fuse fitted in the supply plug will provide overloadprotection in the event of them unwittingly exceeding the maximumcurrent rating. However, this is simply not the case.

Product testing

The national standard for extension leads, BS 1363-2: 1995, specifiesa maximum ‘continuous use’ rating of 13 A for the fitted plug andsocket-outlet. The test current is set marginally above this at 14 A fortype-testing, to determine compliance with the product standard.Standard BS 1362: 1973, covering the fuse link, requires the fuse tooperate at 1.9 times rated current (that is 24.7 A) within 30 minutes,and also that the fuse shall have a non-fusing current of 1.6 timesrated current (that is 20.8 A).

It is therefore possible for an extension lead to carry a total current of20 A for an indefinite period. While this may not be a commonsituation, the product testing undertaken was to determine whetherit is possible to overload extension leads such that they might pose afire hazard.

Investigation into overloading of four-way extension leads

After consideration of various other factors that could

affect safety, the test programme was set as follows:

• Visual assessment of fitted plug (under BS 1363-1)

• Visual inspection of fuse including counterfeit indications

• Measurement of supply cord conductor cross-sectional area

• 5000 insertions/withdrawals, on one socket from each type

• Post endurance test assessments, including shutteroperation, access to live parts, insulation resistance andelectric strength

• Temperature rise test at 20 A, the total load being dividedequally between two of the possible four socket-outlets.Minimum test duration being time to operation of the fusewith maximum duration of four hours.

Seven samples were tested: six were randomly selected andpurchased and one sample was tested that had been in use atthe Council’s office.


Product testing results

All of the fitted plugs satisfied the visual assessment under BS 1363-1.The fuse in each fitted plug appeared genuine and contained theexpected quantity of sand filler (used for assisting arc extinction).

The cross-sectional area of flexible cord conductors for each samplewas marked as 3 x 1.25 mm2, which was verified by measurementand was correct in each case.

Each sample passed the 5000 insertion endurance test with noevidence of damage and the socket-outlet shutters continued toshield live parts.

All except one of the samples passed the insulation resistancetesting. The exception was the sample that incorporated RCDprotection where damage after the overload test prevented theapplication of the 6 kV insulation resistance test.

As expected, it was the results of the overload and temperature risetest that gave the most concern. In all but one case, the supply leadplug on each sample showed varying states of overheating damageand enclosure deformation. The accessible surface of the fitted plug

was measured for five of the seven samples. The lowest recordedtemperature was 84.5oC and the highest was 200oC. This highesttemperature softened the plug body leaving the line conductor pinin the mains socket-outlet after the test, as depicted in Figure 1.Significant damage was also observed for one other sample wherethe accessible surface of the plug reached 153.4oC, as depicted inFigure 2.

Conclusions and next steps

It is possible and arguably foreseeable to overload extension leads,resulting in hazardous conditions, and that the fitted supply plugappears to be the weakest component part.

The limited insertion endurance test of 5000 operations was anattempt to simulate poor contact within the four-way extensionbut this did not highlight any such concerns for the limited samplesize of seven products.

The accessible surface temperature of two samples reached 153oCand 200oC, which was sufficiently high to cause damage to thesupply plug body, leading to an electric shock hazard. This wasespecially apparent during the testing of the sample where the lineconductor pin became detached from the plug and remained in thesocket-outlet.

For the samples where damage to the plug was observed, anobvious odour was present after about 20 minutes into theoverloading. This would be likely to provide sufficient time for theuser to take action, if someone was in the house and was awake atthe time.

The maximum temperatures of 153oC and 200oC are also slightlybelow the ignition temperature of most furnishings and paper thatmight be in close proximity to the fitted plug. This leads to thequestion whether the reported fire incidents are more likely tohave resulted from poor contacts within the socket-outlets of thefour-way extension block, rather than from overloading. While thisis feasible, it is difficult to fully support this supposition with such asmall sample size. To this end, the Council will continue to liaisewith Trading Standards Officers and Fire and Rescue Services withthe aim of collating more detailed evidence from incidentsinvolving four-way extension leads.

Misuse of electrical products is outside the scope of the ElectricalEquipment (Safety) Regulations, so further discussion needs to takeplace to determine whether foreseeable conditions of overloadingof extension leads constitutes a required change in the regulationsand product standards. The Council will raise this issue through itsrepresentation on various product standard committees.

Nevertheless, the findings of the research reinforces the need toprovide consumer advice about the dangers of overloadingextension leads with further suggestions for keeping the areaaround the extension set free from dust and other combustiblematerials. We will also encourage users of extension leads to carryout regular visual checks to look for signs of overheating damageat the plug and socket-outlets and to do routine maintenanceoperations on the supply plug, flexible lead and four-gang socket-outlets.

A copy of the test report is available in the ‘business and community’section of the Council’s website www.esc.org.uk


technical

Figure 1: Line conductor pin stuck in socket-outlet

Figure 2: Damage to supply plug exposing line

conductor pin


20

Research carried out by the Council shows how the EU

Injury Database played a vital part for categorising the

risks associated with electrical consumer products.

Although the UK has a fair record of electrical safety, someone diesevery week in an electrical accident at home. Further, there are anestimated 4,000 injuries and 8,000 fires in people’s homes causedby an electrical fault every year and nearly 113,000 estimatedinjuries are caused by using electrical products without due care.

To help the Council achieve the greatest impact and benefit forconsumers, it carried out a risk categorisation exercise for electricalconsumer products. This involved analysing data from sources, suchas EU RAPEX, UK fire statistics, Trading Standards, newspaperclippings and from consumer incidents reported on the Council’swebsite (www.esc.org.uk ). However, to produce risk categoriesthat considered all contributing factors, the ESC needed to includea factor for injuries caused by using electrical products.

Injury data

The UK system for collecting injury data was, until 2002, theHome and Leisure Accident Surveillance Systems. But,unfortunately, in 2002 the Government ceased to collect this datafor the UK. Since then the range of electrical consumer productsavailable in the UK has increased year on year. The vast majorityare now manufactured in the Far East and imported, and there hasbeen a rapid growth in the purchase of electrical products over theinternet. Hence the HLASS database is now of limited value inassessing injury rates and trends.

To this end, the Council turned to the EU Injury Database. Injurydata was analysed from a sample of 84 hospitals from eightEuropean Countries between the years 2005 and 2007. Thisrepresented a good cross-section of EU countries and cultures fromwhich detailed analysis was carried out and estimates were madeby extrapolating into 27 EU member countries.

Analysis of the 2005-2007 injury data indicated an estimated1,212,000 injuries being attributed to electrical products or 2.96%of the total cases. The vast majority of these cases are due tophysical injury and are not directly attributed to the electricalintegrity of the products concerned. The breakdown of the resultsfor electrical products is shown in Figure 1.

Other contributing factors

Evaluation of electrical consumer products notified as being unsafeunder RAPEX, indicates that in most cases the product standards

written to support the Low Voltage Directive are either notunderstood or not properly followed. However, the fact thatproducts do not pose an electric shock risk does not mean thatthey do not pose a safety risk. For example, health and beautyproducts that may be used close to the body that are either sharpor emit heat may pose a risk to consumers or vulnerable users.

Another key factor is unnecessary child appeal built into the designof products that could be a hazard to children eg kitchen andcooking appliances shaped to look like an animal. Such productsshould be supported by an appropriate risk assessment and riskmanagement process.

In terms of domestic fires in the UK, the general trend is that thenumber of electrically-related fires is decreasing. However, thenumber of fires due to electrical consumer products accounted forover 90% of all fires having an electrical origin in the 2007 UK firestatistics.

Conclusions

Taking all relevant data sources into account, the following is alist of products registered as high priority for further researchand evaluation regarding safety and compliance. These productswill also be considered in the future safety screeningprogramme conducted by the Council:

• Lighting chains • Night lights • Hair straighteners /curlingdevices • Deep fat fryers • AC/DC adapters for toys • Extension leads • Kitchen and cooking devices with play value • Residual current devices (RCDs)

Additionally, the Council continues to lobby the government todevelop and implement an appropriate database to collectinjury data, as required by the EU.

Exploring the EU Injury Database (IDB) for consumerproduct risk categorisation

All the previous issues of Switched On are available to read or

download from the ‘Business & Community’ section of our website.BACK ISSUES OF SWITCHED ON

Figure 1: Breakdown of electrically-relatedinjuries per product category


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