DIY UK centre selected stores B and Q, MFI furniture, books
and information, plumbing and electrical DIY tools to make your do it yourself
experience easy to hand
Welcome to 24-7 Electrical, the
on-line shop where you can buy the largest
selection of quality electrical goods in the
country, ranging from telephones to the highest
technology TVs. Our prices are the lowest
possible, saving 20-30% off typical High
Street prices. All our products are UK spec, and
we do not sell any grey imports.
I. Introduction
Electrical Hazards, risks of injury or
death arising from exposure to electricity.
Electricity is essential to daily life, providing
heat and light and powering appliances in homes
and factories. It must, however, be treated with
great care, because the consequences of an
electrical fault can be serious and sometimes
fatal. Generally voltages greater than 50 volts
can present a serious hazard and currents of more
than about 50 milliamps flowing through the human
body can lead to death by electrocution.
A shock occurs when a "live" part of some device
is touched, so that current passes through the
body. Its severity depends on many factors,
including the body's conductivity (the ease with
which electricity passes through it). The
conductivity is usually small, but can be
increased if the body or clothing is wet. The risk
of injury also increases according to the size of
the voltage or current, or the duration of
contact. There is a risk of electrocution (death
by electric shock) if current passes across the
heart. For example, if one foot is touching wet
ground, the risk is greater if the arm on the
opposite side touches a high-voltage source than
it would be if the arm on the same side did so.
Current passing into the body generates heat,
which burns the tissue. Electricity can also
present less direct risks. Burns are caused when
hot surfaces on electrical appliances are touched,
and some appliances present a risk of injury from
moving parts. Fires are caused when wires or
cables overheat, melting their covering of
insulation and setting fire to any combustible
material nearby.
Official figures show that 31 people died in
electric current accidents in homes in England and
Wales in 1992, and around 13,000 people were
injured in electrical accidents in and around the
home. Most were males between 15 and 64 years of
age, carrying out do-it-yourself and maintenance
work. Several deaths were caused by people
touching the live end of a cable cut by an
electric lawnmower.
Electrical faults in the home cause around 25,000
fires each year, killing or injuring over 2,000
people.
Most countries have detailed regulations governing
the standards to which electrical installations
must conform. In the United Kingdom the Wiring
Regulations (BS 7671), produced by the Institution
of Electrical Engineers (IEE) and the
British Standards Institution (BSI), prescribe
the wiring standards to be adopted. The Electrical
Contractors Association (ECA) and the National
Inspection Council for Electrical Installation
Contracting (NICEIC) require their members to
observe these requirements to minimize any danger.
In Britain, domestic electrical products must
satisfy the requirements of the Electrical
Equipment (Safety) Regulations (1994), which were
made under the Consumer Protection Act (1987), and
implement the Low Voltage Directive (73/23/EEC) of
the European Union (EU). The technical
interpretation of the legal requirements is
provided by a standard for electrical products, EN
60 335, which is harmonized among EU member
countries, and manufacturers are encouraged to
seek independent third-party quality assurance for
their products, such as that provided by the BSI
and BEAB (British Electrotechnical Approvals
Board).
In Britain, following a campaign by RoSPA, the
Royal Society for the Prevention of Accidents, all
domestic electrical appliances must now be
supplied complete with a fitted plug. A
non-rewirable or moulded plug is preferred, which
must be approved by a recognized body such as BSI.
In the home, appliances, plugs, and cables must be
checked for damage regularly and replaced or
repaired by an expert when necessary. Electrical
wiring should be inspected every five years by
experts, such as those recognized by the ECA and
the NICEIC.
Children must be warned to keep away from
railways, electricity sub-stations, and factories,
and fishing-rods, especially those made of carbon
fibre, and kites must not be used near overhead
power lines.
Anyone using electrical equipment out of doors
should ensure that the supply is protected by an
RCD (residual current device), which detects any
current to earth and so will protect the user
against the danger of serious electric shock by
disconnecting the supply in the event of a fault
occurring.
In the home, fuses, which are a rather crude
method of protecting the distribution system
against excessive current, have largely been
replaced by the more precise MCB (miniature
circuit-breaker), and RCDs are now usually
incorporated to provide added safety from the
danger of electric shock.
Contributed by:
David Jenkins, B.A., M.Phil.(Eng.), DCA, FITSA
Product Safety Adviser to the Royal Society for
the Prevention of Accidents. Chairman of Consumer
Safety International. Author of Enforcing
Product Safety Law in the EEC. Editor of
Product Safety Enforcement News.
