SAFed Health and Safety Passport Scheme

Module 11 — Electricity in the Workplace

11.1            Introduction

This document forms one of a series of modules on various health and safety subjects that comprise the examinable material considered necessary for the award of the SAFed Health and Safety Passport.

When you have studied this module you should have acquired sufficient knowledge to be able to complete the questions detailed at the end of the module.  Upon satisfactory completion of all modules, you will be eligible to undertake the final assessment for the award of the SAFed Health and Safety Passport.

The SAFed Health and Safety Passport is issued to Engineer Surveyors by the Health and Safety Manager of their employing company upon satisfactory completion of the Safety Passport final assessment.

The award of the SAFed Health and Safety Passport provides evidence that the holder of the Passport has the appropriate knowledge and awareness in health and safety matters considered necessary for an Engineer Surveyor to undertake the duties for which they are authorised by their employing company.

The passport is valid for a maximum of three years.

11.2     Key Objectives

Having read this module you should be aware of:

·                     The legal requirement regarding electricity at work within your own company and if applicable, the site at which you are working at the time.

·                     The potential dangers of electricity, and how to avoid them.

11.3     Legal Commentary

The Health and Safety laws, which cover this module, are:

·                     The Health and Safety at Work etc. Act 1974

·                     The Electricity at Work Regulations 1989

·                     The Management of Health and Safety at Work Regulations 1999

·                     The Low Voltage Electrical Equipment (Safety) Regulations 1989

·                     The Provision and Use of Work Regulations 1998

11.4             Discussion

Electrical equipment is in use in almost every workplace.  Electricity has certain dangers that are not necessarily present with other equipment.  As a result there is a particular need to ensure the safety of all people that use electrical equipment as part of their work or who could be exposed to danger by faults in electrical equipment.

The term “portable” is not determined by the size of the equipment but, quite simply, by the means by which it is connected to the mains power supply.  Portable electrical equipment is connected to the fixed wiring by means of a plug and cable.

Electricity poses the following dangers:

·         Shock

·         Burns

·         Fire

·         Arcing

·         Explosion

Many people have had an electric shock at some time or another without lasting injury but this does not demonstrate immunity, merely the unpredictable nature of the risk.  Slightly different circumstances could have resulted in death.  If the victims of electric shock do not die, they usually recover very quickly unless there are other injuries for example burns, muscle damage or injuries from falling as a result of the shock.

The danger of serious injury or death is increased if the resistance through the body of the person touching a live conductor is lowered.  In general this would occur if the point of contact with the conductor or the ground, on which the person is standing, were wet.  Thus electrical equipment should never be used or switched on or off by someone with wet hands or in a damp environment.  Some, but by no means all, electrical equipment is specially constructed to cope with wet or damp environments.  If you have any doubt, do not use it in this type of environment.

The nature and severity of injuries from electric shock depend on;

·         The magnitude of the current

·         The duration of the shock

·         The path of the current through the body

·         The frequency of the electricity supply (50Hz)

If an electric current passes through the body it will generate heat.  The main problem is that the burns caused by the passage of the current will not just occur at the surface of the body.  The burns caused by electricity can be very severe and are often within the body.  The burns at the surface and at the point of entry and exit of the current flow tend to be deep and take a long time to heal.

When excessive current flows in an item of electrical equipment or a cable, heat will be generated.  The cause of too much current flow may be a fault condition or because the wrong cable is being used which cannot carry the load.  The result of this excess heat can often be the cause of a fire.  Many fires in industry and in the home are caused by electrical faults.

Arcing, overheating and, in some cases, electrical leakage can cause fire or explosion by igniting flammable materials.  This can cause death, injury and considerable financial loss.  The intense ultraviolet radiation from an electric arc can also cause damage to eyes.

[Note: The domestic supply of 230v / 50Hz should always be considered fatal]

 

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11.5            Legislation and Records

In a workplace the employer has a general duty, given by the Health and Safety at Work, etc Act 1974 to ensure the safety of employees and those affected by the work.  The dangers must therefore be identified and complying with the requirements of the Management of Health and Safety at Work Regulations 1999 to undertake risk assessments does this.  Where any equipment is used, and this certainly includes electrical equipment, there is a requirement under the Provision and Use of Work Equipment Regulations 1998 to ensure that it is suitable for the purpose for which it is provided or used.  All of this legislation is quite general and covers all equipment in the workplace, it is not specific to electrical equipment.  This responsibility is made more specific in Great Britain under the Electricity at Work Regulations 1989.  These require precautions to be taken against the risk of death or injury from electricity during work at or near electrical systems (electrical installations and equipment).

The regulations apply to employers, employees (including trainees) and the self-employed.  They may all become duty holders; i.e. they have a responsibility to comply with the regulations where matters are within their control.

BS7671 ‘Requirements for electrical installations’, although non-statutory, is a code of good engineering practice and makes requirements for systems and equipment to be designed, constructed and installed so that they can be used safely.

There is no specific requirement for records to be held in any legislation.  However, it is important to know which equipment has been tested and what the results are.  This information can help to spot problems before the equipment causes damage or injury, or fails to work.  In addition it is important to be able to prove that the checks, inspections and tests that are necessary to ensure that the electrical equipment remains safe, have actually been done.  Thus it is important to ensure that records of the inspections and tests are taken.  This will usually require all electrical equipment to be uniquely identifiable to link the records with specific items of equipment.  Frequencies are determined by risk assessment, however a general rule of thumb for fixed wiring installations would be six monthly to five years depending on its use.  Portable appliance testing (PAT), depends on the risk factor, and can be anything from every three months to every four years.  All portable appliances should have a label attached to indicate that they have been satisfactorily tested.

11.6     Safe Working Practices

Most accidents occur because people are working on or near equipment that is:

·         Thought to be dead but which is live;

·         Known to be live but those involved do not have adequate training or appropriate equipment, or they have not taken adequate precautions.

[Note: - Always assume conductors are ‘Live’ unless proved dead]

Work on or near live conductors is rarely permitted. Many accidents occur when persons are working on equipment that could have been isolated.  Regulations require that ALL of the following three conditions must be met for live working to be permitted;

·         It is unreasonable in all circumstances for the conductor to be dead.

·         It is reasonable in all circumstances for the person to be at work on or near that conductor while it is live.

·         Suitable precautions, including Personal Protective Equipment (PPE), have been taken to prevent injury.

11.7             Equipment

In general, equipment that has been properly designed, constructed, installed and maintained does not present a risk of electric shock or burn injury when used correctly.  Some equipment, not designed to prevent injury from shock or burn, relies on the user having sufficient knowledge and experience to recognise the danger and avoid it.  For example, open-type switchboards, fuse boards, control panels not insulated to IP2X should be located in a secure room or area, with access available only competent persons.

Degrees of Protection

IP2X/IPXXB - Constructed to withstand BS Finger Probe (12mm diameter & 80mm in length).

IEE Regulations, Chapter 41, ‘Protection Against Electric Shock’

Regulation 412-03-04 States: -

‘Where it is necessary to remove a barrier or to open an enclosure, or to remove part of an enclosure, one or more of the following requirements must be satisfied;

i)                    The removal or opening shall only be possible by use of a key or tool.

ii)                  The removal or opening should only be possible after disconnection of the supply to the live part against which the barrier or enclosure affords protection, restoration of the supply being possible only after replacement or re-closure of the barrier of the enclosure.

iii)                 An intermediate barrier shall be provided to prevent contact with a live part, such a barrier affording protection of at least IP2X or IPXXB and removable only by the use of a tool.

Isolation

Means should be provided to securely disconnect electrical equipment from every source of electrical energy, and comply with the following points;

·         Provide a positive break in live conductors.

·         Give clear indication as to whether it is open or closed.

·         Prevent unauthorised operation by Locking Off.

·         Not allow inadvertent reconnection.

User Checks

All users should carry out a general inspection of electrical equipment prior to use.  The purpose of the user inspection is to identify any obvious defects that might affect their safety.  The user should undertake no dismantling of the equipment unless they have been suitably trained.  The equipment should be suitable for it’s intended purpose and be suitable for the environment where it is located or where it is going to be used.  No record would normally be made of a user inspection unless some aspect was unsatisfactory.  If any serious defects are found, the equipment must not be used; it should be removed from the workplace and reported to the responsible person concerned in accordance with company procedures.  The means of isolation should be confirmed and proved.  Examination should confirm that equipment is insulated to at least IP2X, if not then the equipment isolated from the supply and proved dead prior to working.  The user should also consider whether they are aware of any fault in the equipment and whether it works properly.

Additional checks are required for Portable/Hand Held Equipment

·         The flex should be checked to verify that it is in good condition; it should be free from cuts and any fraying or damage.  You should also check that, where the flex is positioned normally, this will not result in damage, for example by being trapped, or be damaged by people walking on it or tripping over it.

·         The plug should be checked to verify that there are no cracks or damage, that there are no signs of overheating, and that the flexible cable is secure in its anchorage.

·         The socket outlet or flex outlet should be examined, where possible, to verify that there are no cracks or damage, and that there are no signs of overheating.

·         Does the appliance work?  Does it switch on and off properly?  Is it free from any signs of contamination, damage to the case, any signs of cracks?  Could there possibly be any access to live parts and can the equipment be used safely.

[Note:  The equipment should be disconnected from the supply while the examination is undertaken]

Finally, you should satisfy yourself that the equipment is being used for the purpose it was originally intended.  If you are unsure, then you should seek guidance from your supervisor, manager or safety advisor

11.8            Assessing The Risk

The first stage in controlling risk is to carry out a risk assessment in order to identify what needs to be done.  The risk of injury from electricity is strongly linked to where and how it is used and the risks are greatest in harsh conditions, for example:

·         In wet surroundings - unsuitable equipment can easily become live and can make its surroundings live;

·         Out of doors - equipment may not only become wet but may be at greater risk of damage.

·         Some items of equipment can also involve greater risk.  Extension leads are particularly liable to damage - to their plugs and sockets, to their electrical connections, and to the cable itself.  Other flexible leads, particularly those connected to equipment, which is moved a great deal, can suffer from similar problems.

11.9            Reducing the risk

·         Only use safe and suitable equipment

·         Choose equipment that is suitable for its working environment.

·         Electrical risks can sometimes be eliminated by using air, hydraulic or hand

·         Powered tools — These are especially useful in harsh conditions.

·         Ensure that equipment is safe when supplied and then maintain it in a safe condition.

·         For portable equipment, use socket-outlets, which are close by, so that equipment can be easily disconnected in an emergency.

·         Isolate supplies prior to working on or examining equipment.

·         Provide a safety device — See RCD’s below.