Electricity at Work
Electrical safety is an important issue for ensuring the safety of employees and the working environment whether it is through the use of electrical equipment or the safety of the main distribution system.
Electricity holds a number of possible hazards all of which have the potential to be fatal for example:
- Flashover injuries
- Electric Shock
- Electric Burns
The risk of injury from electricity is linked to where and how it is used. The risks are greatest in harsh conditions, for example:
- In wet surroundings
- Out of doors
- In cramped spaces with a lot of earthed metal work
The requirement for the maintenance and use of electricity in the workplace is covered by the Electricity at Work Regulations.
These regulations incorporate the fundamental principles of electrical safety applying to a wide range of plant, systems and work activities. They apply to all places of work and electrical systems at all voltages.
Some items of equipment involve greater risk than others, for example, extension leads. The first stage in controlling the risks is to carry out a risk assessment. Once the risk assessment is completed you can use the findings to reduce unacceptable risks from the electrical equipment in your place of work.
There are many ways this can be achieved for example:
Ensure that the Electrical Installation is Safe
An electrical system is a system in which all electrical equipment is, or may be, electrically connected to a common source of electrical energy and includes the source and the equipment.
Ultimately electrical systems must be constructed and maintained at all times to prevent danger, so far as is reasonably practicable. Any installation or maintenance must be carried out by a competent person.
Regular visual checks of all electrical equipment should be carried out to establish if there are any obvious faults. Equipment should be visually checked at each use and a formal inspection carried out at set intervals.
In order to achieve this it may be suitable to produce a checklist for electrical items (Appendix 12). Employees should be instructed of the action to be taken should they find a fault with any equipment. There should be enough socket outlets as overloading by using adapters can cause fires.
Provide Safe and Suitable Equipment
Electrical equipment must not be put into use where its strength and capability may be exceeded so as to give rise to danger.
Equipment should be suitable for the working environment. This means potential fault conditions, certain electrochemical, electromagnetic and thermal conditions must be taken into account and that the equipment must be used within the manufacturer’s rating. A suitable CE marking indicates that at the time of construction the equipment complied with The Supply of Machinery (Safety) Regulations and the current EC health and safety legislation.
It is essential when choosing equipment for use in a work environment that it is suitable for use and will consequently be safe. When considering the environment, it is necessary to look at both natural and man-made hazards that may require special protective measures to be taken. For example equipment may be subjected to:
- Mechanical damage e.g. impact, stress, strain, abrasion, wear, vibrations, etc.
- Weather e.g. wind, rain, ice, snow, lighting, temperature fluctuations
- Natural damage e.g. animals, trees, tides, radiation, etc.
- Dirt and dusts
- Combustible and explosive dusts
- Corrosive effects
It may be necessary to discuss the equipment’s use with the manufacturer to ensure that it is safe for the purpose you intend to use it for or it may be necessary to provide further protective measures as detailed later.
There are a number of criteria that may be available on certain pieces of equipment to offer further protection. For example:
- Use of double insulated equipment
- Use of trunking and conduits to protect cables and wiring
- Use of suitably rated plugs and sockets to protect against dust and water
- Use of low temperature equipment in combustible atmospheres
- Insulation, Protection and Placing of Conductors
Precautions must be taken, by earthing or by other suitable means, to prevent danger from a conductor which may become charged either as a result of the use of the system or of a fault of the system. Earthing may be used as a protective measure in the form of:
- Circuit Breakers
- Residual Current Device (RCD)
Residual Current Devices may offer a second line of defence to a system where a high voltage is used. RCDs can detect a number of faults in electrical systems, in which event the electrical supply is automatically switched off. The device may be fitted at the socket or combined into the distribution system.
Where to use RCDs:
- Where an electrical high-pressure washer is being used
- Where a disco/band are using the electrical supply in a hotel
- Voltage Reduction
Limiting the supply voltage to the lowest needed to get the job done is one of the best ways of reducing the risk of injury when using electrical equipment. For example:
- Temporary lighting can be run at 12, 25, 50 or 110 volts
- Use of battery operated power tools
- Portable tools are readily available which are designed to be run from a 110 volts centre-tapped-to-earth-supply
Connections used in the joining of electrical systems must be both mechanically and electrically suitable.
This means that all connections in circuits and protective conductors including connections to terminals, plugs, sockets and any other means of joining or connecting conductors should be suitable for the purposes for which they are used. Any connection made between cables, whether they are temporary or permanent must ensure the following:
- Connections must be suitably insulated and offer suitable conductance
- All connections must be of sufficient strength taking their position into account
- Connections should be checked as part of the maintenance programme detailed previously
- No live conductors should be exposed
This list is by no means exhaustive and the overriding requirement is that the systems must be maintained and constructed in such a manner as to prevent danger.
Means for Cutting Off the Supply and for Isolation
There must be suitable means provided for cutting off energy supply to and the isolation of electrical equipment. Switching off can be achieved by stop buttons, isolation includes ensuring that the supply remains switched off and that inadvertent reconnection is prevented.
Persons to be Competent to Prevent Danger and Injury
Restrictions are placed on who can work where technical knowledge or experience is necessary to prevent danger or injury. They must possess the necessary knowledge or experience or be under appropriate supervision having regard to the nature of the work.
Q. So who is a competent person?
For most part when inspecting portable electrical equipment any sensible, experienced member of staff can do it that has been given enough knowledge and training.
They need to know:
- what to look at
- what to look for
- what to do
- but more importantly they should be able to avoid dangers to themselves and others.
So they should have the necessary knowledge together with common sense e.g. switch off and unplug the equipment first. By concentrating on a simple inexpensive system of looking for visible signs of damage or faults most of the electrical risks can be controlled. This will need to be backed up by testing as and when necessary.
Recommended inspection frequencies for electrical items in low risk premises
(adapted from HSE Guidance IND(G) 164 L)
|Equipment / environment||User checks||Formal visual inspection||Combined inspection and testing*|
|Battery operated (<20 volts)||No||No||No|
|Extra voltage (<50 volts AC) e.g. telephones, low voltage desk lights||No||No||No|
|Information technology e.g. PCs, etc||No||Yes, 2-4 years||No if double insulated, otherwise up to 5 years|
|Photocopies, fax machines which are not handheld and rarely moved||No||Yes, 2-4 years||No if double insulated, otherwise up to 5 years|
|Double insulated equipment which is not hand held and moved occasionally||No||Yes, 2-4 years||No|
|Double insulated equipment which is hand held||Yes||Yes, 6 months - 1 year||No|
|Earthed equipment e.g. kettles, floor cleaners, etc||Yes||Yes, 6 months - 1 year||Yes, 1-2 years|
|Cables and extension leads||Yes||Yes, 6 months - 4 years depending on the type of equipment it is connected to||Yes, 1-5 years depending in the type of equipment it is connected to|
The maintenance system should be based on experience of dealing with equipment taking into consideration any faults found.
Portable Electrical Equipment - Combined Inspection and Testing
- The combined inspection and testing does not necessarily have to be carried out by an electrician.
- It may be a member of staff who has had suitable training.
- Greater knowledge and experience is required than for inspection alone, and they need to have the right equipment to do the appropriate tests. They also need to know how to use the testing equipment correctly and how to interpret the results.
- If there is no suitably qualified or competent persons then it is recommended that you employ an electrician.
It is recommended that fixed installations including wiring are inspected and tested periodically by a competent electrician. The term competent in this case means having the necessary technical knowledge and experience to prevent danger and injury.
The scope of this technical knowledge and experience may include:
- Adequate knowledge of electricity
- Adequate experience of electrical work
- Adequate understanding of the system to be worked on and practical experience of the class of system
- Understanding of the hazards that may arise during the work and the precautions that need to be taken
- The ability to recognise at all times whether it is safe for work to continue
The Periodic Inspection Report as detailed in BS 7671 (IEE Wiring Regulations) is intended for reporting on the condition of an existing electrical installation.
The Contractor should provide a report which should be retained and be shown to any person inspecting or undertaking work on the electrical installation in the future. If the property is later vacated this Report will provide details to the new owner of the condition of the electrical installation at the time the Report was issued.
- Inspection Schedule (pdf 82 kb)
- Periodic Inspection Report (pdf 183 kb)
- Periodic Inspection Report - Guidance (pdf 183 kb)
- Testing Schedule (pdf 130 kb)
Recommended Periodic Inspection periods for fixed installations
(adapted from BS 7671 - IEE Wiring Regulations)
|Type of Installation||Maximum period |
|Domestic||Change of Occupancy/10 years||---|
|Commercial||Change of Occupancy/ 5years||2|
|Education establishments||5 years||1, 2|
|Hospitals||5 years||1, 2|
|Industrial||3 years||1, 2|
|Residential Accommodation||5 years||1|
|Buildings Open to the Public|
|Cinemas||1 to 3 year||2, 6, 7|
|Leisure complexes||3 years||1, 2, 6|
|Places of public entertainment||3 years||1, 2, 6|
|Restaurants and hotels||5 years||1, 2, 6|
|Theatres||3 years||2, 6, 7|
|Public Houses||5 years||1, 2, 6|
|Village Hall/Community Centre||5 years||1, 2|
|Agricultural and horticultural||3 years||1, 2|
|Caravan sites||1 year||1, 2, 7|
|Highway power supplies||6 years||---|
|Fish Farms||1 year||1, 2|
|Swimming Pools||1 year||1, 2, 6|
|Emergency lighting||3 years||2, 3, 4|
|Fire alarms||1 year||2, 4, 5|
|Laundrettes||1 year||1, 2, 6|
|Petrol filling stations||1 year||1, 2, 6|
|Construction site installations||3 months||1, 2|