Health and Safety

The Electricity at Work Regulations 1989 Subtitle H6

Guidance on Regulations

Health and Safety Executive This new edition of HSR25 will help dutyholders meet the requirements of the The Electricity at Work Electricity at Work Regulations 1989. It will be of interest and practical help to all Regulations 1989 Subtitle H6 dutyholders, particularly engineers (including those involved in the design, construction, operation or maintenance of electrical systems), technicians and their managers.

It sets out the Regulations and gives technical and legal guidance on them. The purpose of this guidance is to highlight the nature of the precautions in general terms to help dutyholders achieve high standards of electrical safety in compliance with the duties imposed.

This third edition removes reference to regulations 17–28 and Schedule 1, which Guidance on Regulations applied only to mines and were revoked in April 2015 by the Mines Regulations HSR25 (Third edition) 2014, and shows changes made to regulations 3 and 29. This document applies to Published 2015 all electrical systems and there is additional guidance for mines in Electrical safety in mines (HSE publication HSG278).

The publication also contains references to HSE guidance and codes of practice from other standards-making bodies and trade associations.

HSE Books

© Crown copyright 2015

First published 1989 Second edition 2007 Third edition 2015

ISBN 978 0 7176 6636 2

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Guidance

This guidance is issued by the Health and Safety Executive. Following the guidance is not compulsory, unless specifically stated, and you are free to take other action. But if you do follow the guidance you will normally be doing enough to comply with the law. Health and safety inspectors seek to secure compliance with the law and may refer to this guidance.

Contents

Introduction 5 The Regulations 7 Regulation 1 Citation and commencement 7 Regulation 2 Interpretation 7 Regulation 3 Persons on whom duties are imposed by these Regulations 13 Regulation 4 Systems, work activities and protective equipment 15 Regulation 5 Strength and capability of electrical equipment 18 Regulation 6 Adverse or hazardous environments 19 Regulation 7 Insulation, protection and placing of conductors 22 Regulation 8 Earthing or other suitable precautions 25 Regulation 9 Integrity of referenced conductors 29 Regulation 10 Connections 30 Regulation 11 Means for protecting from excess of current 31 Regulation 12 Means for cutting off the supply and for isolation 33 Regulation 13 Precautions for work on equipment made dead 35 Regulation 14 Work on or near live conductors 37 Regulation 15 Working space, access and lighting 41 Regulation 16 Persons to be competent to prevent danger and injury 42 Regulations 17–28 43 Regulation 29 Defence 43 Regulation 30 Exemption certificates 44 Regulation 31 Extension outside Great Britain 44 Regulation 32 Disapplication of duties 45 Regulation 33 Revocations and modifications 45 Appendix 1 46 References and further reading 48 Further information 52

Introduction

About this book

1 This book gives guidance on and sets out the Electricity at Work Regulations 1989. The guidance is relevant to all work activities and premises except certain offshore workplaces and certain ships. Additional guidance specific to mines is given in Electrical safety in mines.1

2 The Electricity at Work Regulations 1989 (SI 1989/635) (as amended) (the Regulations) came into force on 1 April 1990. The purpose of the Regulations is to require precautions to be taken against the risk of death or personal injury from electricity in work activities. The text of the Regulations is available free to download from legislation.gov.uk or to purchase from The Stationery Office.

3 The Regulations are made under the Health and Safety at Work etc Act 1974 (the HSW Act).2 The HSW Act applies principally to employers, the self-employed and to employees, including certain classes of trainees. Duties are imposed on people (referred to in this guidance as ‘dutyholders’) in respect of systems, electrical equipment and conductors, and in respect of work activities on or near electrical equipment. Words in bold (above and in extracts from the Regulations) are defined in regulation 2. The duties are in addition to those imposed by the HSW Act. The 1989 Regulations pre-date the risk assessment process brought in with the 1992 version of the Management of Health and Safety at Work Regulations. However, the risk assessment process is still required. Further information can be found in Managing for health and safety.3

What are the differences between this edition and the previous edition? 4 This third edition notes that regulations 17–28 and Schedule 1, which applied only to mines, were revoked in April 2015 by the Mines Regulations 2014. These Regulations also modified regulations 3 and 29.

Who should read this book?

5 The guidance is primarily for dutyholders (including those involved in the design, construction, operation or maintenance of electrical systems and equipment), engineers, technicians and their managers. It sets out the Regulations and gives technical and legal guidance on them. While it reflects the Health and Safety Executive’s (HSE’s) view of the meaning of terms used in the Regulations, only the Courts can provide a binding interpretation. The text of the Regulations is set out in italics, the accompanying guidance is in normal type. Coloured borders also indicate each section clearly.

Scope

6 This guidance applies to all operational voltages.

7 The Regulations apply to all electrical systems and equipment (as defined) whenever manufactured, purchased, installed or taken into use even if its manufacture or installation pre-dates the Regulations. Where electrical equipment pre-dates the Regulations this does not of itself mean that the continued use of the equipment would be in contravention of the Regulations. For example, some of the equipment to which the Regulations apply may have been made to a standard, such as a British Standard, which has since been modified or superseded. Standards such as BS 76714 can provide assistance but, ultimately, compliance with the Regulations is required. It is likely to be reasonably practicable to replace it with equipment made to a more recent standard when, but only when, it becomes unsafe or falls due for replacement for other than safety reasons, whichever occurs sooner.

British Standard BS 7671 Requirements for Electrical Installations (also known as the IET Wiring Regulations) 8 BS 7671 Requirements for electrical installations is also known as the IET Wiring Regulations. They are non-statutory regulations which ‘relate principally to the design, selection, erection, inspection and testing of electrical installations, whether permanent or temporary, in and about buildings generally and to agricultural and horticultural premises, construction sites and caravans and their sites’.

9 BS 7671 is a code of practice which is widely recognised and accepted in the UK and compliance with it is likely to achieve compliance with relevant aspects of the Electricity at Work Regulations 1989.

10 There are, however, many types of system, equipment and hazard to which BS 7671 is not applicable; for example, certain installations at mines and quarries, equipment on vehicles, systems for public electricity supply and explosion protection. Furthermore, BS 7671 applies only to installations operating at up to 1000 V ac or 1500 V dc.

11 Installations to which BS 7671 is relevant may have been installed in accordance with an earlier edition, now superseded but then current. That, in itself, would not mean that the installation would fail to comply with the Regulations.

Electricity Safety, Quality and Continuity Regulations

12 The Electricity Safety, Quality and Continuity Regulations 2002 (ESQCR)5 impose requirements in respect of the generation, distribution and supply of electricity, including supply networks and electrical equipment. The Department of Energy and Climate Change (DECC) leads on ESQCR matters, though HSE performs some functions on DECC’s behalf, in particular with regards to public safety and incident notifications. Some ESQCR obligations – such as requirements for connection with earth – overlap with the Regulations, but others provide additional requirements.

The Regulations

Regulation 1 Citation and commencement Regulation 1 These Regulations may be cited as the Electricity at Work Regulations 1989 and shall come into force on 1st April 1990.

Regulation 2 Interpretation Regulation 2 (1) In these Regulations, unless the context otherwise requires –

“circuit conductor” means any conductor in a system which is intended to carry electric current in normal conditions, or to be energised in normal conditions, and includes a combined neutral and earth conductor, but does not include a conductor provided solely to perform a protective function by connection to earth or other reference point;

“conductor” means a conductor of electrical energy;

“danger” means risk of injury;

“electrical equipment” includes anything used, intended to be used or installed for use, to generate, provide, transmit, transform, rectify, convert, conduct, distribute, control, store, measure or use electrical energy;

“injury” means death or personal injury from electric shock, electric burn, electrical explosion or arcing, or from fire or explosion initiated by electrical energy, where any such death or injury is associated with the generation, provision, transmission, transformation, rectification, conversion, conduction, distribution, control, storage, measurement or use of electrical energy;

“system” means an electrical system in which all the electrical equipment is, or may be, electrically connected to a common source of electrical energy, and includes such source and such equipment.

Guidance 2 13 Words and phrases which are in bold type in the text of the regulation preceding the guidance are those which have been assigned a special meaning by being defined in regulation 2.

Systems

14 The term ‘system’ includes all parts of a system, eg conductors and electrical equipment in it, and is not a reference solely to the functional circuit as a whole. It follows that something required of a system is required both of the system as a whole and of the equipment and conductors in it.

Guidance 2 15 The definition refers to electrical systems. In the case of each system this will include all of the electrical equipment connected together and the various electrical energy sources in that system. In the case of transformers, even though there may be galvanic separation between the various windings of the transformers, where the energy is transmitted through these from one part of the electrical system to another, the transformer and all of its windings are part of the same system.

16 The definition of ‘system’ includes equipment which, although not energised, may be electrically connected to a common source of electrical energy. Equipment which is readily capable of being made live by a system is therefore considered to be part of that system. For example, a lighting circuit which has been disconnected from its source of electrical energy by means of removable links or fuses is still part of that system, as is such a circuit which has been switched off even though the switch might be a double pole switch.

17 Equipment which is in any way connected to a source of electrical energy, eg a test instrument containing a source and the equipment containing or connected to that source, becomes part of a system and the Regulations apply to that system. Electrical equipment which is not connected, and cannot be readily connected, to a source of electrical energy is not part of a system. Protective conductors, if they are connected to a source, are part of that system.

18 The reference in the definition to a common source of electrical energy does not exclude systems fed by several generators or transformers. The word ‘common’ is included in the definition so that completely independent electrical installations are regarded as separate systems. If, however, they are electrically connected in any way they are part of the same system for the purposes of the Regulations. This may mean that the system may be an extensive electrical network covering large geographical areas over which several or even many people have control of various parts. The Regulations place duties on these people only in respect of those provisions of the Regulations which relate to matters which are within their control (see regulation 3).

19 Self-contained portable systems, such as portable generating sets, are electrical systems for the purpose of the Regulations, as are transportable systems and systems on vehicles etc.

Electrical equipment 20 ‘Electrical equipment’ as defined in the Regulations includes every type of electrical equipment from, for example, a high-voltage transmission overhead line to a battery-powered hand lamp. There are no voltage limits in the Regulations; the criteria are whether danger (as defined) may arise. It is appropriate for the Regulations to apply even at the very lowest end of the voltage or power spectrum because the Regulations are concerned with, for example, explosion risks, which may be caused by very low levels of energy igniting flammable gases even though there may be no risk of electric shock or burn.

21 Electrical equipment (as defined) includes conductors used to distribute electrical energy such as cables, wires and leads and those used in the transmission at high voltage of bulk electrical energy, as in the national grid.

Conductors

22 Regulation 2 defines a conductor as ‘a conductor of electrical energy’. This means any material which is capable of conducting electricity (electricity is synonymous with electrical energy) and therefore includes both metals and all other

Guidance 2 conducting materials. The definition is not limited to conductors intended to carry current and so includes, for example, metal structures, salt water, ionised gases and conducting particles. The conductance of most materials varies with parameters such as temperature, eg glass is conducting when molten (and is then a conductor, as defined) whereas in its normal, solid, state it is a good insulator and finds many applications as such. For the purposes of the Regulations, while such materials conduct electricity, they are ‘conductors’.

Figure 1 Types of conductor

L1 These conductors enclosed by this dotted line are circuit conductors (by definition) L2

L3

N

E

Within these dotted linesthe conductors are conductors in a system since they are electrically connected to a common source of electrical energy

3 Phase system – separate neutral and earth

These are conductors in a system But not circuit conductors L

N

Protective conductor The combined neutral/earth conductor serves as both a neutral and a protective conductorand is therefore a circuit conductor as well as a conductor in a system

System including both combined and separate neutral and earth conductors (single phase only shown)

Guidance 2 Circuit conductor

23 This definition is used in regulations 8 and 9 only. It distinguishes from all other conductors those conductors whose normal function is to carry load current or to be energised (see Figure 1).

Danger

24 The Regulations use the two defined terms, ‘danger’ and ‘injury’. ‘Danger’ is defined as ‘risk of injury’. ‘Injury’ is defined in terms of certain classes of potential harm to people.

25 Where the term ‘prevent danger’ is used it should therefore be read as ‘prevent the risk of injury’.

26 The Regulations make requirements to ‘prevent danger’ or ‘prevent injury’ – or in the case of regulation 16 – ‘to prevent danger or, where appropriate, injury’. The purpose of the distinction between ‘injury’ and ‘danger’ is to accommodate those circumstances when people must work on or so near live equipment that there is a risk of ‘injury’, ie where ‘danger’ is present and cannot be prevented. In these circumstances, under regulation 14, danger may be present but injury must be prevented.

27 The type of injuries with which the Regulations are concerned are detailed in the definition of ‘injury’ in the regulation (see paragraphs 29 and 30). The scope of the Regulations does not include consequential dangers such as crushing injuries caused by a machine going out of control following an electrical malfunction. Such other dangers are subject to other legal requirements under, for example, the HSW Act, the Factories Act 1961 and the Office, Shops and Railway Premises Act 1963.

28 If no danger arises from a particular system, item of electrical equipment or conductor and will not arise, then the Regulations, although applying to it, do not require any precautions to be taken. However, in order for there to be no danger, there would have to be no risk of electric shock, electric burn, fire, arcing or explosion.

Injury

29 The purpose of the Regulations is to prevent death or personal injury to any person from electrical causes in connection with work activities.

30 ‘Injury’ means death or injury to any person from:

(a) electric shock; (b) electric burn; (c) fires of electrical origin; (d) electric arcing; (e) explosions initiated or caused by electricity.

Electric shock 31 The human body responds in several ways to electrical current flowing through it. The sensation of shock is only one such effect and this can be extremely painful. When a shock is received, the electric current may take multiple paths through the body and its intensity at any one point is difficult or impossible to predict. The passage of electric current may cause muscular contractions, respiratory failure, fibrillation of the heart, cardiac arrest or injury from internal burns. Any of these can be fatal.

Guidance 2 32 The nature and severity of injury depends upon the magnitude, duration and path of the current through the body and, in the case of alternating current (ac), on its frequency. It is not possible to identify precise thresholds for the existence of hazard because a judgement has to be made in each case taking all the circumstances into account, such as body weight, physical condition of the victim and so forth. Nevertheless, a guide to the sort of current magnitudes which mark the occurrence of various dangerous effects is given in the International Electrotechnical Commission’s (IEC’s) publication Guide to effects of current on human