IET Wiring Regulations: Explained and Illustrated

Brian Scaddan

• Publisher: Routledge
• Year: 2018
• Print ISBN: 9781138606067
• eBook ISBN: 9780429882999
• Edition: 11
• Topic: Technology & Engineering
• Subtopic: Civil Engineering
• Index: Technology & Engineering

This popular guide focuses on common misconceptions in the application of the IET Wiring Regulations. It explains in clear language those parts of the regulations that most need simplifying, outlining the correct procedures to follow and those to avoid. Emphasis has been placed on areas where confusion and misinterpretation are common, such as earthing and bonding, circuit design and protection, and in particular the increased use of RCDs.

With the content covering the requirements of both City & Guilds and EAL courses and containing sample exam questions and answers, this book is also an ideal revision guide.

CHAPTER 1

Fundamental Requirements for Safety

Important terms/topics covered in this chapter:

• The Health and Safety at Work Act 1974
• The Electricity at Work Regulations 1989
• The Building Regulations 2010 Part ‘P’
• Distribution Network Operator DNO
• DNO supply voltages and BS 7671 voltage bands
• The Electricity Safety, Quality and Safety Regulations 2002

By the end of this chapter the reader should:

• be aware of the requirements of Part1 and Chapter 13 of BS 7671: 2018,
• understand their responsibilities under the H & S at Work Act and the EAWR,
• be able to demonstrate a knowledge and understanding of the requirements of Part ‘P’,
• know the standard DNO’s supply voltages and tolerances,
• know the BS 7671 voltage bands.

IET WIRING REGULATIONS (IET REGULATIONS PART 1 AND CHAPTER 13)

It does not require a degree in electrical engineering to realize that electricity at low voltage can, if uncontrolled, present a serious threat of injury to persons or livestock, or damage to property by fire.

Clearly the type and arrangement of the equipment used, together with the quality of workmanship provided, will go a long way to minimizing danger. The following is a list of basic requirements:

1. Use good workmanship.
2. Use approved materials and equipment.
3. Ensure that the correct type, size and current-carrying capacity of cables are chosen.
4. Ensure that equipment is suitable for the maximum power demanded of it.
5. Make sure that conductors are insulated, and sheathed or protected if necessary, or are placed in a position to prevent danger.
6. Joints and connections should be properly constructed to be mechanically and electrically sound.
7. Always provide overcurrent protection for every circuit in an installation (the protection for the whole installation is usually provided by the Distribution Network Operator [DNO]), and ensure that protective devices are suitably chosen for their location and the duty they have to perform.
8. Where there is a chance of metalwork becoming live owing to a fault, it should be earthed, and the circuit concerned should be protected by an overcurrent device or a residual current device (RCD).
9. Ensure that all necessary bonding of services is carried out.
10. Do not place a fuse, a switch or a circuit breaker, unless it is a linked switch or circuit breaker, in an earthed neutral conductor. The linked type must be arranged to break all the line conductors.
11. All single-pole switches must be wired in the line conductor only.
12. A readily accessible and effective means of isolation must be provided, so that all voltage may be cut off from an installation or any of its circuits.
13. All motors must have a readily accessible means of disconnection.
14. Ensure that any item of equipment which may normally need operating or attending by persons is accessible and easily operated.
15. Any equipment required to be installed in a situation exposed to weather or corrosion, or in explosive or volatile environments, should be of the correct type for such adverse conditions.
16. Before adding to or altering an installation, ensure that such work will not impair any part of the existing installation and that the existing is in a safe condition to accommodate the addition.
17. After completion of an installation or an alteration to an installation, the work must be inspected and tested to ensure, as far asreasonably practicable, that the fundamental requirements for safety have been met.

These requirements form the basis of the IET Regulations.

It is interesting to note that, whilst the Wiring Regulations are not statutory, they may be used to claim compliance with Statutory Regulations such as the Electricity at Work Regulations, the Health and Safety at Work Act and Part ‘P’ of the Building Regulations. In fact, the Health and Safety Executive produces guidance notes for installations in such places as schools and construction sites. The contents of these documents reinforce and extend the requirements of the IET Regulations. Extracts from the Health and Safety at Work Act, the Electricity at Work Regulations and Part ‘P’ of the Building Regulations are reproduced below.

THE HEALTH AND SAFETY AT WORK ACT 1974

Duties of employers

Employers must safeguard, as far as is reasonably practicable, the health, safety and welfare of all the people who work for them. This applies in particular to the provision and maintenance of safe plant and systems of work, and covers all machinery, equipment and appliances used.

Some examples of the matters which many employers need to consider are:

1. Is all plant up to the necessary standards with respect to safety and risk to health?
2. When new plant is installed, is latest good practice taken into account?
3. Are systems of work safe? Thorough checks of all operations, especially those operations carried out infrequently, will ensure that danger of injury or to health is minimized. This may require special safety systems, such as ‘permits to work’.
4. Is the work environment regularly monitored to ensure that, where known toxic contaminants are present, protection conforms to current hygiene standards?
5. Is monitoring also carried out to check the adequacy of control measures?
6. Is safety equipment regularly inspected? All equipment and appliances for safety and health, such as personal protective equipment, dust and fume extraction, guards, safe access arrangement, monitoring and testing devices, need regular inspection (Section 2(1) and 2(2) of the Act).

No charge may be levied on any employee for anything done or provided to meet any specific requirement for health and safety at work (Section 9).

Risks to health from the use, storage, or transport of ‘articles’ and ‘substances’ must be minimized. The term substance is defined as ‘any natural or artificial substance whether in solid or liquid form or in the form of gas or vapour’ (Section 53(1)).

To meet these aims, all reasonably practicable precautions must be taken in the handling of any substance likely to cause a risk to health. Expert advice can be sought on the correct labelling of substances, and the suitability of containers and handling devices. All storage and transport arrangements should be kept under review.

Safety information and training

It is now the duty of employers to provide any necessary information and training in safe practices, including information on legal requirements.

Duties to others

Employers must also have regard for the health and safety of the self-employed or contractors’ employees who may be working close to their own employees, and for the health and safety of the public who may be affected by their firm’s activities.

Similar responsibilities apply to self-employed persons, manufacturers and suppliers.

Duties of employees

Employees have a duty under the Act to take reasonable care to avoid injury to themselves or to others by their work activities, and to cooperate with employers and others in meeting statutory requirements. The Act also requires employees not to interfere with or misuse anything provided to protect their health, safety or welfare in compliance with the Act.

THE ELECTRICITY AT WORK REGULATIONS 1989

Persons on whom duties are imposed by these Regulations

1. Except where otherwise expressly provided in these Regulations, it shall be the duty of every:
   1. employer and self-employed person to comply with the provisions of these Regulations in so far as they relate to matters which are within his or her control; and
   2. manager of a mine or quarry (within in either case the meaning of Section 180 of the Mines and Quarries Act 1954) to ensure that all requirements or prohibitions imposed by or under these Regulations are complied with in so far as they relate to the mine or quarry or part of a quarry of which he or she is the manager and to matters which are within his or her control.
2. It shall be the duty of every employee while at work:
   1. to cooperate with his or her employer in so far as is necessary to enable any duty placed on that employer by the provisions of these Regulations to be complied with; and
   2. to comply with the provisions of these Regulations in so far as they relate to matters which are within his or her control.

Employer

1. For the purposes of the Regulations, an employer is any person or body who (a) employs one or more individuals under a contract of employment or apprenticeship; or (b) provides training under the schemes to which the HSW Act applies through the Health and Safety (Training for Employment) Regulations 1988 (Statutory Instrument No. 1988/1222).

Self-employed

2. A self-employed person is an individual who w...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Preface
• Introduction
• Chapter 1 Fundamental Requirements for Safety
• Chapter 2 Earthing
• Chapter 3 Protection
• Chapter 4 Isolation Switching and Control
• Chapter 5 Circuit Design
• Chapter 6 Inspection and Testing
• Chapter 7 Special Locations IET Regulations Part 7
• Appendix A 18th Edition: Examination Question Sample Paper
• Appendix B Answers to Multiple Choice Test
• Index