A Practical Guide to the of the Wiring Regulations

Christopher Kitcher

• Publisher: Routledge
• Year: 2010
• Print ISBN:
  9781138174726
• eBook ISBN:
  9781136431883
• Topic: Technology & Engineering
• Subtopic: Study Guides
• Index: Technology & Engineering

This book covers all the basics of inspection and testing and clearly explains all the legal requirements. It not only tells you what tests are needed but also describes all of them step-by-step with the help of colour photos. Sample forms show how to verify recorded test results and how to certify and fill in the required documentation. The book is also packed with handy advice on how to avoid and solve common problems encountered on the job.

With its focus on the practical side of the actual inspection and testing rather than just the requirements of the regulations, this book is ideal for students, experienced electricians and those working in allied industries, such as plumbers and heating specialists, kitchen and bathroom fitters, alarm installers and others, whether they are working on domestic or industrial installations.

All the theory required for passing the City & Guilds Level 3 Certificate in Inspection, Testing and Certification of Electrical Installations (2391-01) is covered. The book also includes sample questions and scenarios as encountered in the exams. Questions encourage readers to research answers in the On-Site Guide, as required in the exams for Part P Competent Person courses from EAL, NICEIC, NAPIT, BPEC and others. Model answers are provided for all questions. The book will also help prepare students on City & Guilds 2330 Level 3 courses, NVQs and apprenticeship programmes for their practical inspection and testing exams.

Chris Kitcher is an Electrical Installation lecturer at Central Sussex College and has 45 years of experience in the electrical industry.

Chapter 1

Part 1

In this Chapter:

Licensing laws

Manufacturer’s instructions

British standards

Chapter 13

Part 1 describes the range, purpose and essential principles required for compliance with BS 7671. It also identifies the type of installations to which it should be applied, along with any type of installations which are not included.

Regulation 101.1 provides a list of installations which are included in the scope of BS 7671. They are:

• Residential, commercial, industrial and agricultural/horticultural premises

• Caravans, caravan parks and prefabricated buildings

• Construction and demolition sites, fairgrounds, exhibition and shows and any other temporary electrical installations

• Marinas

• External lighting, highway equipment and street furniture

• Mobile and transportable units

• Photovoltaic systems and low-voltage generating sets.

Whilst working on any electrical installation, it should be remembered that other British Standards (BS) must be consulted where they may have an effect on the installation. These installations could include:

• BS 559 and BS EN 50107 for electric signs and high-voltage luminous discharge tube installations

• BS 5266 for emergency lighting

• BS EN 60079 for electrical equipment for explosive gas atmospheres

• BS EN 50281 and BS EN 61241 for electrical equipment for use in the presence of combustible dust

• BS 5839 for fire detection alarm systems in buildings

• BS 6701 for telecommunication systems

• BS 6351 for electric surface heating systems

• BS 6907 for electrical installations for open-cast mines and quarries

• BS 7909 for design and installation of temporary distribution systems delivering a.c. electrical supplies for lighting, technical services and other entertainment-related purposes.

This is not an exhaustive list, and if in doubt when working on an installation, enquiries about the use of other standards should be made.

LICENSING LAWS

Some premises are subject to licensing laws; in other words the local authority may have certain requirements that need to be met before the owners of the installation are granted a licence to operate. These installations include petrol stations, caravan sites, etc. It should be remembered that any additional requirements needed by these statutory bodies are in addition to the requirements set out in BS 7671, not instead of them.

All equipment and materials used in an electrical installation must be of a British Standard (BS) or European norm (BS EN); any equipment or materials which comply with these standards will also comply with BS 7671 provided that they are used for the purpose for which they are intended. It must be remembered that some equipment is only satisfactory when used in a certain way or with suitably matching equipment.

MANUFACTURER’S INSTRUCTIONS

It is a requirement of BS 7671 that all electrical equipment is installed in accordance with the manufacturer’s instructions and documentation. Where this information is not available or has been lost, a call to the manufacturer or supplier will usually provide the required information.

BRITISH STANDARDS

From time to time a designer/electrician may be asked to install equipment which has no standard marked on it; this could possibly be a new invention or new type of material.

Regulations 102.4, 103.1.2 and 103.1.3 cover this situation, and make it very clear that they can be used provided the equipment or materials in question provide the same degree of safety required by BS 7671. This must be agreed between the designer or client and the person responsible for the installation. In many instances, the designer and installer could be the same person. It is not unusual for electricians to be expected to design and install an installation, with the customer often asking that we install equipment supplied by them.

If we are confident that on completion the installation will provide the same degree of safety as expected by BS 7671, it is permissible to use the equipment in the installation. It is also a requirement that we record the fact that we have departed from the requirements of BS 7671 by making a note of the departure on the electrical installation certificate.

It can be seen from the electrical installation certificate in appendix 6 that the designer, installer and the person responsible for carrying out the inspection and test must all agree that the departure is acceptable. If agreement cannot be met then the departure should not be allowed.

CHAPTER 13

Fundamental principles

Where BS 7671 is complied with, a high level of safety protection is provided for any persons, property and livestock which come into contact with the installation.

A good working knowledge of the contents of chapter 13 is vital for any person who is going to design an electrical installation. This chapter sets out the basic principles which are required to be considered within an installation.

Before we can consider designing an installation, a full understanding of these basic principles is very important. Most electricians will know what the fundamental principles are and take most of them into account without a second thought. If these fundamental principles are read carefully, it will be seen that most of them are just common sense requirements.

However, I am pretty sure that most of us would struggle to make a complete list of them. Over the next few pages each fundamental principle is listed and briefly explained. Each principle will also be cross-referenced throughout this book.

131 Protection for safety

The whole reason for BS 7671 being in place is to provide a standard which can be used to ensure the safety of persons, property and livestock when electrical installations are used in the way in which they are designed to be used. BS 7671 also provides a level of safety within installations when things go wrong, during moments of misuse or when accidents occur.

Regulation 131.1 provides us with a general list of possible occurrences which we must consider providing protection against where required. These are:

• Shock currents

• Excessive temperatures

• Explosion

• Under- and overvoltages along with electromagnetic influences

• Mechanical movement of electrically operated equipment

• Arcing or burning

• Power supply interruptions.

Any of the items listed could cause severe injury or damage depending on the circumstances.

Sections 131 to 135 expand on the general list and tell us what we need to consider for each item.

131.2.1 Basic protection

The installation must have in place a method of preventing persons or livestock from touching live parts of the installation which are intended to be live where any contact could result in a current passing through the body, or to limit the current which could pass through a body to a safe level.

Methods of protection are set out in part 4 of the Wiring Regulations. They are:

• Basic insulation of live parts

• Barriers or enclosures

• Obstacles and placing out of reach

• Use of separated extra low voltage (SELV) or protected extra low voltage (PELV).

Basic protection can be achieved by complying with 414, 416 and 417 of BS 7671.

131.2.2 Fault protection

Fault protection is required to protect persons and livestock against electric shock which may arise from contact with exposed or extraneous conductive parts which may become live during a fault.

This can be achieved by any one of the following methods:...

Table of contents

• Cover
• Halftitle
• Title
• Copyright
• Contents
• Foreword
• Preface
• BS 7671 wiring regulations 2008
• Part 1
• Part 2
• Part 3
• Part 4
• Part 5
• Part 6
• Part 7
• Appendices
• Index