Testing Electrical Installations: A Practical Guide for Electricians - Softcover

Anthony Hinsley

Softcover

ISBN 10: 0952532417 ISBN 13: 9780952532415

Publisher: Castleknight Publications, 2005

Synopsis

This is an extremely detailed account of how to carry out practical testing to BS7671, This book is suitable for students studying C&G 2330, 2381, 2391, 2400, NVQ level II, III and domestic installer level 2 courses. Key topics are; Continuity of circuit protective conductors. Continuity of main and supplementary bonding. Insulation resistance. Earth loop impedance. Prospective short circuit current. Prosective earth fault current. Health and safety when testing. Safe isolation. The book contains very clear concise drawings and wiring diagrammes that detail the practicallities of how to test the fixed wiring within installations.

About this title

From the Author

Please remember that all printed material, including my books and GN3 are for guidance and you should use your knowledge, understanding and ability to make an assessment of each individual situation and only carry out a test in a way that you know will avoid danger to persons and damage to property

GN3 states that direct measurement of Zs can only be made on a live installation, neither the connection with earth nor bonding conductors are disconnected. Readings given by the loop impedance tester may be less than Ze + (R1+R2) because of parallel earth return paths provided by any bonded extraneous-conductive-parts.

In my opinion you should disconnect the main equipotential bonding conductors from the incoming gas and water service pipes if they are metallic in order to obtain a realistic value for Zs. (bear in mind that no other bonding conductors should be removed)

If the incoming gas and water service pipes are metallic and the test is carried out with the main equipotential bonding conductors connected, the measurement of Zs becomes worthless and the risk of shock induced into another electrical system in close proximity is un-quantifiable, In my opinion unsafe, uncontrolled and completely out of the hands of the inspector and defiantly in breach of H&S.

About the Author

Anthony Hinsley is a qualified electrician with over 30 years practiocal experience in the industry, who spent 5 years teaching in an FE college and now creating and supplying educational training resources to the electrical industry.

Edition details

• Publisher: Castleknight Publications
• Publication date: 2005
• Language: English
• ISBN 10: 0952532417
• ISBN 13: 9780952532415
• Binding: Paperback
• Number of pages: 80