Product Description

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.

Product Details

• Amazon Sales Rank: #53209 in Books
• Published on: 2006-08-01
• Format: Illustrated
• Original language: English
• Binding: Paperback
• 78 pages

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.

Customer Reviews

Testing Electrical Installations A practical guide for electricians: A Practical Guide for Electricians
I think this is an excellent publication. I take on board the comments about testing for Zs and I agree with the author of the book. I have come across installations where there is no actual true Ze, but it is being provided by other parallel earth paths. Testing this way is about risk assesment and there is a big difference between testing domestic and industrial properties. At least this author has had the courage to pragmatically show testing and the efficient and accurate ways to do it. Too many people think they know how to do it, but have never actually tried to do it. If they had they would understand the confusing results that you get with the effect of the parallel earth path problem - difficult to explain when the sums just do not add up!
My only criticism of the book is that it would have been nice to have had the Zs table and the protective devices table and fault current graphs included out of the regs. It would just reinforce why we are testing and what we are truly looking for.
But an essential for those sparks who need a refresher and don't want long winded explantions and an absolute must for any young sparks starting out, I wish I had this 30 years ago.

An Outstanding guide to testing
This book has good clear diagrams which show you exactly how to carry out testing. This is complemented by clear, easy to understand explanations of what to do and when to do it. In my opinion this is a must have book, always useful when on a job to use as a quick reference guide, I must stress the diagrams are very clear and easy to understand and the explanations down to earth and very understandable.

Very good indeed
Found the book a very good point of reference the full colour pictures help anyone who is not familiar with test procedures. A definate purchase for anyone thinking of doing C&G 2391.