The 18th Edition exam is an assessment of your ability to use the Wiring Regulations BS7671 2018 out there in the big world. As such problems and questions may not always be worded exactly as you come across them in the book.
The first step to answering a real life problem or any exam question for that matter is to ask yourself. ‘What part of the book does this relate to?’
The book has been written in a logical order that flows from front to back and not just placed together at random.
The first two Parts are all about the book…
Part 1: Scope, object and fundamental principles…
Is all about the book. What BS7671 does and does not apply to (Chapter 11 ‘Scope’) along with the purpose of the regulations (Chapter 12 ‘Object’) and the basic principles that all electrical installations should adhere to (Chapter 13 ‘Fundamental Principles’).
Part 2: Definitions…
This part explains the common terms and abbreviations used throughout the book.
Then, when you are designing and installing an electrical installation you’ll need to follow the rest of the book… (applying the fundamental principles of Chapter 13)
Part 3: Assessment of general characteristics…
This part deals with all of the things that should be considered before installing and when designing an electrical installation. It’s purpose, how it’s going to be supplied, any environmental conditions to consider and the need for maintenance etc.
Part 4: Protection for safety…
This is the main Part of BS7671 and has the requirements that should be followed in order to provide a safe electrical installation that reduces the risk of injury or damage to the installation under the following conditions…
Electric shocks ‘Chapter 41’. Excessive heat or fire ‘Chapter 42’. Overloads ‘Chapter 43’ and any possible voltage disturbances such as surges, or loss of voltage ‘Chapter 44’.
Part 5: Selection and erection of equipment…
Deals with the ‘cables, earthing, accessories and equipment etc’ that form the physical parts of an electrical installation and what materials you must use in order to comply with the requirements for safety that were mentioned in Part 4.
Part 6: Inspection and testing…
Lays out what you should do (inspect and test) in order to demonstrate that a new or existing electrical installation complies with the Wiring Regulations and is safe and fit for purpose. Plus, the certificates/reports that must be completed as a record of the condition of the installation.
Part 7: Special installations or locations…
Additional regulations that apply to environments or situations where due to their nature, wet (bathrooms, marinas etc) or unusual conditions with unskilled, unsupervised users (medical location, electric vehicle charging etc) there is a higher risk of electric shock than would normally exist.
Appendices…
Additional, supplementary information relating to other parts of the book – eg Appendix 6 has copies of the certificates and reports used with Inspection and Testing – Part 6 and Appendix 3 has the maximum disconnection times for RCDs and current/time graphs for protective devices which ties into Part 4 etc.
In summary…
Part 1: What it does and doesn’t apply to and what it aims to achieve
Part 2: What terms and abbreviations mean
Part 3: Things to consider during the initial design of an installation
Part 4: What to do to protect the user and installation
Part 5: What materials to use
Part 6: What inspections and tests should be done to show it’s safe and the certificates to be used.
Part 7: Places where there is an increased risk of electric shock and what to do
Appendices: Additional information relating to parts within the book.
Once you have decided what Part of the 18th Edition BS7671 your problem relates to go to the table of contents for that particular Part and find which Chapter it relates to.
There are also tables of contents for each particular Chapter which can also help to narrow down your search.