Why you shouldn’t spend too much time on the Appendices… At the back of the 18th Edition book ‘BS7671:2018’ we have 17 appendices containing additional or supplementary information to the rules and regulations within the book. If you look though you’ll see that Appendices 11 and 12 are
READ MORECalculating voltage drop… You won’t find this formula anywhere in BS7671:2018 as this is another example of where G&G / EAL assume some prior electrical theory knowledge, but the formula is… Voltage Drop = (mV/A/m) x Ib x L / 1000. (mV/A/m): To find the value for (mV/A/m)
READ MOREThe 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
READ MOREAn End to Protective Equipotential Bonding? There are some significant changes being introduced by the 18th Edition of the Wiring Regulations BS 7671:2018. Chapter 41 has arguably one of the most controversial… “Metallic pipes entering the building having an insulating section at their point of entry need not
READ MOREA new version of the Wiring Regulations will come into effect on the 1st January 2019… The 18th Edition of BS7671:2018 Requirements for Electrical Installations (to give it its full title) introduces some significant changes to the previous 17th Edition of BS7671. This new book if all goes
READ MOREHow an electric shock occurs… An electric shock occurs when a person becomes part of a circuit, with current entering the body at one point and leaving it at another. The two methods of receiving an electric shock are… Coming into contact with a normally live part (i.e.
READ MORE#1: Knowledge of Electricity… A good understanding of the basic principles of electricity is essential, from Ohm’s Law and resistors in series and parallel to power calculations and transformer theory. Including a good working knowledge of cable and protective conductor sizes as well as selecting protective devices their
READ MORESizes of main Bonding Conductors… This can be confusing as the size of the main bonding conductor differs depending on the type of supply. In a TN-S or TT system the main bonding conductor is in relation to the size of the main earthing conductor which is dependant
READ MOREConsumer units in new and modern domestic installations should contain Residual Current Devices ‘RCDs’ as well as circuit breakers. Either as combined RCD/circuit breaker devices ‘RCBOs’ which can get a bit expensive or alternatively and less expensive through the use of split load boards with usually two RCCBs
READ MOREThe most common cable found within a domestic electrical installation is the PVC insulated and sheathed Twin and CPC cable – also known as Twin and Earth. A PVC three core and CPC is also used on two-way lighting circuits, smoke detector interlinks, fans with timers and also
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