BS 7671: 18th Edition Wiring Regulations – Study when you want and pass your exam when you're ready…
Just a quick post about a question that is often asked… “Do I need to earth the metal back box for a socket?” A metal back box for a socket would be classed as an exposed-conductive part and as such it needs to be earthed. If the back box has a fixed lug on one … Read more
The maximum disconnection times for a TT system is 0.2 seconds for final circuits up to and including 32A (Table 41.1) and for distribution circuits or circuits greater than 32A it’s 1 second (411.3.2.4). The problem is that with TT systems the external loop impedance value (Ze) will be too high to achieve these 0.2 … Read more
Prospective Fault Current (Ipf) is the general term used for the highest amount of current that will flow under fault conditions. On a single phase installation fault conditions can either be Prospective Earth Fault Current (PEFC) Line to Earth or Prospective Short Circuit Current (PSSC) Line to Neutral. Whichever one is the highest would be … Read more
How it works Our 17th Edition online training course is real home training and support and based on a traditional 3 – 4 day classroom course. Specially designed to prepare and assist you in passing your City & Guilds 2382-10 exam. Let’s go through the book together A full cover to cover review (Part 1 to … Read more
If you carry out electrical installations dwellings in England, Scotland or Wales not only are you expected to be able to comply with the HASAWA ‘risk assessments, safe working practices etc’ the EAWR ‘demonstrated by compliance with BS7671’ but also any relevant parts of the Building Regulations for example… Part A: Structural – Depth of cases, positions and sizes of holes and notches. … Read more
BS7671 Part 3 Chapter 31 Purpose, Supplies and Structure 311 Maximum Demand and Diversity Regulation 311.1 …….. In determining the maximum demand of an installation diversity may be taken into account. What this means is that not everything will be switched on at the same time and we can make allowances for that. Domestic installations: Applying … Read more
Companies have a legal duty to ensure that suitable arrangements are in place to manage health and safety. Documented risk assessments must be made if the company employs 5 or more people and these records must be kept. Basically: Assess the possible risks. Determine the possible consequences. Who or what will be affected. Evaluate the … Read more
In a TN earthing system the cornerstone of protection against electric shock is that the protective device ‘circuit breaker’ shall not exceed it’s maximum disconnection time. For a 230 v to earth TN system (covers both single phase and 3-phase) that is 0.4 seconds (final circuits less than or equal to 32A) see T41.1 and 5 seconds (distribution circuits and >32A) see … Read more
The following safe isolation procedure could save your life. If you have no experience and/or knowledge then you can’t avoid the dangers that are present and you should not be working on any electrical circuits or equipment. If in doubt always consult a competent (electrically skilled) person. Select an approved tester (see GS38). Inspect to … Read more
Here are 6 random questions likely to show up in your City & Guilds 2382-15 exam. I’ll won’t give you the answers but I’ll tell you where to look… BS7671 does not include requirements for Have a look at Part 1 Chapter 11 Scope this is where you’ll find what the 17th Edition applies to … Read more