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18th Edition Wiring Regulations, What's The Problem

Ok so you've had a chance to have your say, but lets have a look at what others are saying about the 18th edition wiring regulations. Blue text is a direct copy of comments made by others and black is just my opinion on what they are saying. This is not an exhaustive list and I will add more in other sessions.

Ring Final circuits are still included in the 18th edition wiring regulations, some feel this type of circuit should have been done away with in the 17th edition. The circuit was introduced many years ago at a time of copper shortage and deliberately uses undersized condutors to feed a circuit of unknown load with an unlimited amount of socket outlets. This is compuonded by the fact that Ring Final circuits are more troublesome to fault find. I am in agreement with the person who made the comment on the DPC to do away with this type of circuit and even introduce a limit to the amount of socket outlets that may be used on a radial circuit.


An important clause from BS7671 has been deleted and not included in the DPC Introduction.


"The Regulations apply to the design, erection and verification of electrical installations, also additions and alterations to existing installations. Existing installations that have been installed in accordance with earlier editions of the Regulations may not comply with this edition in every respect. This does not necessarily mean

Without the inclusin of the above it may become unclear as to what is and what is not an absolute requirement. This may have big implications for periodic inspection and testing under the 18th edition


There is no recognition in Regulation 132.1 of the requirements and recomendations for efficient use of energy contained in Part 8.


Insert at Regulation 132.1 below (ii)

' (iii) the efficient use of electricity'

As Energy Efficiency is the biggest change in the 18th edition wiring regulations and calls for a whole new part introduced, I think this person has a vlid point.


Regulation 801. states that the cross sectional area of conductors may be optimized to reduce losses and we think this should be mentioned here perhaps as an advisory Note!



At Regulation 132.6 insert after item (viii)

NOTE: The cross-sectional area of conductors may be increased to reduce losses as part of energy efficiency management requirements contained in Part 8 of this standard.

This comment will need a little more thinking about, in particular, how the conductor is optimised and what effect this will have on the cost of the installation. If the cost becomes too high, installers may be tempted to stick with the original calculations.

Lots more to follow will publish again soon....

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