Synergy Electrical are now fully compliant with the new BS7671 2018 Wiring Regulations:
The 18th Edition of the BS7671 Wiring Regulations has been finalised by the IET and will be issued on 2nd July 2018. It is set to supersede the previous 17th edition on 1st January 2019 and contains multiple changes, although not all of these are pertinent to test and measurement.
RCD Protection The 18th Edition is characterised by increased prevalence of protective RCDs in a range of installations so there will be greater need for RCD testers and MFTs with a reliable RCD testing function. In particular, <30mA RCDs will now be a requirement on sockets rated up to 32A (unless deemed unnecessary by a risk assessment) rather than just 20A (411.3.3), whilst they will also be needed on all AC final circuits supplying luminaires within residential buildings (411.3.4). It is also important to note that Table 41.1 now applies to final circuits rated up to 63A (with sockets attached) so maximum disconnection times will apply to a greater number of circuits, thus requiring accurate testing with appropriate equipment. Switching and Isolation The new Chapter 46 of the 18th Edition Wiring Regulations discusses non-automatic local and remote isolation and switching when these measures are used to prevent or remove dangers associated with electrical installations and equipment. It also deals with switching used to control circuits and equipment although any circuits or equipment that come under BS EN 60204 are solely covered by that standard. Further changes have been made in chapter 56 which deals with protection, isolation, switching, control and monitoring. Earthing Systems There are several changes to earthing systems contained within the 18th Edition. Newly introduced regulations 542.2.3 and 542.2.8 define new requirements for earth electrodes whilst two further regulations (518.104.22.168 & 522.214.171.124) cover the installation of switching devices in protective conductors. The latter section refers to protective conductors in installations supplied by multiple power sources. Overvoltage Protection One of the most significant changes in the 18th edition is the overhaul of Section 443 which deals with overvoltage caused by atmospheric conditions, i.e. lightning. Where the need for protection against transient overvoltage used to be defined by the AQ criteria - effectively considering the frequency and likelihood of lightning strikes - these have now been replaced by criteria considering the potential consequences of lightning strikes. This will expand the scope where protection is required, except in certain single dwelling units, and once again these additional systems will need to be thoroughly tested. Specialist Installations Various specialist installations have been introduced into the scope of BS7671 whilst the regulations surrounding others have been modified. Of particular note to test and measurement, there will be new requirements for electrical installations in caravan/camping facilities (Section 708); installations in caravans and motor caravans (Section 721); and electric vehicle charging points (Section 722). A particular requirement for B-type RCDs in charging points and a repeal of exemptions for PME supplies are important and may require updated equipment. Floor and Ceiling Heating Systems Section 753 has been revised and now deals with all embedded electrical systems for surface heating. In addition to heating, other applications such as de-icing and frost prevention are now included within the section and both indoor and outdoor systems are considered.
Part 1 Scope of the regulations now includes shore connections for inland navigation vessels. Moving walkways and escalators are specifically excluded.
Where equipment is used outside the scope of it's standard, this must be recorded on the electrical certificate as specified in Part 6.
Part 2 Around 20 new definitions with a small number of amendments. Discrimination is now Selectivity.
Part 3 Substantially identical. Only a few very minor changes here, most of which are a result of changes elsewhere.
Part 4 Part 4 contains a number of significant changes and additions. Some of the more substantial changes include:
RCDs are required for all lighting circuits in domestic premises.
Disconnection times now apply for socket outlet circuits up to 63 amps (previously 32A).
Table 41.2 now includes values up to 63 amps.
The exception for a labelled socket outlet not having an RCD has been deleted.
RCDs are required on all socket outlets up to 32 amps (previously 20 amps).
Arc fault detection devices are recommended (but are not compulsory).
New section 419, where automatic disconnection is not feasible.
Section 443 changed significantly and expanded, including a new Annex B443.
New Chapter 46 on isolation and switching.
All wiring systems must be supported by fire-resistant fixings. Previously this applied only to wiring installed in escape routes.
Most of the required warning notices are printed in a much larger text size - those actually used will need to have this larger size.
Chapter 53 has been completely revised, covering protection, isolation, switching, control and monitoring.
Two new regulations regarding earth electrodes.
Chapters 61, 62 and 63 have been deleted, and replaced with new Chapters 64 and 65. The old Chapter 63 (Reporting) content has been added into both the new 64 and 65.
Several minor changes to testing, including specific mention of AFDDs.
New section on RCMs and ICMs.
Part 7 Most of Part 7 contains minor amendments. More substantial changes include Section 722 Electric Vehicle Charging and Section 753 Heating Cables.
A new Section 730 covers onshore units of electrical shore connections for inland navigation vessels.
Appendices Many minor changes here, including updated references to many other standards.
Appendix 6 (model forms for certification and reporting) has a number of changes, including extra columns on the model schedule of test results for insulation resistance test voltage and AFDD test button operation.
Appendix 14 (earth fault loop impedance) has been relocated into Appendix 3. Appendix 14 now covers prospective fault current. A new Appendix 17 covers energy efficiency when designing and erecting electrical installations.
Extended ScopeThe scope has been extended to include an extra category (section 730 catering for electrical shore connections & inland navigation vessels). Section 730 contains the particular requirements for this added special location. Chapter Changes Chapter 46 is new and Chapter 53 has been rewritten. Part 6 is restructured & the regulations for inspection & testing move to new chapters and get new regulation numbers. DefinitionsThere are several new definitions, and a few existing definitions that have been amended. For example, “Departure” is a new definition. Departure is explained as an intentional decision to not fully comply with BS7671.This must be accompanied by a declaration from the designer that the safety levels achieved are not less than full compliance with BS7671 would provide. Energy Efficiency A new appendix on energy efficiency is included within the 18th edition. Appendix 17 makes recommendations for the design construction & assembly of the installation for optimising efficiencies in the use of electricity. Only Use Approved PartsDevices & components used in low voltage assemblies e.g. Consumer Units, Distribution Boards etc. shall only be those that have been declared suitable for that purpose by the manufacturer of the assembly. If in doubt ask the manufacturer of the assembly to confirm compatibilities. Note; if a deviation from manufacturer instructions is introduced then the person introducing the deviation becomes the manufacturer. Arc Fault Detection DevicesAFDDs have been included in Chapter 42. These devices provide additional protection against fires that are caused by arc faults in AC final circuits. Arc fault detection devices (when used) should be installed at the origin of each final circuit that is are being protected, AFDDS should be installed in consumer units and/ or distribution boards. Discover more about Arc Fault Detection Devices here. Appendix 6In the schedule of inspections, under the section dealing with consumer units & distribution boards there is a reference to check for the AFDD six monthly test notice, similar to the requirements for RCDs & RCBOs. Also in the schedule of test results form there is a new tick box for AFDDs which allows the installer to record operation of the manual test button on the AFDDs, again this is similar to RCDs & RCBOs. Surge ProtectionWithin the 17th Edition of the Wiring Regulations, the requirements of surge protection were determined through risk assessment methods. Now, overvoltage protection is required in certain circumstances. For example, where there is risk of serious injury or of loss of life, where many co-located people are affected, where there is an interruption to public services, or commercial / industrial activity. Other requirements are contained in 443.4. For circumstances where overvoltage protection is not required, a risk assessment can be carried out. If a risk assessment is not carried out, overvoltage protection must be provided. You can find out more about surge protection here. Get the lowdown on the 18th EditionLooking to get more pointers on the 18th Edition? From Arc Fault Detection Devices, Transient Overvoltage Protection to RCDs, we've got you covered. Visit our 18th Edition Area and check them out.