Wiring Regulations BS7671
18th edition with blue cover, published in July 2018 and applicable from 1 January 2019.
This video and the text below cover the main changes in Part 6 - Inspection and Testing.
The main change in Part 6 is that the entire content in chapters 61, 62 and 63 has been removed. Two new chapters have been added, with 64 containing content previously in 61, and 65 being the equivalent of the old 62. Content previously in Chapter 63 has been divided and added to the end of both 64 and 65.
While much of the content is unchanged other than it's location within the chapters, there are various smaller changes and these are described in the video and the text section below.
BS7671:2018 18th Edition Part 6 Changes
Printed book available from Amazon. When purchasing, note that many older editions are still available, these have different coloured covers.
Changes in Chapter 64
Previously Chapter 61
- 642.3 (iii) routing of cables in 'safe zones' changed to 'prescribed zones'
- 642.3 (viii) (c):
- (iv) additional item 'exposed conductive parts are connected to the earthing arrangement'
- (xvii) new, selection and erection or wiring systems
- (xix) new, selection and erection of suitable SPDs where required
- (xx) new, measures against electromagnetic disturbances
- 643.2 Continuity of conductors:
- reworded, previously title included 'main and supplementary bonding', now content includes 'connections to exposed conductive parts and extraneous conductive parts'
- tests for protective conductors and ring final circuit conductors added as (i) and (ii)
- requirements for test voltage/current removed (previously 4-24V o/c and 200mA)
- separate regulation 612.2.2 'continuity of ring final circuit conductors' removed
- 643.3.2 Insulation resistance:
- FELV testing added under table 64, this was previously separate in 612.3.4
- FELV test wording also refers to using the same test voltage as that applied to the primary side of the source
- Notes and some other text rearranged, some notes combined with the main text
- added 'when measured values show evident differences between circuits, further investigation is required'
- old 612.4.5 deleted (basic protection by a barrier or enclosure provided during erection)
- 643.6 Polarity:
- now includes a test at the origin where relevant and before the installation is energised
- addition of sentence 'where single pole switching devices are not permitted in the neutral ...'
- (iii) amended to 'wiring has been correctly connected throughout the installation', previously 'connected to socket outlets and accessories'
- 643.7.1 General:
- (a) (2) note added 'see table 3a in appendix 3' which contains trip times for various RCDs
- added paragraph starting 'where the effectiveness of the protective measure has been confirmed ...'
- (b) (2) added 'other appropriate methods' for verification of overcurrent protective devices
- (b) (2) note added 'see table 3a in appendix 3' which contains trip times for various RCDs
- (c) content expanded with more detail, although the procedures have not changed
- 643.7.3 Earth fault loop impedance:
- addition of carrying out an electrical continuity test before EFLI testing
- addition of measured EFLI shall comply with Chapter 41
- addition of 'where not satisfied ... and supplementary bonding provided ... bonding shall be verified
- 643.8 note regarding RCD disconnecting within 40ms added, sentence regarding supplementary bonding complying with Chapter 41 added
- 643.9 phase sequence check must be done 'at all relevant points of the installation', previously unstated
- 643.10 Functional testing expanded with examples of specific equipment, and manually operated test facility of any installed AFDDs
- 643.11 Voltage drop - condensed significantly, although the intent is similar
- 644 Certification for initial verification - previously in Chapter 63, this is substantially similar, although all rewritten/rearranged
Further details on testing and inspection will be covered in a subsequent article in this series on Appendix 6.
Changes in Chapter 65
Previously Chapter 62
- 651.2 Periodic inspection:
- (iii) new, confirmation of correct setting and rating of protective devices
- (iv) new, confirmation of correct setting and rating of monitoring devices
- Note 2 new, existing installations confirming with earlier editions of BS7671
- Addition of text regarding RCM and IMDs
- 653.2 Addition of a specific list of items to include on the report.
- 653.4 Specific requirement for a recommended interval until the next inspection and an explanation for the recommendation.
