17th Edition Wiring Regulations Paperwork
Changes to Certificate and Report Forms
The new 17th Edition Wiring Regulations (BS 7671) include changes to:
- Initial verification
- Periodic inspection
- Certification and reporting
- Appendix 6 – model forms for certification and reporting
Why have these changes been made?
New wiring regulations were necessary in order to bring UK requirements in line with the International Electrotechnical Commission (IEC) and the European Committee for Electrotechnical Standardisation (CENELEC) harmonisation documents.
In Part 6, which relates to initial verification, periodic inspection and testing, and certification and reporting, the requirements are based upon Harmonisation Document HD 384.6.61 S2;2003, with reference to the more recent HD 60364–6 Part 6:2007 — Verification, and to the 16th Edition’s Part 7.
What are the main changes?
Chaptering and numbering
In the new 17th edition wiring regs, inspections and testing are covered in Part 6, instead of Part 7, bringing it into line with the European numbering system, which means that:
- Initial verification is in Chapter 61
- Periodic inspection is in Chapter 62
- Certification and reporting is in Chapter 63
- Model forms for certification remain in Appendix 6
Inspection – 611
Many regulations in 17 edition have been worded differently, which has impacted upon required items for inspection, and consequently in the model form for the Schedule of Inspections:
For example, the terms ‘direct contact’ and ‘indirect contact’ are no longer used. They are replaced with ‘basic protection’ and ‘fault protection’. ‘Basic protection’ is protection against touching live parts. ‘Fault protection’ is protection against receiving a shock from conductive parts that have become live due to a breakdown of insulation or damage to equipment.
Check 611.3 for items for inspection, and the model form for the Schedule of Inspections in Appendix 6.
Testing – 612
Most requirements for testing remain, except for:
The minimum acceptance values for insulation resistance have been raised, when measured at a distribution unit or consumer unit with all final circuits connected but with current using equipment disconnected. (All applied test voltages remain unchanged):
- SELV and PELV – from 0.25 to > 0.5
- Up to and including 50 V (apart from SELV and PELV) – from 0.5 to > 1.0
- Above 500 V – from 1.0 to > 1.0
- More stringent requirements for minimum insulation are advised, applicable to the wiring of fire alarm systems in buildings
- Phase sequence verification must be carried out in multiphase circuits.
Voltage drop – 612.14
Where necessary this can be evaluated by measurement of circuit impedance to verify compliance with 525 — voltage drop in consumer’s installations.
Various changes have been made to model forms, most notably to the Schedule of Inspections.Start of page