BS7671:2018, or as its more commonly known – the 18th Edition of the Wiring Regulations is effective for all new design & installation works from 1st January 2019. Whether the work is in an existing installation, or a completely new build project.
- This is for information only, designers & installers are advised to purchase a copy of BS 7671:2018 and follow the requirements & recommendations within, this information does not constitute design advice.
The scope has been extended to include an extra category (section 730 for electrical shore connections & inland navigation vessels. Section 730 contains the particular requirements for this new special location.
Chapter 46 is new and Chapter 53 has been completely rewritten. Part 6 has been restructured & the regulations for inspection & testing move to new chapters and get new regulation numbers.
Added & Amended Definitions
There are several new definitions e.g. “Departure” is a new definition, some existing definitions have been amended for clarification.
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.
Only Use Manufacturer Approved Parts
Devices & components used in low voltage assemblies such as 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, and is responsible for the assembly
Arc Fault Detection Devices
AFDDs have been added to Chapter 42. These DIN mounted devices provide additional protection against fires that are caused by arc faults in AC final circuits by detecting faults that RCDS & MCBs cannot detect.
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.
In 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 what is already common practice for RCDs & RCBOs
Also in the schedule of test results form there is a new tick box on AFDDs which allows the installer to record operation of the manual test button on the AFDDs, again this is similar to RCDs & RCBOs
Schedule of Test Results
The generic schedule of test results for domestic or similar (100A) installations has been revised. A new column is included for recording the operation of AFDD test buttons.
Other new columns include RCD operating current, maximum permitted Zs, IR test voltage. Plus the RCD trip time columns have been reduced from two to one.
Within the 17th Edition of the Wiring Regulations, the requirements of surge protection were determined through risk assessment methods.
Now, overvoltage protection must be provided in certain circumstances. For example, where there is risk of serious injury, where there is a risk of loss of human life or a large number of co-located individuals are affected, where there is an interruption to public services and where there is an interruption to commercial or 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.
Crabtree can help you comply with the 18th Edition with our Arc Fault Detection Devices... Read More
Our varied range of consumer units includes the stylish Starbreaker, which includes the finger safe... Read More