Sunday, July 1, 2012

Amendment 1 to the 17th Edition of the Wiring Regulations BS7671

Electricians may find this article useful as a reference to the 17th edition Amendment 1 changes to the UK Wiring Regulations BS7671.

The Electrical Wiring Regulations BS7671 now includes Amendment 1 to further harmonize with the European electrical IEC and CENELEC HD60384 standards. The Amendment 1 requirements came into effect from the 1st January 2012.

The main changes to the regs consist of:

A new numbering system
A new Section 444 for measures against electromagnetic disturbances and
Surge Protection Devices
Part 5 covering Prefabricated Wiring Systems
Part 6 introducing the new Electrical Installation Condition Reports
Part 7 includes new Special Locations for Medical and Operating and
Maintenance Gangways
Additional Appendices relevant to the latest changes
New Numbering System

The new regulation numbering system ending in 100,101 etc. has been introduced for 'UK only' national regs. For example regulations such as 553.1.100 regarding shuttered socket outlets would apply to the UK only.

Electromagnetic Disturbances

The new section 4, with details in Section 5 for SPDs (Surge Protection Devices), covers sensitive equipment that may be damaged by surges such as overvoltages and lightning strikes.

Prefabricated Wiring

Prefabricated wiring systems which are intended for permanent connection are covered in Section 5. Cables installed in ceilings and floors should be run to avoid damage from contact with building materials. Also all connections and terminations must be accessible for inspection and testing unless they are of a maintenance free type.


The biggest change to the 17th edition affecting many electricians is the new Electrical Installation Condition Reports. The EICRs are now to be used for compiling and submitting information in place of the old type Periodic Inspection Reports. The purpose of the EICR is to improve the standard of periodic reporting and make the reports easier for consumers to understand. The results of inspections have been given new observation codes and the schedule of inspections has been revised.

Additional Special Locations

Part 7 includes new Special Locations for Medical (710) and Operating and Maintenance Gangways (729). Medical locations is now segregated into 3 zones which are determined by the medical procedures to be carried out. The gangways section sets out the minimum distances between equipment such as switchgear and the fabric of the building.


Amendment 1 includes 16 Appendices which reflect the additional content. Content from Appendices 11 and 12 has been moved to Appendix 4 Current Carrying Capacity and Voltage Drop.