The BS7671 Regulations for the selection and erection of wiring systems (impact) will be redrafted.
It will be a requirement that cables that are concealed in a wall or partition (at a depth of less than 50 mm) are protected by a 30 mA RCD for all installations if other methods of protection, including the use of cables with either an earthed metallic covering or mechanical protection, are not employed.
The exception for cables that form part of a SELV or PELV circuit will be retained.
Section 557 Auxiliary Circuits
A new section, Section 557 of BS7671, covering auxiliary circuits for low voltage electrical installations will be included, although auxiliary circuits for fire and intruder alarms, traffic lights, etc (where specific standards exist) are excluded. This is a completely new section. The current requirements for auxiliary circuits in BS 7671:2008+A2:2013 are given in Regulation 537.5.3.
Section 717 Mobile and Transportable Units
In 2008 Section 717 of BS7671 was introduced, which provided requirements that were applicable to mobile or transportable units.
New Regulations being introduced by Amendment No. 3 include:
Regulation 717.413 the use of electrical separation as a protective measure (based on the latest CENELEC HD)
Regulation 717.551.6 where a generating set is used as a switched alternative to the normal supply
Regulation 717.551.7.2 where a generating set is used to operate in parallel to other sources
Changes will be made to the figures that show examples of connections associated with the mobile or transportable units.
Sections 559, 714 and 715: luminaires and lighting installations
In 2008 additional requirements for general lighting were included in BS 7671.
Amendment 3 will introduce a number of notable changes to align the requirements of BS 7671 with the both latest IEC and CENELEC standards.
Chapter 41 Protection Against Electric Shock
This Regulation will require, in accordance with Regulation 415.1, RCD protection for socket outlets up to 20 A (and for mobile equipment up to 32 A for use outdoors) for all installations.
There is, however, an exception for RCD protection (for socket outlets up to 20 A) for a specific labelled socket outlet or where a documented risk assessment determines that RCD protection is not necessary in Regulation 411.3.3.
Maximum earth fault loop impedances given in Tables 41.2, 41.3, 41.4 and 41.6 will be revised to take into account the Cmin factor given in CLC/TR50480:2011.
Cmin is the minimum voltage factor to take account of variations in voltage, depending on time and place, changing of transformer taps and other considerations. The notes to the Tables will be changed to reflect maximum permitted operating temperature. In addition, Regulations 411.5.4 and 41.6.4 will include a Cmin factor.
Chapter 42 Protection Against Thermal Effects
Regulation 421.1.200 has been introduced and will require switchgear assemblies, including consumer units, to have their enclosure manufactured from non-combustible, or not readily combustible, material, or to be enclosed in a cabinet or enclosure that is constructed of non-combustible, or not readily combustible, material.
Appendix 6 Model Forms for Certification and Reporting
Appendix 6 contains the electrical installation certificate, the minor works certificate and the electrical installation condition report (used for reporting on the condition of an existing electrical installation) as required by Part 6 of BS 7671.
Electrical Installation Condition Report
Amendment 3 will make changes to the electrical installation condition report and associated notes, including a requirement to carry out an inspection within an accessible roof space where electrical equipment is present in that roof space.
Amendment 3 of BS7671 will also make a significant change to the certification of new work: the schedule of inspections (for new work only) has been replaced by examples of items that require inspection during initial verifications (which must be appended to the electrical installation certificate).