What are some of the changes?

​

The most obvious change is we now have a Part 8 to BS 7671, dealing with Functional Requirements. We have a new term, the
‘prosumer’, this being both a consumer of electricity and also a provider of electricity, or in other words a small-scale
generator of electricity.

 

Requirements for bonding have been reclarified to make it clear that an extraneous conductive part that enters a building and
can introduce a dangerous potential difference must be connected to the main protective bonding system. Although this
requirement has been with us for a while now, it is clarified that utilities entering a building on a non-conducting pipe is
unlikely to require main protective bonding.

 

Arc Fault Detection Devices, recommended by BS 7671:2018 has now been clarified; for some this has been a watering down of
what is required, whilst for others it is welcomed definitive guidance.

Arc fault detection devices conforming to BS EN 62606 shall be provided for single phase AC final circuits supplying socket-
outlets not exceeding 32 A in:

• Higher Risk Residential Buildings (HRRB).
• Houses in Multiple Occupation (HMO)
• Purpose Built Student Accommodation
• Care Homes
• For all other premises, the use of AFDDs is recommended for single phase AC final circuits supplying socket-outlets not
exceeding 32 A.

 

Parts of Section 422 have now disappeared in reference to fire and difficult evacuation conditions, replaced by requirements
for Protected Escape Routes. It makes sense that electrical planning in relation to fire safety be included in the fire safety
management plan. Appendix 13 provides more guidance.

Transient over voltages due to indirect lightning strikes has also changed (again) with the owner of the installation being able
to declare that protection is not required due to any loss or damage being tolerable to equipment.

RCD test notices need not be affixed to domestic consumer units, if there is proof that the person ordering the work has been
made aware of the requirements, presumably the proliferation of labels affixed to the cover of a consumer unit has become
too much toa bare. Similarly, requirements to fit labels to warn of surge protection devices have been introduced, with similar
caveats for domestic and similar settings.

I

f you go looking for rating factors for cables in thermally insulated materials, you will no longer find it in Part 5, this has been
relocated to Appendix 4 where much of the other detail is required when determining the current-carrying capacity of
conductors and cables.

 

RCD Type AC now can only be used to serve fixed equipment, where it is known that the load current contains no DC
components, something that has been discussed for many years but not acknowledge by BS 7671.

 

When considering the cross-sectional area of a main protective bonding conductor for a site with several buildings,
clarification has now been made to confirm that the bonding conductor is selected based on the supply to that building,
rather than the supply to site.

 

Inspection, testing, and certification / reporting does see a few changes, but to the well experienced test operative this should
pose little problem.

Special installations and locations also see some changes, again nothing major for those who have kept abreast of the
previous changes and additions. Don’t get exited about the change in proximity of a socket outlet to a bath or shower, the
difference is minimal.

 

he new Chapter 8 within BS 7671 covers energy efficiency measures, the interface with the smart grid, the management of
electricity consumption, the management of renewable sources of electricity, and energy storage. This is a complex area and
this blog only mentions some of the many requirements concerning prosumers’ electrical installations (PEIs). Chapter 82
provides additional requirements, measures and recommendations for the design, erection and verification of all types of low-
voltage (LV) electrical installations. With active energy management, the end-user should be able to permanently monitor
and control his or her own electricity consumption and production. The concept of the PEI has also been developed to take
advantage of renewable sources of energy (such as solar photovoltaic (PV) and wind turbines) and energy storage. There are
different types of PEI. They include:

• individual PEIs
• collective PEIs and
• shared PEIs.

Individual PEIs are considered to be an electrical installation (for example, a private house or workshop) that can either
produce or consume electrical energy.

Three operating modes are considered for individual PEIs.

• direct feeding mode (where the installation is supplied from the grid or supply network
• island mode (where the installation is supplied from its own generator) and
reverse feeding mode (where the installation supplies electricity back to the grid or supply network).
• Collective PEIs are several consuming electrical installations connected to the same public distribution network and sharing
one common set of local power supplies and energy storage equipment.

​

Amendment 2 of BS 7671:2018 seeks to set in place the requirements for electrical installations as we move into a changing,
and unpredictable world, which it seems to have done without too much upheaval. The way in which we use electricity is
changing, and the standards that control safe design and installation need to change with the times. Electrical technology will
constantly evolve, if we can embrace the changes that come with it, we will be better placed to meet the needs of the future.