BS 7671 2018

[lyledunn]

BS 7671  2018 was issued 2.7.18 and will come in to force in January 2019. I am beginning to get my head around the changes some of which are fire-related and noteworthy. One such is the recommendation for the deployment of arc fault detection devices. Regulation 421.1.7 is presented as a recommendation rather than in prescriptive form. There is also a list of situations where AFDDs might be used which includes sleeping accomodation, areas with stored combustible materials and locations where irreplaceable items might be kept. Any installation designer will certainly feel the weight of the decision-making process and is likely to err on the safe side. I could see in a short period of time AFDDs becoming  as common as RCDs are at the moment.

[colin todd]

Nah , it will be like maxiskirts. Will never catch on.

[Owain]

Nah , it will be like maxiskirts. Will never catch on.

But will cost more than what it replaces

[lyledunn]

I am not particularly an exponent of the devices but as an occasional designer of electrical installations it would be reckless of me to ignore a recommendation in the national standard.
421.1.7; "Arc fault detection devices conforming to BSEN 62606 are recommended as a means of providing additional protection against fire caused by arc faults in AC final circuits". Under a note that follows the regulation there is a list of situations that might benefit from AFDD deployment, including sleeping accomodation. So if I was designing the electrical installation in say a care home, AFDDs would be on my spec!
Schneider have developed a double module unit ( twice the width of a single MCB) which combines arc fault detection in both series and parallel modes, RCD and over current protection. The initial costs will be in the order of ?120 which will quickly tumble as competition increases.
Whether they will catch on or not remains to be seen but I think it would be unreasonable from a fire safety perspective to dismiss the benefit of the incredible technology employed in these devices.