Arc Fault Detection

[lyledunn]

The DPC for the second amendment of BS7671 2018 is on the BSI website for public consultation. One regulation change relates to arc fault detection devices which are recommended in the current edition of 7671 but will be made mandatory if the DPC is enacted. The move is said to be being made to tackle the significant number of fires where the ignition source is due to electrical arcing in the electrical installation.
At current prices a consumer unit populated with MCBs and RCDs to meet the requirements of BS7671 will cost somewhere between ?70 and ?200. To meet the proposed change to make AFDDs mandatory, the same unit will cost somewhere between ?1000 and ?2000. No doubt costs will fall in due course but it seems a hefty price to pay for something that lacks a robust body of evidence to support the move to obligation.
I would appreciate your opinion, as would, I am sure, JPEL/64, our national wiring regulations committee.

[Fishy]

Looked at this about a year ago, with electrical engineering colleagues.  Pioneered in the US (reputedly due to their ropey standard of domestic electrical installations and massive stock of timber housing).  For various technical reasons, they give far better protection from arcing in domestic installations (the benefits in commercial installations is less clear - something to do with "extraneous bonding" which is far beyond my competence and I must confess that I stopped listening at that point).  The view was that if the regulatory drive was there, they would quickly get incorporated in 'standard' residual current circuit breakers (modification of the electronics already existing in these) and the cost would quickly come down.  It would lead to the phase-out of electro-mechanical miniature circuit breakers, which was seen as a very good thing.


https://blog.schneider-electric.com/power-management-metering-monitoring-power-quality/2013/07/03/do-you-know-an-arc-fault-detection-device-afdd-can-prevent-from-an-electrical-fire/

https://www.hager.co.uk/news-exhibitions-case-studies/18th-edition/arc-fault-detection-devices/89766.htm