On 31/07/2018 10:56, Andy Burns wrote:
wrote:

RCDs are to some extent sensitive to arcing as they fail to balance
the currents correctly at the high frequencies arcs contain. AFDDs
are just RCDs/RCBOs with less hf filtering.
I read that (some?) AFDDs use microprocessors to recognise the signature
of an arc.

Indeed. Bloody complicated. See eg the (promotional!) Beama Guide to
Arc Fault Detection Devices (AFDD)

http://www.beama.org.uk/asset/D6E1ED...CA85BA77DEC2B/

What I've not seen is how they are tested after they are installed.


--
Robin
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