AFDD - Arc Fault for dc Solar MGs

[robint]

hi  Guys
The latest Amd 2 of the 18th IET Regs has the hots for AFDDs. Sure we all know how these work dont we?  A little Arduino Nano filters the the ac current for signs of high freq arc noise (naturally the Big Corps want to keep it all secret - but we can know all about RCD workings and their problems with dc levels saturation and spike damage - which is why they have a test button)
Draw you own conclusions on this expensive addon £60-80 for your rack. 

But I am here to address the Solar dc needs.  We can maybe assume that the AFDD doesnt work on dc (indeed to work at all it needs ca 180mA load obviously?).  The ever helpful Trade Press noted it cant protect on faulty ring circuits so leccies are in no fear of being replaced by this AFDD AI 

Pay attention at the back  - It seems to me that Solar panels are prone to arc faults from wiring, connectors, heavy bird impact, cellular shorts et al. So this might show it self as noise current. If one used one of those small current transformers and listened via an amp to the circuit might on hear the characteristic squishing noise of an incipient arc?  Would the Inverter input noise drown it out?

Just a thought guys, I havent got the means to look myself, perhaps someone else might.

Who knows this might be a useful audible warning . Im not suggesting this becomes an automatic disconnect device - thats another level of potential nuisance.

Anyone care to help?
Robin