Thank you for your kind replies.
FRW, This time of year, mid-winter, there's not much for the spiders to eat.
The relay thing sounds possible especially as its blowing to ground.
I have 12 strings of 4off 12v batteries, giving me 48v at 1300ah. They are all gel types. I am used to connecting stuff in and out with cobwebs about, but it seems that the OzInverter, on a re-start, does something bizarre on the negative side to ground.
Cobwebs do collect a little dust, but so strange to se them light up like that.
Thanks MS, that's what I thought initially, so I checked and checked, but couldn't find anything obvious, and as I said the system is and was running normally.
Hydrogen, possible as the nearest battery to the cobwebs, even though Gel, could still gass.
Just odd to watch a continuse light from one end to the other, and not just a blow in the middle.
bj, Try a OzInverter on a battery bank, oztules reckons at start up "there is serious splat material".
My cobwebs do collect dust, can hydrogen form/or stay on cobwebs, how much dust ?