Quote:
Originally Posted by Garyh
No pet insurance on our policy but that might be a good idea?
Well there was no surge through the mains, more like a electromagnetic induced spike from the nearby strike. Everything plugged in the mains in the obs was fine, well except the house. VCR up and running with a new fuse but the ceiling fan (IR remote unit was toasted) and have put in a new fan this arvo.
I remember a few years back at my other property there was a big storm and I was leaning against my aluminum caravan when lightning struck a tree a few hundred metres away and boy did I get a shock from the van! Made my arm tingle for some time afterwards. Killed the Caravan fridge but! Strange stuff is that lightning in what it kills and what it misses..
Ric,
I think you might be better off having a good earth stake maybe connected to the observatory roof (if metal) to take it to ground and have good foil insulation also grounded?.
Also have those earth leakage breakers and a surge board. I don`t think you can do much more than that? but they are all quiet useless with a direct strike.. 
Thanks guys for your thoughts...  |
I had a similar experience once when fishing on Nobby's for jewy when a violent storm cell passed overhead - lightning zapping everywhere , so I laid the rod down while sheltering with a couple other fishos under the big wooden beakon tower , and sat next to rod with the line between my fingers , there was a lightning strike in the water in front of me only about 30m away , scared the crap out of me and I got a jolt of current up the line - felt like someone had hit me on the ends of the fingers with a hammer. Dropped the line quick smart.
Yes a nearby lightning strike can produce strong induced transients in metal and other conductors. Can also do nasty things to sensitive electronic circuits too.
Not sure what practical measures you can take to prevent induced transients in the field though. Been a while since I did that course (Elec3230) and not sure where Betz's lecture notes are.
I vaguely remember that snubbers and clamp circuits are beneficial in protecting against such transients. The problem is large induced transient inductive currents in stray loops in the circuits which is what damaged your stuff I think (not a lot you can do there - it's to do with the actual geometry and layout of the circuit).