Wow. I am certainly glad the entire building did not burn. Just before I turned 16, in 1988 the home I grew up in near Mukwonago, WI was struck by lightning. I don't recall electrical damage, but I do remember a burned outlet. TV fried, touch base lamps shorted and junk. Were told it was a
"cold bolt" or the house would have gone up. 26,800 volt power lines in back yard.
Certainly not the first time there have been lightning strikes at IRM. Every summer we suffer some from of damage or see evidence of strikes. There are lightning arrestors in many spots on our 600 volt overhead, but perhaps you can never have enough. Much of the high voltage AC system has lightning arrestors and you will note they sustain damage in any strike.
But I think this is the first time a building has been involved with such extensive and serious widespread damage.
Discussion continues since the new 600 volt DC safety switches bring the DC overhead power inside each building, even when the 600 volt inside the building is not energized. That can provide another path to ground through those cabinets and switchgear mounted a few inches from the building's metal skin. Does this help or hurt?
Bob Kutella