A couple of questions here too Max.
1. Why glass insulators on the lightning suppressor feeds rather than ceramic? Does the glass withstand the high voltage during a lightning surge better than ceramic?
2. Do the MOV suppressors ever fail catastrophically as did the ceramic insulators you pictured? What kind of peak currents are we talking about here during a strike?
Peak current amplitudes are in the tens of kilo-Amps. Every lightning stroke is different, and a distribution graph of peak current amplitudes shows a greater than 90% probability for a 0 to 20 kA peak, and about a 60% chance of a 40 kA peak.