The guy who drilled my well and installed the deep well pump, 34 years ago, installed something that looked like a big capacitor. It was a cylinder maybe two inches in diameter, 1 1/2 inches high, connected through one of the standard knockout holes of the panel. He said since his company started putting those in, plus a bare ground wire all the way down to the pump, they had no more pumps knocked out by lightning. As I recall it had two wires, one to each 120v leg, plus one wire to ground. So obviously whatever it did affected the whole house, not just the pump. Was this maybe a primitive surge protector? It did not strike me as being big enough to absorb any substantial surge, certainly not a lightning strike.