Electronic – Voltage drop-out after lightning strike


A powerful thunderstorm rolled through my area yesterday and something happened that I had never noticed before. Many times before when powerful thunderstorms with lightning rolled through, the AC mains power has either not been affected or went totally out after a nearby strike. Yesterday something different happened…

After a very bright and loud (and most likely nearby lightning strike, but not sure where it could have hit), the AC mains dropped out (to zero I guess) and stayed out for about 5 seconds then came back ON…. What could have caused this? I am fairly certain there are no grid substations too nearby where I live. Furthermore, I guess to answer this question, we have to assume that my small city uses the most common or "default" type/method of electrical power distribution.

Best Answer

The circuit breakers used in power distribution often have a feature called a "recloser", which will make some number of automatic attempts to reclose the breaker after a fault, in order to deal with transient problems such as nearby lightning strikes.

In this case, the strike didn't cause a permanent short circuit, so the recloser was successful on its first attempt.