Let's say there's a socket and an appliance is plugged into that but the electrical connection to the socket is cut-off using a switch.

so there's a air gap and this should act as insulation and I need not to be concerned about lightning strike on the electrical line.

But there's a common sense to unplug during thunderstorm but I don't see any reason why should we do that because there's an air gap and no way electricity surge from the lightning strike is gonna jump through the air.

Someone help me understand this.

  • 1
    It already jumped kilometers from the cloud to the ground. Then the return stroke (what you see if not using fancy optics) jumps the same distance back to the clouds. Your switch air gap is not very big at all from lightning's point of view.
    – Ecnerwal
    Commented Aug 26, 2023 at 1:22
  • So there's a chance lightning spiked current might jump the gap
    – King
    Commented Aug 26, 2023 at 1:55
  • Please see past answers carrying the surge-suppression tag.
    – keshlam
    Commented Aug 26, 2023 at 2:06

2 Answers 2


Have you seen lightning? Lightning is no respecter of air gaps.

Also lightning surge currents may flow on the neutral and earth conductors. and a tyoical switch may not break neutral, and will not break earth.

  • 1
    Ok you mean to say the lightning surge current may flow on neutral line ? when the lightning strikes the overhead power lines ? and switch creates air gap only for Hot line so the electricity will still flow ? right
    – King
    Commented Aug 26, 2023 at 2:02
  • The current fans out across the surface of the earth and prefernatially flows in conductors, but it can jump small gaps. this can still cause damager even when it didn't initially hit power lines.
    – Jasen
    Commented Aug 26, 2023 at 3:14
  • 1
    it will often help, nothing will protect you if the strike is close enough.
    – Jasen
    Commented Aug 26, 2023 at 5:42
  • 1
    @King The word "surge" in surge protection is NOT lightning. Lightning is a little bit more than an electric surge. Look at the rated surge protection that it offers. It'll say something like "maximum 1000v" or something like that. Lightning is about 300 million volts.
    – Nelson
    Commented Aug 26, 2023 at 7:46
  • 1
    "MOV" (MOT is a device to create high voltage)
    – Jasen
    Commented Aug 29, 2023 at 1:34

There is a huge air gap between the cloud an ground,

That does not stop the lightning.

Unless you have a lightening rood that might save you, unplug

  • Good analogy :) lol got it
    – King
    Commented Aug 26, 2023 at 1:56
  • I've spent over 40 years on this earth and not unplugged a single thing during a storm, and I have yet to see one get destroyed. I highly suspect unplugging your stuff makes almost no difference.
    – Nelson
    Commented Aug 26, 2023 at 7:47
  • 1
    @Nelson I am the same way plus a bit longer. I do think it does depend a lot on the location a lot more than it has not happen to you and I. Depending on the stuff(cost) unplugging is decent option for some people. An air gap of feet is better than one of 1/2 inch.
    – crip659
    Commented Aug 26, 2023 at 10:56
  • @crip659 - that makes sense
    – King
    Commented Aug 26, 2023 at 11:09

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