What do you do to mitigate lighting damage?

[skyhawk]

Originally Posted by carstendenmark

I wonder if this 2-pole switch will work, to shut off power to the 12V sensitive devices during a thunderstorm ?

I don't know the gap of the internal conductors when shut off, but I can split one in pieces. (Price is 2 US$ where I am now.)

Sounds like MOV's makes more damage than good, when overpowered...

Probably obvious, but I suspect the answer is 'sometimes'...or 'maybe'

Certainly if it takes a direct hit the lightning would vaporize the thing and keep going....
but
based on my lightning story posted earlier I think anything like that is probably worth doing.
(* basically the short of it was a direct hit to an antenna. Two independent windshield wiper motors one switched on the other switch off at the time of the strike. The one off was fine the one on was melted. Ditto for every light circuit or a any other thing in the boat. Things things were simply switched off with their little operational on-off 12VDC toggle switches, nothing more)

I still sorta like my idea of an e-stop button somewhere easy to get to and a bunch of relays to instantly disconnect every critical circuit in the boat... if it starts getting too loud outside it would be quicker than running around disconnecting everything.

[fritzthecat]

Originally Posted by a64pilot

Insurence
But it’s not a sure thing, I’d bet that those that have been struck are a minority,or insurence wouldn’t cover it, you would buying special high dollar lightning insurence if it were that common.

I connected my shrouts to earth plates mounted underneath the waterline close to the shrouts, the connected them in the boat with strong 2AWG Copper cables. On top I swoped the plastic wheels of the anchor chail leaders to steel and on anchor the whole rigging gets grounded well and the potential of getting hit deminishes

[calmissile]

Originally Posted by Sailmonkey

That “Lightning” looks an awful lot like primacord running down the shoreline to initiate some explosives beneath the surface.

You nailed it.

[Sailmonkey]

Originally Posted by calmissile

You nailed it.

Done it a handful of times myself.

[Paul L]

Originally Posted by skyhawk

Probably obvious, but I suspect the answer is 'sometimes'...or 'maybe'

Certainly if it takes a direct hit the lightning would vaporize the thing and keep going....
but
based on my lightning story posted earlier I think anything like that is probably worth doing.
(* basically the short of it was a direct hit to an antenna. Two independent windshield wiper motors one switched on the other switch off at the time of the strike. The one off was fine the one on was melted. Ditto for every light circuit or a any other thing in the boat. Things things were simply switched off with their little operational on-off 12VDC toggle switches, nothing more)

I still sorta like my idea of an e-stop button somewhere easy to get to and a bunch of relays to instantly disconnect every critical circuit in the boat... if it starts getting too loud outside it would be quicker than running around disconnecting everything.

Do you think the coils in those relays are not going to be effected by the EMP from the high voltage strike? EMP is Electro Magnetic Pulse.

[skyhawk]

of course they might.
I'm just saying that anecdotal evidence suggests that turning everything OFF in some circumstances can maybe be helpful, so it seems to me that a good way to turn everything off is probably worth considering as part of a mitigation plan

[LakeSuperior]

FWIW a lightning strike is a pulse and the EMF associated with the pulse will contain a continuum of EM wavelengths. Consequently, there can be no gaps in the Faraday cage.

Also, the Faraday cage does not protect the electronics from the magnetic component of the pulse. The magnetic pulse can induce enough current in the electronics to fry them.

As one poster mentioned it is not practical to mitigate EMF pulse damage.

[Paul L]

Originally Posted by LakeSuperior

FWIW a lightning strike is a pulse and the EMF associated with the pulse will contain a continuum of EM wavelengths. Consequently, there can be no gaps in the Faraday cage.

Also, the Faraday cage does not protect the electronics from the magnetic component of the pulse. The magnetic pulse can induce enough current in the electronics to fry them.

As one poster mentioned it is not practical to mitigate EMF pulse damage.

I guess it depends on what you mean by 'no gaps'. If you mean no visible gaps, then that is not accurate. The gaps need to be small enough to block the wavelength of the fields that have enough energy to do damage to the protected electronics. Large faraday cages used in research and development are often called screen rooms, as they are built with enclosing screens - holes and all.

Faraday cages do offer protrction from EMP.