Re: [electricboats] Grounding.

The lightning problem is fairly easy to deal with when you have a steel or alu boat.

For GRP and wooden boats, the setup depends of the mast and keel material.

If the mast is wooden and the keel is with stone ballast, the setup must be different, with a cable from the mast top to a metal plate outside the hull.

I'm lucky to have a GRP boat with alu mast and steel keel.

The main connection must then be a heavy sized cable from the mast foot to one of the keel bolts.

If the cable and connections are sized well, the chances of the lightning will whizz around to other parts are minimal, in my opinion.

So I will do that, next time my mast is off.

The probability that a lightning will hit anything else than the mast top (the nearest conductive material to the cloud) is almost none, if the conductive path is sufficient for all the lightning power to pass through.

Again, this is just my opinion. It is based on land construction protection systems.

A steel chimney or a bridge pylon never gets burned on any of its parts, neither does the electronics attached to it, even when hit several times a year. It is WELL protected.

We can learn from the construction engineers, who has a source of more than 150 years of experience.

Carsten

On Wednesday, 9 December 2020, 12:49:00 GMT+8, john via groups.io <oak_box=yahoo.com@groups.io> wrote:

The only thing that is a "given" is that lightening protection is not a clearly understood science.

Myles might be fine with his jumper cables - it just depends on how close and how direct a hit.  And if he's lucky and stays in the marina (away from Florida and Lake Michigan) when the weather is bad, his chances are MUCH better still.

Nevertheless - if he (or any of us) gets hit, with the jumper cables in the water - I'd still bet he'd lose most of his electronics.  If he's lucky, he'll make it home to tell the tale.  Though his beard (if he has one) might be a touch singed too...  <grin>

John

On Tuesday, December 8, 2020, 08:33:36 PM CST, Carsten via groups.io <carstensemail=yahoo.com@groups.io> wrote:

Please see attached table from DPWH Standard Spec 1109, Philippines.

That's their recommendations for a reliable ground cabling size for lightning protection of masts and constructions.

Myles, I guess that your jumper cable is not that size.

So your cable might only guide some of the lightning power away.

The remaining power will surely find another way, thus burning off your electronics, batteries, etc.

On Wednesday, 9 December 2020, 03:56:41 GMT+8, Myles Twete <matwete@comcast.net> wrote:

I have a jumper cable onboard…easy to throw one end overboard on that rare 1x/3yrs that I'm out on my boat, outside the covered marina in an active storm. J