Lightening ground wire

[John Larsen]

Have found white wire, approximately 8 guage, connected in ceiling of cabin to mast bolt. The other end runs through cabin wall and down into bilge compartment under floor. However, the 12" exposed wire under floor has been broken and I can't seem to locate where it was connected. My assumption is that this is a ground wire for lightening which somehow runs to keel and protects against lightening strike. Would like to find out where this gets connected before I get hit by lightening and boat blows apart like seen on TV..ThanksJohn Larsen

 

[Hardy Scroggin]

White ground wire

I believe that what you are seeing is indeed a ground wire and is connected to one of the keel bolts in the bilge.

 

[Big T]

Ground

Mine is connected to my centerboard pivot bracket ensuring definite discharge to ground (water). If you have a fixed keel, It was probably connected to that.

 

[Marcie Robson]

ground wire

On my h25 it has a very large wire (cant remember the gauge) larger than anything else used on the boat and solid copper... not always a good idea to go by insulation color because that can change.... anyway its attached to the keelbolt closest to the mast post on the salon side of the bilge access area .... im not sure of the method of securing it because the keel bolt sealant covers it up......as a very temporary (better than nothing) you can attatch it between a second bolt and the one allready there using a bolt of the same metal thats allready in use to prevent a reaction between the two (mines stainless) and then check around with the marinas .... im sure theyve pulled a keel or two and probably know the way it should be secured ..... also a little fyi I was told never paint the bottom of the keel because thats how the mast dissapates the current from the strike, but that could also be because it looks impossible to do anyway....

 

[Chris]

wire won't help

Guys, I hate to say that, but if your boat gets hit, that little wire won't do you any good anyway.... Cruising World had some good articles on protecting the boat from a lightening strike and the size wire it requires to protect it is unreal. Think about it, your looking at millions of volts going through that wire, anyone wants to estimate the amperage?I'm not sure why that ground wire is there, but it won't do you any good if you get hit by lightning.....Regards,Chris

 

[Dick Leis]

Size non-ctitical

Contrary to the comments made by Chris, the size of the ground wire is not that critical because the theory of lightening protection is to prevent it first. To do this, you must dissapate the electrical potentional that exist between the sky and ground. By grounding the mast in some manner, the charge is slowly bled off, at least locally, and the big bolt is prevented. I would think it prudent to run as large a wire as practical without going overboard.