ground wire in the bilge

[Tom Boyd]

While replacing the bilge pump float switch on my Hunter 336, I noticed that a #8 black ground wire had come loose. The wire is attached to the metal plate that I assume the keel is bolted to. It was no problem to repair, but then I started wondering exacting what it is gounding. I assume that it's grounding the electronics since it is only a #8 wire. I would expect that the engine/battery is grounded with a larger wire and now I'm wondering where that ground wire is. Does anyone know?

 

[Don Berger]

ground

follow the black cable(s) from the batteries. Likely only one and it's to the engineDon

 

[Rob Morton "Euphoria"]

Ground wire for lightining?

We have a 23.5 and we have a wire that connects to the keel bolts and from my understanding from the owners manual its for if you get hit with lightining that it provides a ground out through the keel. I don't know about on a bigger boat it may be the ground for electrial system like Don said.Rob Morton

 

[Bill O'Donovan]

Old wives tale

...that it's a grounding for lightening. The only solution for that is one of those metal brackets that affix to the mast and has two trailing wires to toss on either side into the water. That will deflect the blast away from the boat and electronics. Costs around $600.

 

[Sam Lust]

Baloney!

Why would anyone want to put a Mickey Mouse system like that on board when they already have a fantastic ground system already on board, namely the keel! Several thousand pounds of excelent conductor: lead or cast iron. All you have to do is persuade the lightning to follow your preferred path, mast to compression post to connector wire to keel bolts to keel. Enormous amounts of research done in Florida, lightning capitol of the world. All I would do is up-size the wire between the post and keel, (path of least resistance) making sure that if it changes direction in a gentle curve with no kinks. Electricity at that power level doesn't like to turn so you need to persuade it gently.