The wiring schematic on my boat shows a lightning ground of the mast to one of the bolts that hold the keel. This seems like a really good idea, but I am not so sure that the ground was restored after the mast was removed then reinstalled. The mast dresses through an opening in the cabin roof, then fits over a step that is bolted to the cabin floor. There is no real fastening of the mast to the floor step, the stays hold the mast down. The keel is bolted to the hull with 5 or 6 large studs of approximately 1 inch diameter, below the floor, accessible through a removeable plank in the center of the floor. I have not seen a ground cable or any sort of electrical connection between the mast and the keel. The mast/boom/etc. are manufactured by Kenyon. If anyone could say what to look for, or if there is typically some concealed grounding, I would appreciate it. I'd really like to be sure that the ground path is intact.
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grounded
You don't say what the manufacture of your boat is but all of the reputable factory boats have a grounding system of some sort to the keel. On my O'day the chain plates, engine, fore stay, aft stay and mast are all connected with what appears to be copper tube of about 1/8" in diameter. It may just be a heavy wire but it feels hollow. All of the system runs to the keel creating a full grouded cage which includes the stantions and pulpits. As I said the material is not insulated and appears tube like. If your boat isn't like grounded to the keel then it may all be attached to a grounding shoe which is a copper mass made up of tiny copper pellets pressed into an oval shape and bolted through the hull. It is a very efficient dissapator (is there such a word?) of electrical energy. Good luck in your search. Mike
You don't say what the manufacture of your boat is but all of the reputable factory boats have a grounding system of some sort to the keel. On my O'day the chain plates, engine, fore stay, aft stay and mast are all connected with what appears to be copper tube of about 1/8" in diameter. It may just be a heavy wire but it feels hollow. All of the system runs to the keel creating a full grouded cage which includes the stantions and pulpits. As I said the material is not insulated and appears tube like. If your boat isn't like grounded to the keel then it may all be attached to a grounding shoe which is a copper mass made up of tiny copper pellets pressed into an oval shape and bolted through the hull. It is a very efficient dissapator (is there such a word?) of electrical energy. Good luck in your search. Mike
It's a Spirit
Mike, Thanks. It's a Spirit 28, hull manufactured by Glastron in Austin in the 70's, and the rest of the components integrated by Spirit. It all seems good design and quality, but this boat has been kicked around some, the mast was unstepped when I partnered into the boat. The schematic shows a lightning ground on the mast, being bolted to one of the keel mounting studs - it is a fixed keel. I've seen no cable or conductor separate from the mast which is of course aluminum. I'll look a little closer for grounding features this weekend. Thanks again, Anthony Drake.
Mike, Thanks. It's a Spirit 28, hull manufactured by Glastron in Austin in the 70's, and the rest of the components integrated by Spirit. It all seems good design and quality, but this boat has been kicked around some, the mast was unstepped when I partnered into the boat. The schematic shows a lightning ground on the mast, being bolted to one of the keel mounting studs - it is a fixed keel. I've seen no cable or conductor separate from the mast which is of course aluminum. I'll look a little closer for grounding features this weekend. Thanks again, Anthony Drake.
It can be done
Anthony: If you don't discover any grounding system then it really is pretty easy to do it your self. Using bare cable (copper would probably be best) simply join all of the stanchions, chain plates, engine, mast and both pulpits to one of the large keel bolts or a grounding shoe. It need not be fancy and you'll have to find a way to connect the stanchions below deck but you'll have a safer boat in the end. As I said my system is bare, heavy, single strand wire. I don't know wire measurement but mine is about 1/8" or a little less in diameter. Regards, Mike Glover Pitterpat
Anthony: If you don't discover any grounding system then it really is pretty easy to do it your self. Using bare cable (copper would probably be best) simply join all of the stanchions, chain plates, engine, mast and both pulpits to one of the large keel bolts or a grounding shoe. It need not be fancy and you'll have to find a way to connect the stanchions below deck but you'll have a safer boat in the end. As I said my system is bare, heavy, single strand wire. I don't know wire measurement but mine is about 1/8" or a little less in diameter. Regards, Mike Glover Pitterpat
bare wire for bonding?
Just wondering: Why bare wire for bonding all the metal components? Wouldn't insulation help prevent arcing inside the boat, and reduce the likelihood of someone getting shocked by being to close or touching a bonding wire? Granted, the insulation may provide relatively little resistance vs. a lightning strike. Is there a disadvantage to using insulated wire?
Just wondering: Why bare wire for bonding all the metal components? Wouldn't insulation help prevent arcing inside the boat, and reduce the likelihood of someone getting shocked by being to close or touching a bonding wire? Granted, the insulation may provide relatively little resistance vs. a lightning strike. Is there a disadvantage to using insulated wire?
bare wire ground
JohnS I don't know why but the grounding system in my home and on my boat are both bare wire. It's true that in house wire romex the ground (usually green) is inside the romex sheath with a little paper around it but it is essentially unprotected by insualation. It's also true on my boat that the ground for the lighnting system is bare wire. Perhaps it conducts better or there may be a huge sudden heating from a lightning stroke and the bare wire may allow the heat energy to dissipate freely. Perhaps an electrician or electrical engineer would know the answer. Regards, Mike
JohnS I don't know why but the grounding system in my home and on my boat are both bare wire. It's true that in house wire romex the ground (usually green) is inside the romex sheath with a little paper around it but it is essentially unprotected by insualation. It's also true on my boat that the ground for the lighnting system is bare wire. Perhaps it conducts better or there may be a huge sudden heating from a lightning stroke and the bare wire may allow the heat energy to dissipate freely. Perhaps an electrician or electrical engineer would know the answer. Regards, Mike
bare wire
The ground wire should never have any electrical potential relative to anything in a house or a boat, therefore there is no need to insulate it unless corrosion is an issue. If there is electrical potential between a ground wire and anything else there is a problem somewhere else. All cabinets, chassis, appliances enclosures, etc are bonded to ground either by a mechanical connection, or the third lug on their plug. Otherwise if a short occurred internally, the cabinet could be at the same voltage as the supply, imagine leaning on your washing machine when it has 120 volts in the chassis. I knew of a guy who used to cut the ground lug off all of his extension cords. One day he replaced the plug on his metal cased Skil saw, wired it backwards, climed up on a metal roof, pulled the trigger and zapped himself, couldn't let go of the trigger, fell off the roof two stories with the saw in hand still running. All energized conductors should be insulated from grounding, either with insulation, or in an approved enclosure.
The ground wire should never have any electrical potential relative to anything in a house or a boat, therefore there is no need to insulate it unless corrosion is an issue. If there is electrical potential between a ground wire and anything else there is a problem somewhere else. All cabinets, chassis, appliances enclosures, etc are bonded to ground either by a mechanical connection, or the third lug on their plug. Otherwise if a short occurred internally, the cabinet could be at the same voltage as the supply, imagine leaning on your washing machine when it has 120 volts in the chassis. I knew of a guy who used to cut the ground lug off all of his extension cords. One day he replaced the plug on his metal cased Skil saw, wired it backwards, climed up on a metal roof, pulled the trigger and zapped himself, couldn't let go of the trigger, fell off the roof two stories with the saw in hand still running. All energized conductors should be insulated from grounding, either with insulation, or in an approved enclosure.
what a trip
Reudi, Yyou are right as rain, and you provide a good description, thanks indeed. Interesting narrative about the modified skil saw wiring. My dad was always bad to rip the safety grounds out of grounded power cables. JohnS, The wire you describe sounds like 6 gauge solid ground wire, used for earth driven ground on house wiring, telephone poles, and obviously on boats as well. It's really helpful to know some practical schemes for lightning grounding, so I'll be much better informed when inspecting/installing same in my own vessel. Thanks again, Anthony Drake.
Reudi, Yyou are right as rain, and you provide a good description, thanks indeed. Interesting narrative about the modified skil saw wiring. My dad was always bad to rip the safety grounds out of grounded power cables. JohnS, The wire you describe sounds like 6 gauge solid ground wire, used for earth driven ground on house wiring, telephone poles, and obviously on boats as well. It's really helpful to know some practical schemes for lightning grounding, so I'll be much better informed when inspecting/installing same in my own vessel. Thanks again, Anthony Drake.
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