Off Grid Home Forums Technical Discussion Will my house burn down if… Re: Will my house burn down if…


If promoting a concept is selling something then I guess I am guilty. I have been installing inverter systems since 1995 and have learened a few things along the way. Boats are by their nature self contained and thus off-grid. Construction codes are for the most part as stringent as building codes on land. For the rest they are tougher.

what the OP was apparently asking about was if he was likely to burn something down by constructing a ring main. What he never said was what size wire he was using,nor how much load current he was expecting. Land wiring simply looks at load current and specify the wire gauge accordingly. Boat wiring code looks at how much load current is involved as well. this usually means calling up a ;arger wire than what the land code calls for. Quite often when dealing with low voltage like 12V we end up having to upsize in order to reduce the voltage drop to amounts specified by the marine code. For example for critical motor and control circuits we are not allowed more than 3% drop but lighting is allowed 10% voltage drop.

When dealing with 12V a 10% drop is 1.2V

For a 120V AC 1.2V is only a 1% drop.

I never said ventilation was not provided for the battery bank on a boat. What I did say; on a boat the battery is still stored on board where people also reside. You never see a boat towing a raft for a battery building.

The marine construction code stipulates how a battery compartment must be built

in a safe manner.

The cost of installing large enough wire to be safe is much greater in 12V systems than in 120V systems. Sine wave inverters are not noisy. MSW inverters are. This is something ham operators have learned from way back.