OK sailnet community, first; this is a great site full of information. Well, my project, (of many) to gut and rewire my 1979 Starratt45. I have removed the salon floor and old fuel/water tanks. Another story. But now I have a clean pallet to start from. I intend to move the battery bank from the engine room to the salon floor. three things; more weight towards the center and lower in the boat. Plus easier to service. I narrowed it down to 8 6v trojan T105's or T125's or equivelant GC2 batteries, plus 2 each 12v batteries dedicated to windlass and starter, switched accordingly. The majority of threads around here favor the T105's. Also, in the EV (electric vehicle) circles. But I still have to research life cycles of this battery family. Such as; Crown, Trojan, Deka, Interstate, US Battery, Rolls-Surrette...I have a cross reference chart to work from. I'll take any inputs from battery experiences, such as; easy to source outside of USA, easy to maintain, longest life cycles and best Ah per dollar value. I have steered away from AGM, GelCel and big 8D wets for many reasons. Although, If there was a 30 year battery, I would consider it. Since we change out wets every 5 years, a battery 6 times the price with a 30 year life would justify the cost. You see, I am after easy low maintenance. That leads me to the topic of this thread. I have search and read many articles about grounding topics, here and in marine books. I have understood most of it have drawn up a plan for each system.
However, my question is a theory about DC grounding. Does our boat DC system have to be grounded thru to water (earth) or can the DC system be capacitve isolated as in an automobile? I had a plan to put a lovejoy coupler between the propshaft flange and tranny to isolate the engine. These flexible couplers do a few things; isolate current, vibrations and account for slight missalignments. I want to use the engine as my DC - ground. I think the AC ground would go thru to seawater since seawater is earth. I came up with this from reading threads about corrosion, stray voltages, shorts, and such. Also, could I use my 12,000# lead keel for any type of grounding (DC, AC, RF)? I have fabricated a non cunductive spacer for the mast and step to isolate the keel (encapsulated keel) from lightning strikes and will bond the foward and mid chainplates to the mast tying them to a solid copper plate sandwich thru the hull. I figured the rear stays will have RF isolators and be bonded to the SSB tuner and thru to a Dynaplate via copper foil. (Gordon West reading). Next, should the Zinc galvonic system bonded to the thruhulls be stand alone or bonded to the AC ground. I think isolating the Direct Current system , boats DC system would suffer less damage from surges, lightning, corrosion and stray draws.
Could some one could simplify the 5 grounding systems in the title. Is there a master One All code manual for marine wiring? Homes, autos, airplanes have codes. Seems that boats are flavor of the day techniques. ABYC has standards but others have written different and don't all agree with ABYC. so lets figure it out once and for all. Thank you