Dear Maine Sail,
I have read many discussion regarding the need, use, and installation of galvanic isolators. I don't understand why one should NOT install the galvanic isolator at the junction between the DC ground and the AC green ground. Installing at the DC/AC junction seems like a "fail safe" installation. The green AC safety ground is never broken therefore it always remains a fail safe.
In this case, one could purchase a more affordable non fail-safe GI or use a decent 50A DYI galvanic isolator (which can be made for under $20). Any failure of the GI would only isolate the DC ground from the AC safety ground, which is probable the case for most sailboat under 40' anyway. More important, I would guess, is the use of GFCI protection on all AC circuits.
I have read many discussion regarding the need, use, and installation of galvanic isolators. I don't understand why one should NOT install the galvanic isolator at the junction between the DC ground and the AC green ground. Installing at the DC/AC junction seems like a "fail safe" installation. The green AC safety ground is never broken therefore it always remains a fail safe.
In this case, one could purchase a more affordable non fail-safe GI or use a decent 50A DYI galvanic isolator (which can be made for under $20). Any failure of the GI would only isolate the DC ground from the AC safety ground, which is probable the case for most sailboat under 40' anyway. More important, I would guess, is the use of GFCI protection on all AC circuits.