Getting to grips with cathodic protection here.
If someone had a 12, 24 or 48VDC system, say solar PV and batteries, and the battery negative is earthed, this means the earth is the cathode, and the positive rail of the electrical system becomes the anode.
Is it right that in moist conditions only, that the copper of the +ive rail is now more likely to corrode than the -ive?
Is it correct that this copper +ive can be protected by attaching a zinc or magnesium block to the copper itself?
I've seen the effects of a corroded anode in old 12V solar systems, the black copper oxide is difficult to clean up.