looking at a commander with a 32 volts system on it what is your thoughts on this can this be change to a 12 volt system and 24 system and what needs to be done
You could change everything to 12 or 24 volts if you really wanted - but only if you are doing a complete re-wire of the boat, replacing a lot of equipment all at once (lighting, water pump, panels, etc) and plan on changing the starters and alternators (generators) on the engines and generator. Not worth it.
I chose to embrace the 32V that was there, but not expand on it. New 32V equipment is difficult to find, so I have created a new complete (panel, fusing, battery switches, etc) 12V bank (less expensive and more availability of equipment than 24V) . The panel has extra space, so as 32V equipment needs replacing, it will be replaced with 12V stuff. Eventually, most of the 32V equipment will be moved over to 12V, but the engines and generator will always be 12V.
The advantage of the higher voltage is the smaller wires can carry higher amp loads, I=V/R. Another reason someone found two starter relays for their diesel.
Hello Tim S.:
Steve has a very good plan as to a gradual changeover from 32V. However, Tim M. has very good advice as well, when one has a diesel installation such as yours. Contrary to Steve, I would keep the main engines and the generator as 24V. Cables would be smaller than a 12V system and the efficiency from a battery standpoint is superior. Diesel installations today are wired as such with CC starting to do this in 1974 on their V8 &V12 Diesel installations way ahead of the other boat builders.