this was a special request from the new owner. He wanted to charge his batteries with voltage up to 32V, but did not want to feed his appliances with 32V (while charging), so, this DC/DC converter was supplying all the appliances, except the big motors (winches, windlass, furlers and bow-thruster) with a maximum of 26 V.
In my opinion, this system is obsolete and potentially dangerous (because of the 32V charge settings).
You may take down this device and come back to the usual wiring, BUT, make sure first that your means of charge (alternator on main engine and battery chargers) don't go above 28.8V.
If you're not familiar with DC electricity, you should hire a skilled company for that.