The RV manufacturer’s code calls for a fuse within 18″ of the batteries. As to the disconnect, the manufacturers normally have one. I don’t recall if the code requires it. I do not have one on the inverter I installed in our fifth wheel and glancing at Xantrex wiring diagrams I do not see one.
Steve and Andra
2012 F350 6.2 gasser SRW LB
Fab Fours front and rear in case we run into a rhino
2019 Northstar Laredo SC