Your RM2354 fridge IS a 3-way ....120V AC element, Propane & 12V DC element
The DC Power Supply to the terminal block in outside fridge compartment should be fed from the battery with a 30A in-line fuse close to battery . NOT from a Fuse in the DC Dist panel.
The DC from terminal block also feds DC to circuit board and the 3A fuse on circuit board is protection for the DC controls, propane etc
The DC element is powered directly from the terminal block in outside compartment with a 30A in-line fuse before the DC power goes to the DC Element Relay---hence the reason the DC Power should come directly from battery,
DC Dist Panel fuses are not set up for 30A fed.
Normal amp draw for your DC element---150W/12.5A
A 2-way fridge WOULD be powered from the DC Dist Panel via a 5a, 7.5A even 15A fuse....but not 3-ways.