Hello,
In the manual, it's mentioned to put a fuse on the neutral wire when connecting the ET112 (https://www.victronenergy.com/live/energy-meters:et112), but it doesn't state what type of fuse?
There's not much information to be found. A manual from Carlo Gavazzi makes it look like this is optional (https://gavazziautomation.com/images/PIM/DATASHEET/ENG/ET112_DS_ENG.PDF), but it's not clear at all.