Devices max draw should be up to 75% of fuse. This is because a fuse can still blow after time (due to heat factors) even if lower than rated fuse. Eg 95% load may blow in 30-60 mins depending on ambient temp. 100% in a minute or so.
You want your fuse rated lower than the wire rating, so if there is a fault, the fuse blows before the wire melts.