Originally Posted by SiouxsieCat
In the top image, it appears there is a line going up front with an in-line fuse coming out of the fuzeblock.
I'm not an electrician, but that is redundant and not really needed, right?
That is correct. The lower value fuse will fail first, the higher value fuse doesn't *do* anything. Setting up two fuses in series doesn't offer any more protection than a single fuse.
Using two fuses in parallel allows you to pull more current, much in the same way twinning a water line will give you more output at the end of the pipe. IMO, if you've got an accessory pulling 30A (two 15A fuses), and it isn't a clothes dryer or electric stove, you're doing something wrong.