I need to figure out what fuses to use in my distro block and near the batt. I have a JL 250/1 and an ED Nine.2x. The power wire from the distro block to each amp is 4awg. The power wire from the batt to the distro block is 0awg (in case i need to change out the amps in the future). the wiring is knukonceptz. the 0awg is copper-coated aluminum. the 4 awg is straight copper i believe.
the JL is obviously rated at 250x1 rms. the nine.2x is rated at 200x2 but is likely closer to 235x2 at 14.4v.
so i have one ANL fuse near the batt, and two mini-ANL fuses in the distro block. how many amps should each fuse be? is the fuse size based off the wire size or the current the amp uses?
the fuse needs to be no bigger than the wire can supply. So up front you can go as high as 300A. And your 4 ga 125A. However, there's no reason at all to go that large since you know your amps will never draw anything close to that much current. In your case I would fuse at something near the peak current draw of your amps. For the 250/1 I'd probably go w/40A, for the ED 60A. 100A up front and you should be set.