HELP with fuses

Blasphemy; no one is supposed to agree with me. At least not about electronics and wiring.

 

I suppose the whole "hip" world of audio equipment isn't the same as being code wiring a house or wiring all electrical components in cars.

Yes, The in-line fuse is there to protect the wire, yes it should be as close to the battery as allowed, yes you can instal an in line fuse for whatever the max current is in the wire but why would you risk blowing something further in the circuit, where the fuses may require disassembly or may even blow the whole unit, rather than just replace a fuse that's in-line an an easy location to get to.

 

... If the amp draws too much current it will blow it's fuses which are normally located on the outside of the amp.
If the wire draws too much current it blows the fuse located at the battery.

You're over thinking this. There's nothing "hip" about the correct way of doing things. And you're not installing a fuse for the max current. You're installing one under that.

 

No where did I say that you should fuse to the max capacity of the wire. I did say that your fuse can be as large as the maximum safe ampacity of the wire. The other determining factor is the components that you are powering on that circuit. Your minimum fuse size should be the sum of the fuses being wired. I am defining a range of fuse sizes that would be applicable for a given circuit.

But in your example, you would need to fuse the power wire to the same size or smaller than the smallest fuse on the circuit. This doesn't make much sense if you have multiple devices wired into the circuit. You could be blowing that fuse pretty regularly if you did that with multiple devices running at the same time.

 

If your amp was less than 18" from the battery would you put a fuse between the amp and battery, probably not.

The 8ga wire is essentially just moving the battery closer to the amp, and the fuse (the one close to the battery) is protecting the wire.