Amp Wiring

A electrical connection can only flow as strong as its weakest point...  With all this high current large amp wire thats like 8-0 gauge, it doesnt make sence to me that the fuse is like a few mm thick...... how does that work??? whats the point of getting 4 gauge wire if your fuse is very thin?  please enlighten me

Well don't forget that the wiring used in cars is stranded and therefore is not as dense as the solid piece of metal that makes up a fuse.  I think that's why the fuses can pass that much current through them.

Although I agree with you--it seems hard to believe that it's even possible to cram all those strands of a 1/0 gauge power cable into a 1/8" piece of metal. 

Please tell me i think this is so strange...

its not about how much current can flow through it, its about the resistance, take the ohm meter, and put it on 1 ends of your power wire, you should probably get a LOW LOW rating like ..1-.5 ohms or something, then connect it to each ends of the wire again but let it flow through the fuse... if the ohms read higher then the fuse it causing some resistance that you dont want.. if not, then the fuse lets the current flow threw w/o any troubles...

I seen a PPI truck one time and they had no fuses in it at all, where they had distobution blocks that just cut off a bolt that was the same size as a fuse and put it in its place, if they were doing that then i would bet fuses cuase some unwanted resistance.

my two cents, have fun.

Eric

a fuse has to be small or else it will not blow when the maximum current draw is exceded. Yes it does create a resistance and heat  but only for about 1/2 an inch, it is a nessesary evil for safety. If you use small gauge wire for the entire run it would be the same resistance as the fuse every 1/2 inch. so it would add up very fast, then if you tried to pull any current though it you would most likely have a fire.

Power = Current^2 x Resistance , the thicker the wire the lower the resistance.

I dont know maybe im just illinformed but i have never heard that electricity goes on the outside of the conductor, since it is moving electrons that form the charge. Most house wiring is not multiple strand, most romex is 3 strands, hot neutral and ground. although i could very well be wrong.

Most house wiring is NOT stranded at all, it is a solid conductor;  This is part of the reason why wire nuts work well on house wiring but not in automotive wiring.

We seem to have gotten away from Okoboji's original question.  It's not just about resistance, because if you try to send 300A of current through a 14-gauge wire it will just not work, no matter how short the length of wire is.  Or am I wrong about that assumption?  Anyways that's really what his question comes down to because the actual amount of metal contained in a fuse is certainly not more than the amount of metal in an equivalent power cable.  Basically, why aren't fuses at least as large as the power cables themselves?