Wire Gauge and Fuse Question.

As of know I have a 200watt amp on a 10 gauge wire with a 30amp fuse. I will be running a second amp (same model) and be using a distribution block. What gauge wire should I run from the battery to the disp block and what size fuse. As well should I fuse both 10gauge wires coming from the block to the amps? Would 8 gauge work, if I don't need 4 then I would like to keep it a bit cheaper.

To find your main fuse at the battery you will want to add up the total rms wattage 200+200=400 then divide by 12.8 = 31.25. So at max draw both amps will draw a total of 30 amps so you can use your same main fuse. As far as the power goes you can use the 12volts power and ground chart to figure that out https://www.the12volt.com/info/recwirsz.asp but you could use an 8 gauge wire the whole way around. Now you do not need to fuse the amps in between the amp and the distro block unless you want to. But if you decide to do so I would use a fused distro block instead of adding inline fuses. Just remember that your ground cable must be the same size or larger than the power cable.

I got a distro block but then after thought about the fuse part. Now that I know I don't need to, I'm all set. I have like 20 feet in total of 10awg running my amp now so I'm getting a piece of 8awg to run to the trunk where the distro is and will then use the old 10awg to run grounds and what not. Thanks a lot.

Sounds like you’re on the right track. Good Luck with the install, and if you have any more you know where to go.

I just have a question about the fuse, the amps both have 20amp fuses, is a 30amp by the battery going to be enough? I also wondered where the 12.8 number came from, is it voltage? Right now I've just got the one amp running but it's all ready for the new one when I get it.

I used ohms law, you can use the 12 volts ohm calculator to figure it out (you will want to use the top calculator) https://www.the12volt.com/ohm/page2.asp . From the specs you gave me (200 watts each 400 total) 30 amps should be ok but if you wanted you could put a 40 amp under the hood. And yes that 12.8 is the voltage. Now I use 12.8 because that is the voltage with the car off and will produce the most current draw.

Gotcha, I figured 12v had more draw.