Amplifier wireing

deathjunior

Alright so I'm not quite sure what to do here i know what gauges ill be using and how to run it but I'm not sure on the fuses. I'm running 3 amplifiers, 1 MTX JH1200 and two Polk PA330's. I plan to use the stinger 1/0 gauge kit its the SPK5201R, from their ill use two distribution blocks into 3 4 gauge outputs. Then ill run 4 gauge to the jh1200 and 6 gauge to the two pa330's. What i need to know is do i need extra fuses, or is the 250amp fuse on the main 1/0 gauge line enough? Keep in mind there is no internal fuse on the jh1200 however the pa330's have their own fuses.

exalted512

I recommend fusing every amp individually. Even if it has onboard fuses.
-Cody

deathjunior

Well im going to have the fuse on the main line anyway, so whats going to be the point for the rest of the fuses accept further resistance, any surges would be protected by the main fuse wouldnt they?

exalted512

deathjunior wrote: »

Well im going to have the fuse on the main line anyway, so whats going to be the point for the rest of the fuses accept further resistance, any surges would be protected by the main fuse wouldnt they?

The point is if you have a 250 A fuse in the front, whats protecting your amp from shorting out and getting 250A of current and starting a fire?
-Cody

deathjunior

and if my distribution block was fused?

exalted512

then that would be fusing every amp, which would be good.
-Cody

deathjunior

So if each amp is internally fused than that protects the amp, and if the the main line has the 250 amp fuse than that will protect the battery, however if i swap the 250 with a 125 amp fuse to lower the amount of power that will blow it wouldn't that be safer, in that case ide just have to run an external fuse on the MTX's separate line since the other two have internal fuses as their protection.

exalted512

You can do that, but I still recommend fusing amps before the power goes into the amp...so even if the amp is already internally fused. KnuKonceptz has a 3-output fused distribution block for looks $20. Doesn't seem worth it to me to skimp out on $20.

-Cody

Jstas

deathjunior wrote: »

So if each amp is internally fused than that protects the amp, and if the the main line has the 250 amp fuse than that will protect the battery, however if i swap the 250 with a 125 amp fuse to lower the amount of power that will blow it wouldn't that be safer, in that case ide just have to run an external fuse on the MTX's separate line since the other two have internal fuses as their protection.

Internal fuse do not protect the amp from shorts that send surges down the line. They protect the amp if something internal goes bad and start to draw more than the circuits are rated aty. The fuse blows and cuts power some something bad like your car burning down doesn't happen.

The reason you fuse every amp in the system is simple. Like exalted said, if you have a 150 amp fuse to cover 3 amps of a 50 amp draw, each then you need to fuse individually. This is because the 150 amp fuse will not protect against, say, a 90 amp surge which is a big enough surge to burn up your amp with a 50 amp draw.

So, your main fuse is a 150 amp fuse or breaker and then you get a fused distro block with 3 50 amp fuses. This protects you from overdrawing your circuit or getting massive surges from your charging system (like when an alternator or voltage regulator goes bad). It also protects you from that surge that is bigger than what you amp can handle but smaller than what your main power feed is fused at.

Do you HAVE to do this? No, you don't HAVE to do anything. Is it recommended? HIGHLY recommended. The fuse protects your expensive amplifiers as well as prevents an over-draw situation from damaging your battery and charging system as well as other, much more expensive electronics like PCMs and ABS modules and such. It's an added cost now but an extra $30-$60 in protection and insurance is worth it because it's protecting 100 times that other electronics. Dude, seriously, splurge a bit. It's not just about protecting equipment, it's about safety too. Installation is everything.

Also, a fused distro block makes it easier to cut power. All you have to do is pull the fuse on the branch with the amp that you want to fix, replace or whatever. Then you don't have to reprogram your presets!

Jstas

Oh and when choosing fuses, you have to have a main fuse that covers all of your maximum draws. So if you have a 30 amp draw on a front stage amp, a 30 amp draw on a mid-woofer stage amp and a 60 amp draw on a subwoofer stage then you need a mainline fuse of 180 amps. They don't necessarily make them that specific so you would need something like 175. At the minimum 150.

That's because you have to account for the possibility that all 3 amps will be pulling max draw. It would really suck to be at a competition (or trying to impressed girls) when you're crankin' away on your tunes going for the high meter mark and your fuse pops.

So if you fuse your main line at a level that doesn't even allow the amps to run at a nominal level (maybe 40% of max draw) then you're not doing yourself any favors. Besides, if the actual peak draw is considerably more, you run a risk of a catastrophic fuse failure where the heat from the draw and the subsequent failure melts stuff and fuses the connection where the fuse is blown but the power is still connected through shorted out, a melted, failed casing. Or you could set stuff on fire and that's not a fun day either.

exalted512

Jstas wrote: »

Or you could set stuff on fire and that's not a fun day either.

Actually, I love setting stuff on fire. But more along the lines of ant hills and less along the lines of vehicles.
-Cody

Jstas

exalted512 wrote: »

Actually, I love setting stuff on fire. But more along the lines of ant hills and less along the lines of vehicles.
-Cody

I thought you would have harped on the point that I can't add.

I have 30, 30 and 60 which is 120. I meant to have 30 60 and 90 which would be 180. I never went back to change it.

I also can't seem to type today. I missed entire words in the first post.

exalted512

I guess I thought you were capable of simple addition
-Cody

Jstas

exalted512 wrote: »

I guess I thought you were capable of simple addition
-Cody

I am. Calculators rule! I'm just no good at typing apparently. Or proofreading and fixing my mistakes.

deathjunior

Alright so what should i use as the main fuse amp, cause the JH1200 amp asks for a 125a fuse if its hitting a peak output at 1 ohm, and ill be running it at the 1 ohm, but i dont know what the PA330's draw i think the 250 amp fuse will be okay on the main line, what do the PA330's run a 25 amp fuse each? Ill be running them at 2 ohms. My amps were just ordered so i havent seen em yet and ide like to have it all at once. Also what should i use for the individual fuses cause i havent found a distribution block with fuses like that anywhere.