Fuse Question

[RebelDogg 10+ year member]

I'm putting a zx750 and a CVX 12 in my car Saturday.

Right now I have a 4ga wire with a 100a fuse running from the battery split into two 8ga's for my zx400.1 and my zx250.2 The ZX250 running two 75wRMS componants.

When I replace my current sub and amp with the CVX, I will be upgrading to a 1/0 from the battery split into a 4ga to the 750 and an 8ga into the 250, but the shop was out of a few things I needed to buy today (fuse holder, distro block, fuses...) and I had to order. I plan on just running it all on the wires I have now for a few days until my stuff comes in.

My question is will the 100a fuse on the 4ga wire at the battery be okay? I don't know how to figure amps, but I heard the zx750.1 pulls about 85a. I'm not sure about the 250, but I would assume it pulls about a third of that (say 30a) which would be a total of 105a. Will the fuse blow right off?

If it makes a difference, the 4ga is 17ft to the block. 8ga wires are about 3ft or so with a 30a fuse and a 50a fuse.

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[Rashaddd 5,000+ posts]

Just keep your gains down a little untilyou get better wiring

 

[hemi=22s 10+ year member]

bad idea just wait for the good stuff

and then put 300 up front

and 2 150s in the back

 

[RebelDogg 10+ year member]

Just keep your gains down a little untilyou get better wiring

Thanks. I was thinking that, but I wasn't sure if it would make enough difference. Going to be a rough few days... I'm used to cranking it to and from work. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[Rashaddd 5,000+ posts]

Thanks. I was thinking that, but I wasn't sure if it would make enough difference. Going to be a rough few days... I'm used to cranking it to and from work. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

Your amps will only draw what they put out (plus some that goes to heat)

 

[RebelDogg 10+ year member]

bad idea just wait for the good stuff
and then put 300 up front

and 2 150s in the back

300 up front? The guy in the shop ordered me a 200a wafer fuse.

2 150's in back? I've got a 30a fuse on my distrobution block for my zx250.

Know any good reading material online where I can brush up on this stuff? //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

 

[knukonceptz 10+ year member]

.
Know any good reading material online where I can brush up on this stuff? //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

http://www.caraudio.com/forum/showpost.php?p=4771612&postcount=17

Use the amp's fuse rating as a guide for the fuses in the block, if the Kicker has a 30A on board, use a 30A on that leg of the dist block. For the main fuse near the battery, fuse it either for the max capacity of the wire you have installed or for the total of the fuses in the block added together(what I recommend). The latter is more safety minded and there is no loss in performance for proper fuse size.

 

[RebelDogg 10+ year member]

^ I was actually just now reading that thread!

I was wondering though, with my zx250.2; I figure it pulls 30a but since I'm only putting out 85w x 2 channels (actually, the speaker are 75w so the gain is turned down a bit. So 75w) would the amperage be less? Like maybe 15a? That would mean a total draw of 85 + 15 which is 100a. And if I turn the gain on the 750w amp down some, it should come in under 100a.

And would it hurt anything to just temporarily put say a 110a or 120a fuse on the 4ga?

This is all just until Wednesday when my stuff gets here.

 

[knukonceptz 10+ year member]

According to Kicker's Site the ZX250.2 uses a 40A fuse and the ZX750 uses an 80A so a 120A under the hood would be fine. You probably wont draw more then 100A because the ZX250 will never draw full capacity since its not playing bass notes and that is what causes the bigger consumption of current.

 

[RebelDogg 10+ year member]

According to Kicker's Site the ZX250.2 uses a 40A fuse and the ZX750 uses an 80A so a 120A under the hood would be fine. You probably wont draw more then 100A because the ZX250 will never draw full capacity since its not playing bass notes and that is what causes the bigger consumption of current.

Okay. Thanks.

One thing I'm still not sure on, though. I read that a 4ga wire can be fused up to 125a. So if I put a 120a fuse on there, I'm not risking melting the wire or... whatever happens when the wire takes too many amps.

I think I kind of get it, but I'm just being overly cautious. I really don't want to screw up anything in my car or my stereo. //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

 

[knukonceptz 10+ year member]

No, no meltdown will occur, you just have an excess voltage loss at the rear, heat would not become an issue unless you are constantly drawing 120A. Such instances are only from test tone/sweeps used for DB drag or tuning a car. Music rarely draws constant because the low notes are not constant like a test tone.