Dumb question about fuse size.

[EO]

I will be installing one 55Wx4 and one 100x1 amp. I ordered a 4 gauge wiring kit because bigger can't hurt. It came with a 60A inline fuse.

If I ever had a short...would my battery deliver enough current to blow a 60A fuse? I just assumed "yes", but this question popped into my head today & I'd hate to find out later this wouldn't work.

 

[JTang]

Yeah, but your concern isn't really about the fuse size with the battery. It's the fuse size with the wire guage. The fuse should be smaller than the wire's power rating so that the fuse will pop before the wire gets so hot it melts or catches on fire. You could use larger fuses if you wanted, but I'm guessing that since it's prefused, its a glass fuse, and I think 60's the largest they go. If you want more, then you'll have to buy more expensive fuses and fuse holders.

 

[JTang]

No, if I were smart, I wouldn't have wasted all the money I did learning that I bought crap equipment and paying $80 to install drop in speakers!

"Allow myself to introduce - myself."- Austin Powers

 

[Brian's98XLT]

You can find the AGU glass fuses up to 80 amp. You want to make sure that the fuse at the battery is at least the same rating as the total of the fuses on the amp. If 1 is fuse at 60 and the other at 30 I would get a 100 amp GNL fuse (wafer style).
The main purpose of then fuse at the battery is to protect the car if the power cable shorts.

 

[EO]

JT, thanks. The kit came with a 60A fuse, so I'll assume it's properly matched for the 4AWG wire. I know this sounds rudimentary and obvious, but it never hurts to ask...

 

[EO]

Dang, these posts come in quick - 2 more while I was replying!

Now I'm confused again. The MTX Thunder4244 comes with two 25A fuses - I assume that's 50A total? I can't find a published fuse rating for the Thunderform w/100W amp, but let's say that's 30A. So now I have 80A total max current draw, which means I need a 80A+ fuse? Total wattage of amplifiers = 45x4 (sorry, not 55) + 100x1 = 280W.

An 80A+ fuse for a <300 watt system seems excessive. Am I thinking about this the right way? I appreciate the experience from those who've done this already.

 

[JTang]

Yeah, but you can most likely get away with less than the total fuse ratings, maybe even down to half of the total fuse size, since your amps will almost never play at full capacity for a long period of time. Like your sub amp will have a basic current draw at idle, and then spiky consumption from the bass notes.

 

[EO]

D'oh, those are MAX ratings! I think I even read that somewheres. That makes more sense now.

So what do people install when they compete? Bigger alternators & multiple fuses/power lines?

 

[DaninCO]

those things cant cost that much

 

[JTang]

Danin's right, the stuff's not THAT much, but for example, one 110 amp fuse cost me about 15 bucks. Now that sucks. In addition to the fuses for the fuse blocks that cost 8 bucks for a pair, and I had to buy two pair for the different sizes and so I have the extras laying around doing nothing. But the fuse holder for the main line that holds the 110 amp fuse was very expensive, like 25 buck, I think and my fuse holder was $75 to hold the high power fuses. Stupid, now that I think back on it, but oh well.

If you're competing, you're talking about a whole different arena (and tax bracket) since everything will end up being gold or platinum plated, etc. Since there are different categories, you could still compete in SQ among different amp/wattage classes, so you don't need a whole bunch of stuff.

If you're just doing your system and not caring to show if off, you don't have to worry about getting the nicest stuff, unless there's a specific piece that happens to really suit your needs. For example, silver is really more suitable for electronic transfer, but gold is used because it holds up against the elements better, esp. in the car, as well as it being more malleable for better contact between RCAs, though I wonder really how much.