Question about amp fuse(s)?

SportsFan

I have a question about fuses, and the size fuse to use (if possible) with an amp wiring kit.

I'll be installing an Alpine MRP-F240 amp within the next week or so (the amp's arrived, now waiting for RCAs and amp wiring kit). The RCAs are StreetWires Zero Noise 3 (ZN335), and the amp wiring kit is Stinger HPM Series 8 gauge (SWKH8).

This Stinger HPM Series 8 gauge amp wiring kit comes with a 60-Amp AGU fuse and holder....while the Alpine amp itself comes with a 25 amp fuse. I've been told that I should "MATCH" the fuse rating for the amp wire to the fuse rating for the amp. I've also been told that it really doesn't matter all that much

This amp wiring kit includes a 60 amp AGU fuse holder. I've seen other kits that have a 60 amp MAXI fuse holder. Seems like I've heard that the size of the fuse can be switched with a MAXI fuse holder, but I'm not so sure about the AGU fuse holders.

Sooooo......with the AGU fuse holder, will I be able to use a different size fuse, or is in mandatory to and will only use a 60 amp fuse

MacLeod

The 60 will be fine.

The only purpose for the fuse in the power wire is to protect should your power wire running thru the firewall have its insullation rub off and arc out against the firewall. If the fuse wasnt there, it could melt the insulation around the power wire and catch the inside of your car on fire. With the fuse inside the engine compartment, if your power wire arcs out, the fuse will blow and no current will pass into your car.

That being said, the only time you need to match fuses with amps is to make sure youre running a big enough fuse and in this case you are so the 60 amp fuse will work just fine. Just make sure its within 18" of the battery.

neomagus00

and by the way, ALL the fuse types come in multiple values and can be changed out... for your reference...

SportsFan

Thanks, Mac...

And thanks for that follow-up, Neo.

I was curious about:

a)IF they could be, and
b)IF they should be

I guess the answers are:

a) yes, and
b) no

But what are the main differences between an AGU and a MAXI fuse? And is one considered to be a better quality product than the other?

MacLeod

No. Maxi fuses can go up to higher ratings and thats about it. AGU fuses only go up to 80 amps where Maxi and ANL fuses go way up! I use a 80 amp AGU.

SportsFan

So the guy saying that the amp wiring kit's fuse should be matched to the amp fuse rating is full of it? I have spoken with so many different company reps and shop installers the past few days that I can't exactly remember who said what! I guess he must be one of these guys that either doesn't have his facts straight, or is ultra, ultra cautious (which isn't necessarily a bad thing, I suppose). But this is all new to me, so all the info that you guys can provide me with is greatly appreciated....

MacLeod

Well say you were running 2 amplifiers each with a 40 amp fuse. In this case youd want to match them which would be 80 amps. So basically he's right but all you have to do is make sure youre letting at least as much amperage thru as the amplifiers max rating.

Actually you could get away with a 20 amp fuse as an amplifier will probably never get anywhere near its max fuse rating.

SportsFan

So what would you recommend with this Alpine amp/set-up then, Mac? Keeping the 60 amp fuse....or trying to match it with a 25 amp fuse (or going with something in between like a 30, 40, 50 amp fuse, etc.)?

EDIT: I ran across this via Basic Car Audio Electronics web-site. It's a little chart for matching up the recommended maximum size fuse compared to the wire gauge size. Does this look fairly accurate?

neomagus00

for power cable, yes, and that's because the cable itself will begin to act like the fuse... e.g. if you put a 200 amp fuse on a 10 gauge cable, the cable could melt before the fuse!

and keeping your 60-amp fuse should be just fine, as long as you're using 4-gauge cable - which you should be...

SportsFan

neomagus00 wrote:

for power cable, yes, and that's because the cable itself will begin to act like the fuse... e.g. if you put a 200 amp fuse on a 10 gauge cable, the cable could melt before the fuse!

and keeping your 60-amp fuse should be just fine, as long as you're using 4-gauge cable - which you should be...

Thanks, but 'm using 8 gauge, neo.

This Alpine amp (MRP-F24) comes with a 25 amp fuse. It's a 360 watts max amp (40 RMS X 4 @ 4 ohms - NO SUB for my system, just Polk db650s and db690s!). Crutchfield (and some others) "recommend" 10 gauge amp wire for this amp, BUT....a few local shops (and even the StreetWires rep that I spoke with) recommended 8 gauge. So that is what I am going with - an 8 gauge amp wiring kit.....

MacLeod

Nothing wrong with using 8 guage if thats all you need. An 80 watt amp doesnt require wire as thick as a fire hose.

Keep the 8 guage and the 60 amp fuse you have and youll be fine. Now if you upgrade to some much bigger amps youll need to upgrade both wire and fuse.

neomagus00

okay, mac does have a good point...