car audio question

[QueBert]

My fuse for my amps blew, the one that's connected to my battery. I have some stupid Mini ANL holder and apparently no B&M stores sell them. What is the difference between a 150a Mini ANL fuse and a 150a regular ANL fuse? The idiot at the local mom and pop stereo shop is telling me that "Mini ANL = teh suxs!" but can't explain why beyond that. Also do I base the size I get off of how many watts my system runs, or the gauge wire I'm running from my battery to my trunk? I'm running 4 gauge wire, but my amps aren't pushing more than probably 800 watts. Again the stereo shop guy is saying I only need a 100a fuse, but I've had other people say if you run 4ga wire you should always use a 150a one.

 

[ecom]

The difference between ANL and mini-ANL is the physical size of the fuse. They are not interchangeable because their lengths differ by a factor of 2. ANL fuses are available up to 300A and I think mini-ANL up to 150A.

The only issue I've had with my mini-ANL fuse was that I didn't know the circuit I was putting it into would be energized on contact. It got hot enough that the legs were deformed slightly but the fuse still works. Not the fault of the fuse though.

Your amp should have one or more fuses on them. What is the total rating of those fuses? You can use this as a basis since your amplifier won't draw more than the total of those fuses meaning the wire will never handle more current than that. For example if the amp has two 35A fuses on it, you can use a 80A fuse and it will be fine. There's no reason to go bigger since there's no benefit and you may be near the limit of the wire depending on the length of the run anyway.

You don't mention whether you have 800W RMS or peak, but if it's 800W RMS, you may have exceeded the limit for that wire.

Another issue of concern is how long is your power wire? If you have a 15 ft length of wire, I recommend that you don't go higher than 125W since approximate limit for 4AWG at that length is 130A before you experience V drop >0.5V. At 20ft, I would go with 100A instead for the same reason.

 

[ecom]

So basically my thought on the issue is this:

Take the total of the fuses on the amp(s) that you have and then find the fuse with the closest rating above it. If it's say the total is 60A you can go with a 80 and that will be fine also.

The fuse is there to protect the wire in case something bad happens on that circuit. The larger the fuse, the longer it may take the fuse reach the necessary temperature to open the circuit if there's a fault. For example a fuse that is loaded to 200% can take up to 5 minutes to open.

 

[brblx]

you fuse for the wire, not the amp.

max fuse size for 4ga is indeed around 125a or so. 150 is a bit much, but it shouldn't hurt anything, as already evidenced by the fuse blowing without your car catching fire.

there's no way your setup should accidentally blow a 150a fuse. you have a wiring problem. pull your power wire and look for a chafed spot.

 

[QueBert]

thanks for the replies, I'm going to get a regular ANL fuse holder today and a 100a fuse. Tis holder is missing one of the caps, and finding the fuses for it's impossible it seems. I checked my power wire brblx and I don't see anything exposed, it's Monster cable and the plastic shielding around it is about 3x as thick as any other wire I've seen. I'm also running Loom for all the exposed portions. I think when I was installing the holder I might have tweaked the fuse. Not sure if that can cause a problem but it was sort of bent and I had to flatten it out.

 

[Viperoni]

Regular ANL fuses will have less resistance through the contacts than mini-ANL's.
If you're running 4g wire, you really don't need it IMO.