Fuse Size?

hahah this one became funny.... but i have a ? for ya DYON

this is the first honestly that i have heard find a fuse according to the wire gauge..."interesting to me"

what ever happend to take the RMS divide by alternator output at idle ?

thanks man just wanted to ask ;) its been along time since i have seen yalls names ;) good to see yall agian

ok ,perfectly understood as well. but back when I worked at a shop that basically did 90% competition vehicles we would often use zero gauge when a 2ga or even 4ga would have sufficed. This never caused any harm, it looked great (well massive wire always does) and the judges appreciated it.

But if the systems demands were lets say for example, 125amp ,I would see no reason to install a 350a fuse..even though according to some here the wire "calls" for it.

In anyone elses opinion, was this improper or unsafe in any way? Keep in mind I am aware that a wire this large was "unnessesary" perhaps..but aside from the other listed  benifits of this "overkill"..it added nicely to our profit margin using the larger wire, distribution blocks and terminals.

master5, like I said before, the fuse is to protect the wire and one should size a fuse with the capabilities of the wire in mind.  If the wire is capable of carrying 350 amps, then the purpose of the fuse is to prevent MORE THAN 350 amps from being carried by the wire.  This does not mean you NEED a 350 amp fuse, just that you must not allow more than that.  Will your 125 amp fuse do this job?  Sure.  It's called being logical and understanding electrical safety requirements.

Thanks for the response, understood   

I'll chime in with a question related to a DIY build up 'cause i am at this stage, and you all seem to know the right answer.  I am installing a PDX 1.1000 amp right now and the wiring will probably be 4 ga at the amp.  however, I intend to add another PDX 2.150 or 4.150 later (3 months or less) and don't want to re do the wiring later.  i would like to understand what my 'best' method to power the sub amp now and future amp(s) later will be for wiring.  I am going to assume that the best should be to run 2 ga from the battery now (fused for wire size) to a 2 -4 output distribution block that can run 4 ga out to the amp(s).  Then I can run additional wiring from the dist block later as I require it.  Grounding will be the same ( I assume).  Is there anything technically wrong with this?  I am trying to avoid running wire twice and damaging my interior components by removing and replacing them over and over.  Also, buying wire twice (cost is always a factor :)  ) .

thanks.

Yep same here.  Basically I "pre-plan" for upgrades by installing a 4ga. or larger and using a distribution block. This way in the future when I add more power..or additonal amps etc. the main wire is already ran saving time and effort.

I will generally use a main fuse based on the power consumption of the device(s) connected to it..although I totally understand the premise of wire size being the determining factor. Once I perform the upgrades I will use the appropriate fuse(s) but I will never use a fuse with a rating that exceeds what the wire gauge can handle...or a wire gauge not up to task..I hope I did not give that impression.

hey all.

the wiring kit i recently purchased (absolute AB-404, 4 gage amp instalation kit) has a 60A fuse for the main power line.

now..the amplifier i have is 1600watt RMS (5000 watt MAX, although not relevant) which is using the 4 gage wire for power (duh)

should i get a 150A fuse to replace the 60A????

cheers

I would say that is a definate yes.

However for an amp with that kind of power a 2ga. minimum may be called for depending on the final ohms load. But regardless I couldn't imagine a 60a fuse lasting the first heavy bass note with that amp.

Good Luck.