What size fuse for big 3

[Gh0st]

Power from battery to alternator, alternator is 120a, what size fuse would be good, this is just for the big 3 wiring not the amplifier, also I’m running 4 awg. Any help is appreciated.

Click to read more...

 

[audiobaun 5,000+ posts]

Its not necessary to run a fuse from Alternator to battery for the Big3.I would be using OFC wire for the Big3

 

[audiobaun 5,000+ posts]

Amplifier supply at the battery Fuse that with a weather sealed ANL Fuse block(Highly recommended).. to a Fused Distro Block,(Recommend Mini, or regular sized ANL fused block) and a solid Distro Ground Block

 

[Gh0st]

Its not necessary to run a fuse from Alternator to battery for the Big3.I would be using OFC wire for the Big3

I am using 100% ofc wire, but I’ve heard people say you should fuse that wire, and some say not to, but I guess just to prevent problems if you have a short?

 

[Gh0st]

Amplifier supply at the battery Fuse that with a weather sealed ANL Fuse block(Highly recommended).. to a Fused Distro Block,(Recommend Mini, or regular sized ANL fused block) and a solid Distro Ground Block

That’s all done, amplifier power is fused w anl waterproof holder, I don’t have a dist. Block, only running a single amplifier to subs.

 

[Deiimos]

Technically it should be fused by the battery, and you fuse wire based on its size. I’ll admit my alt to battery run isn’t fused, but I do highly recommend it for safety.

If the wire rubs / short, or you get into a collision and it gets pinched, it’s a fire hazard. Any wire that connects to the battery, which is a very high current source, is supposed to be fused close to the battery.

Here’s a good chart from a solid source. Wire / recommend fuse sizes from bcae1.

 

[audiobaun 5,000+ posts]

I am using 100% ofc wire, but I’ve heard people say you should fuse that wire, and some say not to, but I guess just to prevent problems if you have a short?

As Stated ..Recommended to do so..and a Safe practice. I havent had any issues with any of my 4 vehicles and vehicles before that for several years. Thats me. If you do choose to do so. I recommend using Copper ring terminals and an ANL Fuse with a weather proof Fuse holder that accept Ring terminals with bolts to keep connections secure

 

[shredder2]

As stated by others, fusing from the alt is unnecessary unless driven by the flywheel or rear axle... lol.
250A on the runs front to rear from front batt or delete to back bank and thats with 2/0.
Don't buy trouble and overthink it or overfuse it... its more places to fail if any connections are not perfect.
Reference any wire guage guide for your application and be sure of your grounds.

 

[Orionsundown]

I am using 100% ofc wire, but I’ve heard people say you should fuse that wire, and some say not to, but I guess just to prevent problems if you have a short?

Fuse anything going to the battery 150amp fuse I would do. if it shorts you saved your battery, and than you look for causes why it happen, if nothing happened, than your good. Altho big 3 with a 120amp alternator to me is pointless your electrical in the car alone should support that load. Placing a fuse on a 120amp alternator needs to be around what the alternator puts out, a 200-250 amp fuse is point less it'll never pop unless a major surge in power at that point it's to late the fuse never popped the whole purpose of fusing is to save your gear !!