Fuse Size for 0 AWG and 4 AWG?

Hey,

I've got 0AWG running from battery to distribution block in my car.

0AWG is technically overkill for my application, but I may expand to further amps in the future and therefore I chose the biggest power wire so I don't have to run it twice.

My question is on the sizing of fuse along the wires!

As I read in this thread 4AWG would be fused to 150 for protection

0AWG runs to the block, 4 AWG runs out to the amp from the block

0AWG should be fused to ?
4AWG should be fused to 150A?

Oh , my amp is fused @ 70A

zero gauge wire's rated carrying capacity is 350 amps, so a fuse around that size will do, 4 gauge at 150 amps is correct. The fuse on the wire is to protect the wire, the 70 amp fuse on the amp protects the amp!

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COMMIT YOUR WAY TO JEHOVAH AND HE WILL ACT IN YOUR BEHALF. PSALMS 37:5

If you only have one amp on the power wire and that amp is fused at 70A you only need a 70A fuse in the 0awg wire.

A 70A fuse is the safest size fuse for the application, but anything between 70 and 350A will protect the WIRE.  The important thing to remember here is that fuses have delays in them, and the higher the fuse rating the longer it will take to blow, which could theoretically damage electronics in your car from the "crowbar" effect before the fuse actually blows.  Depending on the capacity of your battery it could take several seconds for a 350A fuse to blow when shorted directly to ground!

I guess what I'm trying to say is If you're only worried about only protecting the wire go with a 350A fuse, but if you want to protect the car, too, don't go any bigger then actually have to (70A).  You can always get a larger fuse down the road if needed.

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Kevin Pierson

As mentioned above, it it almost like a weak link about timing to blow. Personally I would just get an ANL fuse holder so that you don't have to switch them down the road. But for right now for your setup I would only put in a 100A ANL fuse. So the 4 ga is protected and your amp has a fuse rating closer to what is in the box.

Then when you go big you can easily swap whatever size of ANL fuse into there up to 300A. (It is all dependent on distance too, and you don't find many 300A setups in the first place.) Biggest I go on 4ga is 100A

I've never heard of 0 gauge called "hot" gauge but I have heard it called "aught" gauge.  It's much more common to refer to wire actually bigger then 0 gague as aught - such as 2 aught and 4 aught.  Wire larger then 4 aught is usually referred to in mills (like 500 mils)

https://en.wikipedia.org/wiki/American_wire_gauge - look under pronunctiation toward the bottom.

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Kevin Pierson

Opiniarian: Anything larger than 4ga, forget the fuses, rock a circuit breaker.

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This is what I do for FUN!

i personally would put a fuse that is matched to the amp....for example if your amp has 70A of fusing on it, put a 70A fuse. if you can't find it then a 80A would work.  as mentioned above a fuze doesn't blow right away. they can handle more current then they are rated for but only for avery short time befor they blow. so i like to keep the fuse rating close to the draw of the system.

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Tri County KustomZ
certified installer

"sorry 350 amp fuses don't exist unless you make a special order."

Parallel two 175 amp fuses(CB's)and there you go.
Aught starts with 0 to 0/4 and MCM starts after (500 MCM)

audiocableguy wrote:

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"sorry 350 amp fuses don't exist unless you make a special order."

Parallel two 175 amp fuses(CB's)and there you go.
Aught starts with 0 to 0/4 and MCM starts after (500 MCM)

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Yea.
Here's one up to 450A.

tjjr8120 wrote:

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0 gauge in the car audio world is known as hot gauge

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Thanks for clearing that up for me Kevin.  I had no idea where he came up with hot gauge.  I guess his Dyslexia was acting up.  New meaning to the term "Double Hot Buckshot"

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Let's Go Brandon Brown. Congratulations on your first Xfinity Series Win. LGBFJB

i am an idiot wrote:

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tjjr8120 wrote:

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0 gauge in the car audio world is known as hot gauge

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Thanks for clearing that up for me Kevin.  I had no idea where he came up with hot gauge.  I guess his Dyslexia was acting up.  New meaning to the term "Double Hot Buckshot"

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I shoot my double-hot-six rifle all the time at the range. :D

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Life is too short to build slow computers or weak audio!