Selecting fuse size for multiple amp system

[jvanbev1]

Hello!

 

I plan on having 3 amps running on one power wire from the battery. I think it's 0 gauge...potentially 4 gauge.

 

I am wondering how to calculate the fuse needed by the battery terminal.  I've read that I should add the amperages of the amps up, but that would mean I'd need around a 375a fuse, which is way to big for either size wire, and seems too big in general.  Perhaps I'm over adding the amperages of the amps?

 

Alpine: 2 x 40a: 85a fuse

DS18: 4 x 40a: 165a fuse

Orion: 4 x 30a: 125a fuse

 

85 + 165 + 125 = 375a fuse.

 

https://www.amazon.com/gp/product/B00DDZNC68

https://www.amazon.com/gp/product/B075FH1C85

https://www.amazon.com/gp/product/B00OYG0CD6

 

Please let me know if I'm doing these calculations correctly and if I will, in fact, need a 375a fuse!

 

Thanks,

James

[Kyblack76]

Those ratings, are at max pull, and at a lowest impeadance load. You wont come close to pulling 375, not at all.  Id be shocked if you pulled half. 

That said, why youd do 4gauge, blows my mind. Do 1/0 at least, and put a 300 amp fuse front and back, and get after it. Ill bet you a billion dollars, you wont blown it. 

 

 

Edit- what kind of electrical do you have? do you have a 300 amp alt, and some reserve???

 

[jvanbev1]

@Kyblack76

 

I have a 145 amp alternator.  I'm not sure I'll need a bigger one with what I'm going to be running, but let me know what you think...I imagine I have a bit too much amp for the speakers

 

CSC65 x 2 (rear) . 100 w RMS x2

R-S65C 6.5 alpine  x 2 (front) 100w RMS x2

tweeter x2 30w RMS

mid mid Infinity kappa perfect 300m. 3.5 x 2 (front) 100w RMS x 2

Audiopipe apvb-120b 750w RMS

 

Max RMS total: 1410

Amperage 103a = 1410 / 13.7

 

If I do need a larger alternator, I'm not sure how I'd accomplish that on a 2002 corolla.

 

Edit: For electric I'm doing big 4 and Battery: XS D3400

https://www.amazon.com/gp/product/B074T49ZHQ