Fusing Main wire with multiple amps

[zoltman1991]

I'm a little torn. I'm seeing two direct opposite answers.

Here is my set up:
-Fosgate T1500 (man. recs 200a)
-Focal AP 4340 (man. recs 40a)
-Focal AP 4340 (man. recs 40a)
-0awg running into trunk AGM, into fused distribution block)

For one, what fuse size do I run for my main power wire?
-I'm seeing fuse for wire v. fuse for load. Either way, 300a would be a good size for both approaches, correct?

What's also throwing me off is that online sources are suggesting a 125a-150a MAX for a 4awg wire. This is directly against Fosgate's recommendations. Fosgate recommends a 4awg power wire with a 200a fuse. Again, this is throwing me off.

My current plan is to run:
-300a fuse by Hood battery.
-300a fuse before trunk battery
-200a/40a/40a into the distribution blocks.

would love everyone's insight.

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[Doxquzme Premium Member]

I'm a little torn. I'm seeing two direct opposite answers.

Here is my set up:
-Fosgate T1500 (man. recs 200a)
-Focal AP 4340 (man. recs 40a)
-Focal AP 4340 (man. recs 40a)
-0awg running into trunk AGM, into fused distribution block)

For one, what fuse size do I run for my main power wire?
-I'm seeing fuse for wire v. fuse for load. Either way, 300a would be a good size for both approaches, correct?

What's also throwing me off is that online sources are suggesting a 125a-150a MAX for a 4awg wire. This is directly against Fosgate's recommendations. Fosgate recommends a 4awg power wire with a 200a fuse. Again, this is throwing me off.

My current plan is to run:
-300a fuse by Hood battery.
-300a fuse before trunk battery
-200a/40a/40a into the distribution blocks.

would love everyone's insight.

Powerline fuses are to prevent fires, that 300A should work fine - 18" or less from the battery (not shown). Personally, for the main power/ground leads. I like using quality breakers instead (drawing has fuses shown but I use the T-Tocas, breakers there). You can turn them on or off with a flick of the switch, no fuses needed.

Don't skimp here fors are expensive! THose others that are $15 to $25 are junk.

Good:

Amazon.com

Best:

Del City Marine Rated Auto Reset, Surface Mount - 3/8" Stud | Del City

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Then you fuse to the amps for their protection, individually and I do use fuses for these for the aesthetics. Each amp should use the Mfr suggested rated fuse. This is how I hook up my three amps. Keep in mind, the fuses can be inline individually or from a distro block same same either way. The dual runs allow for parallel grounding of the entire system guaranteeing you always have an adequate grounding path.

If, as I do, the +/- goes through the metal body (mine run under the car to the rear) I also breaker/fuse them near the 2nd battery as well.

 

[metalheadjoe 10+ year member]

Fuses should be sized according to wire ampacity. Fuses between battery and amps are meant to prevent fires. They do not protect amps. If your amp draws more current than it should, your amp has already failed.