Fuse size for distribution block

[CanadianDream 10+ year member]

Hey guys. I have a directed 1100d5 amplifier. On the amp it has 3 45A fuses. I have a main fuse at the battery. The question is I have a fused distribution block. How do I figure out the size of fuse required. There is nothing in the manual, and I assume the triple 45A fuses means I could get away with a 50 to 60A fuse in the distribution block.

Any thoughts?

Click to read more...

 

[dleccord 5,000+ posts]

3(45)=135. Just put a 135 fuse at the distro if possible. Now granted that it wont continuously draw 135, but why only 50-60?

 

[CanadianDream 10+ year member]

Actually it is 40A amps just took a look at it again. Yea, so 120 amps makes sense. They are AGU fuses so I may be limited at 60, or 80 amps as I am not sure they are made any higher (at least in the glass cylinder style)

Wasn't thinking the 3 fuses were for each channel (front, rear, sub) but were redundant. Long week. A 120 Amp fuse just seems really high.

 

[Big Dee 10+ year member]

AGU fuses can be found in 120 A sizes I believe. You fuse to the wire, so assuming you're using 4 gauge wire after the D-block I would get some 120 or 100amp fuses and call it a day.

 

[CanadianDream 10+ year member]

So the distribution block looks like this.

http://www.crutchfield.com/S-xDB6KK295h4/cgi-bin/ProdView.asp?search=distribution+block&i=211CBR44A

The problem is I will need to use some type of glass cylinder agu fuse, fusing after the distribution block won't fix the problem.

Thanks.

 

[helotaxi 5,000+ posts]

The AGU style fuse is not rated for current above 80A. Either go with that or get a different fuse block that takes MIDI fuses. Of course if you aren't blowing an 80A fuse then you really don't need to upgrade.

The fuses on your amp are internally paralleled. ATC fuses are only individually rated to 40A, to fuse for more current than that with that style of fuse you have to run multiple fuses in parallel. The current is divided between the fuses and the total rating is the same as the sum of the fuses.