# Distribution Block: One 4 ga in, Two 4 ga out - Fuse Necessary?



## BEbengali (Mar 25, 2008)

I posted in this forum because I know it has been discussed before, but I haven't seen anything for my specific case.

My install:
1 Alpine MRP-F300 Amp with two 25A fuses (150W x 2)
1 Viper D600.1 Amp with two 30A fuses (600W x 1)
1 4 gauge power wire from the battery with a 120A Mini-ANL fuse (KnuKonceptz amp kit)
2 4 gauge ground wires (one off each amp, grounded individually)
1 Distribution block to deliver power wire to both amps

Wire coming out of dist. block = 4 gauge
Wire length after dist. block = no more than 3 feet
I ran an amp set-up similar to the one above where I used an unfused distribution T block without any issues. According to bcae1.com, wire C below does not need a fuse since it is a 4 gauge wire just like the main 4 gauge power wire, so it is protected by the main fuse. ("_Wire "C" is supplied power from the dblock. Since it's also a 4g wire, it needs no fuse. The main wafer fuse will protect it and the vehicle in case it's shorted to ground_.") 










Is this one of those things where a fuse is not needed, but just there in case? Or will the wires after the distribution block be protected by the main fuse in the same way a fused dist. block would?

If I ran unfused, I would get this:
Stinger Gold 4 Gauge T Ground Distribution Block SPD811 - eBay (item 400180597052 end time Jan-11-11 18:46:10 PST)

If I went fused, I was looking at this:
TSUNAMI TSFDB2-MANL 2 POSITION DISTRIBUTION BLOCK - eBay (item 170546188097 end time Jan-25-11 20:42:32 PST)

Since both options are cheap, I thinking it might be worth the piece of mind to go with the fused dist. block, but I'm not certain how it works. 

How do the Mini-ANL fuses install into the distribution block? Will I need two fuses with the Tsunami fused block above since I have two output lines? If so, will two 120A fuses be okay since I am using 4 gauge output wires?

Any help would be greatly appreciated, whether it's on the necessity of fusing or how the mini-ANL fuses work in the dist. block 

Thanks,
Brian


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## stereo_luver (Oct 30, 2007)

Its best to use a fuse in case of a short. Never hurts to be safer than to be sorry later.

Chuck


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## Duncan345 (Apr 30, 2010)

You could probably get away with a non-fused distribution block in that scenario as long as you were careful with the wiring install. But as you said, the added piece of mind is certainly worth something. I would go with a fused block just in case.


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## Oliver (Jun 25, 2007)

I personally would not branch 2 wires that were supplied by 1 wire of the same size.

0 awg	330 amps	2731 watts	3414 watts
1 awg	262 amps	2168 watts	2710 watts
2 awg	208 amps	1720 watts	2151 watts
3 awg	165 amps 1365 watts	1707 watts

gauge..... amperage..........AB watts.........D watts
4 awg....	131 amps.......	1084 watts......	1355 watts

pick a larger wire to supply the power from the battery to the distribution block !

http://www.bcae1.com/

#16 wire

The supply line should be of a sufficient size to insure adequate flow to the subsequent branch lines [ a two gauge wire would be the smallest I'd go ].


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## skywolf75 (Nov 4, 2010)

Fuse it. It is to prevent any spark (that may cause fire) if it shorts.


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## RBeachTL (Jul 21, 2008)

From a safety standpoint you only need to fuse when reducing wire size. The 125 A. fuse will protect your downstream wires. Although, from a safety standpoint the additional fusing can't hurt.


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## KiNg MaRtY (Dec 3, 2010)

Just fuse it, not worth the risk of not fusing it.


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## RBeachTL (Jul 21, 2008)

Hey King,

What risk? If there is no decrease in the wire size, how will a downstream fuse have any effect at all?


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## SoundChaser (Apr 3, 2009)

If one of your wires shorts out, what’s the chance of the fuse by the battery not blowing? Slim to none. Personally i wouldn’t bother adding more fuses.


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