power wire and distribution block

I'm doing a big audio upgrade in my 2006 Crownline 236LS (Boat) and I have a couple of questions that I can't seem to find the answers for.

I'm installing a Profile AP1000M amp to power an Alpine SWR 1042D 10" DVC Sub that I'm running at 2ohms.  I'm also installing an Infinity Reference 475A 4 channel amp to power 4 new Infinity 602M speakers.

After some research on this forum I decided on using 1/0 power and ground to a 1/0 to 4 guage distro block.  I'm running the ground back to the battery because the grounding block on the boat can't handle the load.  So basically I'll have 2 runs of 1/0 guage (power and ground) to 2 distro blocks.  Then 4 runs of 4 guage (power and ground for 2 amps).

1. I've got about 15 feet to go from the batts to the amps.  Do I want to run 10 feet of 1/0 guage and then distro followed by 5 feet of the 4 guage.  Or shorter 1/0 guage and longer 4 guage?  Or does it matter?

2.  One of the 4 awg amp kits I purchased seems to only be about 4.8 mm compared to the kicker kit I purchased which is easily 6mm or larger.   Is it imperative that I get some more "true" 4 awg wire or should I just use the "cheaper" kit for the amp that's pulling less power?

I appreciate any comments or feedback.  Taking friday off to install all my goodies!

I believe that you have everything covered. Run the power and ground with 1/0 guage all the way till you get close to the amps, then get a disrtobution block (make sure you get the right size fuses for each amp) and seperate each to 4 guage. The only thing I would suggest is to get to within at least 3 feet before using the distrobution block. The thing to remember is the closer the better.

1. It doesn't matter.  However the install works out best for this situation.  Your wiring is plenty large for the application.

2. Use the wire you have.  It will be easily large enough for the task.

stzcole wrote:

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get a disrtobution block (make sure you get the right size fuses for each amp)

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The fuses in a fused distro are for the outgoing wires (in this case, 4 gauge), not for the amplifiers.  The amps have fuses.

One more question.

I'm fusing the 1/0 guage power wire with a 300 amp ANL fuse.  I've read on some other posts that a fused distro is not needed.  And from stevdart's comment I'm reading that as....

The fuse on the main 1/0 power line near the battery should be sufficient and no more fuses are needed?

Other than those in the amps themselves of course.

I will definately take some pictures.  I had the neighbor come down last night with his benzomatic and solder on my terminals to the 1/0 guage power and ground wires.  Took some pics of those.  I'll be sure to take pictures along the way and I'll post a good after action report when I'm finished.

Thanks for the suggestions and the information.

They're needed, so you should use them.  Although you could cut some corners and install the fuse value rating for 4 gauge in the main wire, you would be allowing the possibility for catastrophic failure later down the road. 

Scenario:  two years from now, you or someone decides to add another amplifier into the circuit.  The initial installation was far in the past, so some of the details are cloudy.  You see that 0 gauge wire is provided, so the device is installed.  The fuse value on the 0 ga. wire is looked at and considered too small for the application, so it is upped in value to 300 amps.  The two existing 4 gauge wires feeding out to the two year old amps are buried in the installation and overlooked (is it unfathomable to overlook this part of the installation that has never failed, as they have nothing to do with the newly added device?)  These wires now are not protected from getting hot enough to start a fire.

In an automobile, chances of catastrophic failure would be greater than on your boat because the entire chassis is ground.  It is easier, in that case, to envision how suddenly the battery reserves could get dumped through the circuit all at once.  But you should provide the same basic safety to your boat as much as you would to your car.  It is the standard for circuit protection to fuse to wire value.

The long and short of it is, you may not be standing at the ready with a fire extinguisher if a sudden catastrophe were to happen to your boat.  Don't cut corners.  Protect each wire at its rating and you will have set up the wiring correctly.  "2-6-8" the job and you will bear the burden of remembering what shortcuts you took from now on.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

sergeantnic wrote:

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That's what has me confused. Everything I've read here indicates fuse the wire to protect the wire. So I'm fusing my 1/0 gauge at 300 Amps near the battery.

Then I read to fuse the 4 gauge after the distro blocks. So I guess I'm just confused what I should do.

Luckily, I ordered some extra stuff and I have 2 extra fuse holders so it's not a big problem but I don't want to install them if they aren't needed.

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The purpose of a fuse is to protect the wire and the vehicle.  If you pull more current through a wire then it is rated for then the wire will heat up and possibly catch on fire.

The "problem" you have here is you have two different sizes of wire.  If you fuse your 1/0 at 300A (which seems WAY too high for this install) and you don't fuse your 4ga wire then you have the possibility of running 300A through a wire that is only rated to handle ~150A.  This can cause the 4ga to heat up and catch on fire (although this is very unlikely in your install because the 4ga wire in your install is so short).

So, you can do two differnet things - fuse the entire system at the level of the 4ga wire (150A or so) or fuse both legs (1/0 and 4ga) seperately.  If you have the extra fuse holders and you don't mind spending the money I would highly recomend the fuse holders in the back.  If you're trying to save money you can technically be safe and not use them IF your front fuse is 150A or smaller. 

It would be really interesting to see what kind of loads both amps are going to draw from the battery under full load as that is the most important information to have when properly sizing the system fuses.