plexi glass boxes

[evil0ne]

I didn't build it and it's not in a boat but:

[Domsz06]

yeah, you should be fine.

[Razzman]

My install is real easy. I'm not grounding to the motor and no water comes into play unless you throw it under the bow behind the seat where the batts are! If water actually gets to the amps then i'm sinking anyway so what the heck The only thing wires are passing through is the wood bulkhead that runs from the dash to the bow seperating the bow into two compartments. Where they'll run though the existing vent hose opening in the wood and be encased in that rubbery pipe insulation stuff. Everywhere else they'll be covered in that black accordian wire loom stuff.

[Domsz06]

i would fuse anything that might run through a tight opening where metal may be contacted, since the metal may have a way to ground. Or if your running the wires through something that could be wet and in water that could track back to ground, like the ingine block or something.

[Razzman]

I wouldn't. You don't have to worry about grounding the power line, and each amp will be protected by an integrated fuse.

Fusing is important in an auto because the entire metal chassis is ground. If a cable chafes or gets cut, you will have unregulated power dump to that short, maybe even starting a fire. In a boat, there is no chassis ground, or a firewall for a cable to chafe through. Fusing the wire isn't a necessity. Sure it offers some level of protection, say if a cable came undone, and touched ground; but that is a very unlikely scenarion, and one that can easily identified/stopped. You have component wires in your boat wired the same way right now.

Of course this is my logic, but I haven't seen any reason to do it otherwise. I don't think Lee's shop fuses any ballast pumps or other components they install.

So is there any scenario where fusing in a boat would be critical? If not then I'm dumping the blasted fused dist block and just running straight to the amps. One has two 30 amp fuses, the other a single 30 amp.

Also, i plan on adding a couple bus terminals for power and ground distribution for switches, gauges, etc. Any rules of thumb for that scenario?

[spharis]

You guys also have to remember the stuff I suggest is based on my experience/preferences....it is by no means a bible of sorts. i do find alot of things alot of installers to silly though.....polyfil in all boxes is one of them.....

[Domsz06]

Spharis,

thanks for the info!

Razz,

HA HA HA

[Razzman]

And here i've got two of the darn things inline. Ya know maybe we should start a another folder in this category for information. I know if somebody would have asked this question sooner and we had a stereo / systems FAQ respository I woudn't have spent money on a fused dist block Or the damned polyfill that's shoved into my sub enclosure, which is shoved into the bow, which requires me to play houdini to get to it after i pull the steering wheel to get past the dash!

[spharis]

I wouldn't. You don't have to worry about grounding the power line, and each amp will be protected by an integrated fuse.

Fusing is important in an auto because the entire metal chassis is ground. If a cable chafes or gets cut, you will have unregulated power dump to that short, maybe even starting a fire. In a boat, there is no chassis ground, or a firewall for a cable to chafe through. Fusing the wire isn't a necessity. Sure it offers some level of protection, say if a cable came undone, and touched ground; but that is a very unlikely scenarion, and one that can easily identified/stopped. You have component wires in your boat wired the same way right now.

Of course this is my logic, but I haven't seen any reason to do it otherwise. I don't think Lee's shop fuses any ballast pumps or other components they install.

[Domsz06]

so your saying you wouldn't use a fuse at all, not even one? Just wondering.

[spharis]

I wouldn't do a fuse, but if I did, I would add the sum, or use the rating for the length of wire/size.

[Domsz06]

so what size fuse would you recommend then for the 6 amps I'm running? just add up what each one is recommended individually and use that one big one?

[Domsz06]

thanks!! You rock!! Let me know those links and I'll check them out. no fuses saves me a ton of $$ as well as headache!!

[spharis]

I'll paste some links with info on porting later. Much more useful than me trying to type it out......has calculators too!

Use whatever fuse the manufacturer recommends in the install manual. For the main cable use the sum of the other fuses, or fuse to the wire size and length. Fusing to the wire is a much better option, but remember in marine, fusing is not as critical as in an auto where the whole chassis is ground. You could probably get away with just the fuses internal to the amps after the split. I wouldn't run any fuses, but that's just me. I figure why waste the money....I am not passing through a firewall, I am not passing through a metal floor tied to the ground.....no need to fuse. IF and that's a big IF....a wire chaffs or gets cut (although how would it unless you did it) it isn't going to short out to chassis ground. I am pretty sure you have a ginormous lack of fusing in your boat right now. Maybe some breakers on your dash for unfused items (bilge blowers, pumps, etc), but the power cables themselves probably are not fused previous to those breakers. The fuse for your amp would be doing the same thing as the breaker on your dash. Simple circuit protection to protect the unit itself, not the wiring. Fusing in an auto is to protect the wiring from shorting out and melting/fire/etc.

[Domsz06]

SPharris,

Talk to me about porting, as well as what size fuses should I use for my amps?

pcx-1500
pcx-4125
pcx-280?

Have 3 1500's, 1 4125 and 2 280's, going to run individual power wire to each of them, have a zer0 gauge coming in, split to 4 gauge. Having each one fused, what do you recommend?

Thanks.