What size anl fuse?

[gride]

The system consists of a cmd3 h/u, clarion apx480m, kicker zx350.2, and maybe a jl m1400. I plan to use 4 gauge power and ground from the battery with a 150amp anl fuse on the power wire. I have a pair of distribution blocks that accept one 4 gauge in and four 8 gauge out. The power/ground wire is less than 15' each. The runs to the amps from the blocks is 6" or less. To the sub amp might be closer to 12-15". Should I fuse after the block or no? Also, is 150 anl to big? Thanks in advance.

[core-rider]

You really need to look up the info for each amp and see what they're individual power requirements are, then add them together and that should give you a minimum size fuse to use for the main power feed. Yes I would fuse the individual leads going to each amp, because if you had something go wrong with one amp it may not be enough to blow your main fuse possibly leading to a fire. I would recommend a fused distribution block that way you have less connections to make up. Also, depending on the current draw of those two amps, you may need larger than 4 gauge main leads.

[gride]

Just did some research. In total the 3 amps add up to 136amps. I would prefer fused blocks. What's the best value out there? There will never be more thAn these 3 amps in the boat.

[Chexi]

http://www.bcae1.com/

You are welcome.

[Chexi]

Here is what I use, but it can be hard to find.

http://www.mobilespec.com/p-86-digit...ion-block.aspx

[gride]

I've been on bcae1 and probably read the whole thing a couple times. Very good info. I'm just curious bc earmark told me I didn't need to fuse after the block with just the clarion and kicker amp using a circuit breaker at the battery; which corroded after two years. I've also read and heard breakers have different voltages at each contact. I'm definitely going with a fuse this time. So would I need to go to bigger power/ ground with 3 amps? I'm gonna have the stuff installed, but want to address everything with the installer beforehand so no surprises. Is 18 gauge ok for tower speaker wire running off the kicker amp?

[Mikeski]

Gride,

In this case you should upsize the wires to make up for voltage drop. 15' of wire to 3 amps, I would recommend 1/0. This 0.2 or 0.3 volts are precious when it comes to amplifier performance running off batteries. If you are operating the stereo only when the boat is running then I would suggest #2 minimum. Fusing is somewhat of a personal preferance. With my 1/0 mains they can handle all the current my battery bank can deliver so I have chosen not to fuse them. Once you get above 100 amps the safety provided by a fuse becomes very diminished anyway. You can start plenty of fires with a partial short arcing at less than 100 amps. Wire management and cable choice comes into play at this time. I suggest using marine rated cable with a heavy high quality insulation jacket. I am by far the minority but I avoid car stereo power cable. Keep in mind I am an electrical engineer working in the solar power field dealing with heavy DC currents on a daily basis so I might have a bit more experience choosing cables than most.

[EarmarkMarine]

With 15+15 ft runs for a total of 30 feet and 136 amps of maximum draw, I would also agree that you need a 1 gauge master feed before dividing into the distribution blocks. If your batteries and amplifiers were in the same locker you could get by with 2-gauge but your run is too long.
The master fusing is specifically for the protection of your boat and occupants in case of an accident. The surrounding materials and boat would catch on fire before a 1 gauge cable would burn through. Code says that the fusing should be within 7-inches of the battery. That's not always possible but get as close as you can. The master fuse can be barely below, equal to or the minimum above the collective fuse recommendations for your amplifiers. A 150 amp breaker at the source would be acceptable for a 136 amp total potential draw.
You can have corrosion with a fuse or breaker. If using a breaker make sure you have one with 5/16" posts (rather than 1/4") and make sure the terminal lugs are also 5/16" for a precise fit. The termination lugs should be well crimped on and soldered. Its not automatically easy to do with heavy gauge stuff. Stay away from that cheaper gold-splashed hardware. Use good nickel-plated connectors and hardware in a boat for better corrosion resistance.

David
Earmark Marine

[Chexi]

David, I have sent a couple emails to your site asking about some info and availability on Rev 8's. Please check the Earmark spam folder.

[gride]

Thaks Dave. I want to go with a fuse this time since it doesn't depend on moving parts, all be it a spring. What's a good fused block I can use for 3 amps? It looks like tsunami has alot of choices. How's the block that is power and ground along with fuse?

[EarmarkMarine]

Gride,
Most will place a master fuse or breaker closest to the power source (battery or dual battery switch) and use separate distribution blocks as close to the amplifiers as possible. Its cleaner and more cost-effective. One long heavy gauge run and three short lower gauge extensions. You don't need redundant fusing for the sake of the amplifiers. What is in the amplifier chassis is all thats needed for the protection of the electronics. We favor breakers above a certain threshold but I don't have any issue with using fuses instead. When it comes to breakers its about the quality that you use. You won't find fuses in a $2 million motoryacht. Just breakers. Buss is the only brand breaker we use. Never had a bad one yet. But we have experienced failures with a cheaper alternative so we quickly abandoned that course about 7 or 8 years ago.

David
Earmark Marine

[EarmarkMarine]

Chexi,
I don't have any record of contact. The general sales email has an issue.
Rev8s are in stock.
Try:
david@earmarkcaraudio.com
or
odin@earmarkcaraudio.com

David
Earmark Marine

[gride]

I did have a buss I purchased from y'all a while ago. One of the terminal posts broke off the other day when I was going to remove it and the breaker would not open when the button was pushed. No big deal.

[EarmarkMarine]

Kind of hard to break off a 5/16" post. But I'll have to ammend my statement to one bad Buss breaker.

David
Earmark Marine

[gride]

The breaker is down at the river. I'll put up a pic after this weekend. I tried to pry the switch open with a flat head and it wouldn't budge. Have the same one in my truck that's about 6 years old and it is in like new condition.