Breaker Vs. Fuse

[KellyC]

Hello all, as some you probably already know I am rebuilding a 67 Starcraft Islander and am in the process of buying things and was wondering the opinion of those that have done a wiring job. Not sure if to go with a fuse panel or go with a switch panel with built in push button circuit breakers.

With a fuse block I can run the wire from the battery switch to the fuse block and then to the assigned switches and then the device. I can get a fuse block with both a positive and negative buss built in.

With the switch panel with circuit breakers I would have to install a buss bar for both positive and negative circuits to run to the switches and then to the device.

Also, do I need to fuse the wire coming from the battery switch to the buss bar or fuse panel which ever I do use?

 

[LippCJ7]

Re: Breaker Vs. Fuse

Wiring wise there is no difference between a fuse and a circuit breaker other then when a circuit breaker blows they can be reset a fuse cannot, you can purchase fuses and circuit breakers for the same amp values. But.....how many new boats can you buy that have manufacturer installed circuit breakers? I will give you a hint, not many. I know that technology isn't always the answer but in this case it is(in my opinion), Use Fuses. On the buss supply wire some do some don't, I wire Police cars professionally and I do use a large resetable BREAKER on my main supply wires. The main reason for a resetable breaker is not only for protecting the wiring from the buss to the breaker but also to give me another place to disconnect voltage from the boat. This is the type breaker I use for this application, size depends on the total amps drawn from the buss plus a little bit extra.

 

[ajgraz]

Re: Breaker Vs. Fuse

I'm no pro, but here's how I see it:

If you got a ton o' money to spend OR are building some kind of either live-aboard or transoceanic vessel, get breakers. Otherwise go fuses.

And I agree with the above, got to protect the mains wire between the battery and the bus/fuse/breaker/box. Depending how many amps that's got to carry, a breaker there may be the best solution even if your individual circuits use fuses.

 

[Fireman431]

Re: Breaker Vs. Fuse

What he said...

I have done both in the past. Resettable breakers on ignition/starter circuits, master radio (VHF, GPS) circuits, and main lighting circuits. If something goes wrong with these on the water, you can fix the problem and reset to get home without worrying about not having the correct fuse.

Run bus bars for the other add-ons. I have a dual buss, which has a clearly labeled 12v+ and -ground circuit on the same board (clearly identified). Each circuit has it's own ATO blade fuse like an auto fuse box. I have a master inline 40 amp fuse in the 8 gauge wire that feeds the panel.

 

[Silvertip]

Re: Breaker Vs. Fuse

The problem with using a switch panel with built-in breakers is that the breakers have ratings that are generally too high. Fuses allow proper sizing for the associated wiring and load. Properly wired, fuses are not something that needs repeated replacement. Done correctly they should never blow. With a combination switch/breaker panel you also are limited in how the system can be expanded. Use an 8 or 12 circuit fuse panel and you have all the expansion capability you will likely ever need.

 

[KellyC]

Re: Breaker Vs. Fuse

Thanks for all the info guys, it is really appreciated. All everything that everyone has said is what I thought but I just wanted to make sure that I was going about it the right way.

I do have some experience with wiring but it is in the industrial sector and on just select equipment for a semi conductor manufacturer. For someone who deals with this kind of stuff only AC I seem to have a lot of dumb questions.

 

[j_martin]

Re: Breaker Vs. Fuse

Rule of thumb. The fuse or breaker is sized to protect the wiring. If a set load is on it (fish finder for instance) it can be downsized to protect the device itself.

All the small stuff on my bass boat, for instance, is wired with 14 or 16 G wire. All the fuses are 5 amp, except the circuit that supplies the fish finder, 3 amp. The 12G feed from the battery to the main switch is protected by a 20 amp fuse.

A mouse can dine on this sucker anywhere, and he'll kill a circuit, but he won't burn down the boat.