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Do I need a fuse/breaker here??

W

wild.coast

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In terms of wire runs, battery to main ON/OFF switch is about 2m (6ft) and engine to switch is about 2-2.5m as well.

The outboard technically has a fuse box so I'm assuming it's not needed there, correct?

Between battery and switch, I'm assuming this IS important? It's a big wire with a lot of power going through it and would make a heck of a fire if it burns and all that rubber jacket goes up in smoke. It's also running along the length of my RIB (think rubber pontoons that are instantly damaged by any fire) - so any fire would be instantly a sinking situation :S
 
Also, am I correct to wire the engine negative wire to a negative bus as shown? Or should I wire it directly to the battery?

I guess if it's wired to the -ve bus it would mean the bus has to handle the appliance load coming into it (76A) PLUS all the current from the engine cranking when it first starts, I don't even know what that looks like in AMPS...

The main reason I didn't wire it directly to battery is because my boat layout is Engine-Console-Battery -> i.e. battery in the bow and console with the on/off switch in the middle. So going directly from engine to battery would be a 5-6m run, while the engine positive would only be to the console and 2m.
 
Ok, so after some more research found this very helpful vid:

Looks like ABYC code is to NOT fuse the ignition circuit. Basically, current can go up a TON when cranking, especially if trying to start engine on a low voltage (drained down) battery. And they basically picked the more likely of the two risks: better to risk having a somewhat unlikely short vs not being able to start engine when you REALLY need it and not being able to b/c of a blown fuse!

So the two arrows labelled ign (ignition) are fine unfused. But what about slightly downstream - should I be fusing the length of cable between the ON/OFF switch and the +ve bus bar?


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