Question about Breaker systems

[grizzly1530]

I have a 16 foot v bottom aluminum boat. I have done a lot of other work with it, but the wiring is something that I plan to do this spring. As of this moment, my boat has a 4 gang switch box connected to a fuse block (I'm not even sure I have the lingo right). I have lights, nav lights, depth finder, livewell pump, bilge pump, and a 12 volt plug for a phone charger to connect. I was looking at getting a breaker system since I'm upgrading the wiring. When I search for marine breaker panels, it seems like all of them come as switches with breakers in one, and with 2) 5 amp, 2) 10 amp, and 2) 15 amp breakers. I looked at my depth finder and livewell pump and they suggest 3 amp breakers/fuses. I feel like the only thing I would need a 15 amp breaker for is the 12 volt plug. Am I getting this correct? The livewell pump is a 500 gph pump, and the depth finder is a Humminbird 698 ci hd si. The nav lights and interior light I feel would draw about the same. The breaker panel I'm looking at is something like this. Can the breaker sizes be changed in these?

 

[gm280]

grizzy, I am not familiar with that particular switch setup, but I would assume there are replacement circuit breakers that you could change. With that said, I wouldn't go for the exact current usage for each circuit. For example, if your bilge pump draws 3 amps, I would go 4 or 5 amp with the breaker for that circuit. Same with other circuits. If your navigation lights add up to 2 amps, I would go with 3 or 4 amps. Never fuse or use breakers for the exact amount of current the circuit will use. Inrush currents can surge over the amount for a few seconds and blow a fuse or pop a breaker. So go just a little over the current rating for each circuit, but never over the wire capabilities. That way you protect both the circuit accessories and the wiring used in the circuit. JMHO!

 

[kmarine]

I agree. That you want a little wiggle room.. Most pannels will allow you to change out breakers. Most cigarette lighters use 20. Amp fuse, 15 is enough for a cell phone charger, but you may want to go larger incase you want to run an inverter for 120 volt toys.

 

[grizzly1530]

Awesome, thanks for the help guys! I had pretty much everything else down, but I just couldn't figure this breaker thing out. I was starting to think breakers were for big cabin cruisers only, haha.