I know they say don't ever be tempted to install a higher breaker than necessary, since it won't trip soon enough, but could I go a notch higher in case I do upgrade my bilge pump or stereo?
Let me try to clear one thing up. IF you install a bilge pump and it states it uses 3 amps of current at 12 volts. You don't use a 3 amp circuit breaker and here is why. Any electric motor has what is called "in-rush current" at start up. And what that means is when you initially turn it on, it take more then 3 amps to get the motor turning .If you used a fuse or circuit breaker that just fits that run current requirement, it could pop or blow the fuse. Then you would think there is something wrong with the pump.
In a 3 amp circuit, I would use a 5 amp circuit breaker or fuse for that reason. The wire running to that pump usually handle a lot more the 5 amps. So if the motor did short out, it would draw a ton more current then 5 amps and the fuse or breaker would do its job without fail.
I do that exact same idea with each and every circuit I wire in. It allows a little extra current before popping or blowing a fuse. It still protects the wires, boat and everything else if a true short happens. Of course if a circuit calls for 6 amps, you don't use a 20 amp protection setup. I would use an 8 or 10 amp in a 6 amp circuit. Usually circuit breakers come in 5, 10, 15, 20 and so forth sizes. Yes you can buy them in every amp size, but I use increments of 5 with them, most of the time. Just me! But I also use the proper size (gauge) wires as well. Never use wire that just covers the amperage needed. Always use the next gauge heavier and you will never have any problems. JMHO
