Now you’re getting closer to
my main panel*... except I’ve got 8-gauge wire to the house. But no independent switch for the engine. Some people have one so that the alternator or starter can be serviced without turning off the rest of the boat.
There is more than one logic pattern that can be used -they just have to be internally consistent and obey the rules of amperage.
For example, I’ve never liked the bilge-pump hard-wired to a battery logic. If that battery were dead, I’d like to be able to switch it (and, say, the radio or the engine) to an alternate source. Of course, you could always grab a 1/2” wrench and swap cables around in a pinch. If you aren’t in a hurry.
*I’ve got a main hot buss supplied by fused battery cables, then high-amp breakers for the main branch circuits: House, Windlass, SSB radio, AC Inverter (some added since the linked pic). The fuses at the battery terminals protect the cable to the engine, so it doesn’t have anything else. Some Blue Seas panels have sufficient capacity that a separate “main” panel like mine isn’t needed. (Except the SSB doesn’t like to share.). I guess the moral of that story is that spending the big buck$ up front might avoid complications that can arise down stream if you build things piece-meal.
My main switch determines which bank is
used. For everything. The high-amp breakers can disconnect branches that aren’t wanted on. Still trying to get my head around whether switches are needed to shut off the various power
sources. Alternator, battery charger, solar panels, wind generator... all feed in to the main buss, though all have independent regulators. And then there are complications like charging relays, DC/DC chargers, etc.
Oh, and now that I’ve drunk the LiFePO4 cool-aid, even the
batteries have their own controllers. And none of these controllers talk to one another, unless you go sole source and/or have a custom-made system. One hopes that some sort of industry standard specification will evolve to make things simple again.
Oops: Should have linked
this post to show the wiring. The small wire in the box is the bilge pump circuit. It has its own breaker on a panel less than 12” away. But arguably, it might be better coming off an appropriate breaker of the house panel. Except that would mean a longer wire run.