AC wiring flaw
DC wiring flawRecall we have FOUR electric bilge pumps. Two in each sump, fore and aft. In each pair, one is a "Crash" pump (expensive, high capacity for that time when you have a really BIG leak, hopefully never), the other is a "Dry" pump (cheaper, low capacity, for keeping the bilges dry). They are mounted such that, the dry pumps start first, and then, if water ingress is overpowering for the dry pumps, the crash pumps kick in.
My original wiring had all pumps powered through one 24 volt buss, which in turn was powered through one Mastervolt channel.
Well, a few weeks ago, something happened to the forward "dry" bilge pump causing it to overload the circuit (stuck impeller or something). This caused an overcurrent condition in the Mastervolt system which, in response, shut down the circuit. Now the 24 volt buss has no power, along with all the other pumps connected. I think you can see the flaw.
If one were in a real emergency, where the boat was taking on water, the last thing you want is one of the cheap low capacity pumps to fail, and take out the rest of the pumps with it.
Furthermore, as handy and fancy as the Mastervolt system is, I don't feel comfortable having it be the SOLE source of power for the bilge pumps. Some sort of electrical bypass is necessary in case the Mastervolt system goes down.
The solution is to wire all four pumps into the Mastervolt system, each with their own channel. Between the channel output and the (physical) pump switch, each tap into the positive side of one circuit of a multi-circuit fuse block. The entire fuse block, in turn is powered directly from the battery terminals, through an override switch.
The result is that, should the Mastervolt system shut down, turning on the one override switch will energize the fuse block, bringing all pumps back on-line.
Pretty easy huh? Like I said, "What was I Thinking?" when I originally wired this thing. Oh well, best catching this now instead of waiting for a true emergency situation.