While in Emerald Bay I was able to determine that the main power switch had developed some additional resistance (about an ohm) which under high load could have gotten hot and caused the power system to fail. I bypassed around the switch and used the spare switch for the unused inverter connection to get back underway and when I got home was able to find a near drop in replacement. The contacts are rotated 90 degrees so had do do a bit of work to get it all to line up. I may shift to remote contactors in the future to allow for a cleaner for the high amperage connections. The first step will be to bring the main power feeds up from the batteries to the bulkhead in this locker for fuses.
There is still quite a bit of cleanup to do. However, that will wait until I am putting in the new inverter / charger and I can clean everything up at once.
Prior to replacing the house bank master switch, there is a wooden cover which protects this area. Off to the left there is a large electronically resettable circuit breaker for the winches and there are a couple of automatically resetting circuit breakers on the power feed. Interestingly the shunt for the mobitronic power meter is in the positive side of the circuit rather than the negative side as most systems have. Below we see the fuel feed and return for the main engine and generator with the shut off valves for the feed side. There is a hole down below which has been covered which had an unknown purpose. The furthest right switch is for the house circuits, the next to the left is the winches, then the generator, and finally the main engine. It is important to remember that the generator is running on an independent 12V battery rather than 24V as the other three switches are running.
This is a closeup of the house bank switch. To the left is the positive shunt bringing power up from the house bank, at the top is the connection to the house circuits and going out of the image to the left is the winch circuits. Note that the way this is wired the DC connection to the battery charger, bilge pumps, and other always active circuits are connected to the battery with independent fuses in their circuits.
Generator master switch is in the center of the image. Note that this circut shares a common ground with the rest of the equipment on the boat but that the voltage is only 12V rather than 24V like the rest of the power in this cabinet. I would like to put some kind of independent box over these terminals because there is 12V of difference between these posts and the 24V posts nearby which would apply 24V across the terminals of the 12V battery if there was a short.
Main Engine switch and electronically resettable breaker for the winches. I am not sure that the resettable breaker is working quite correctly. It might be a wiring issue, everything is fused, I think the intention of this was to be able to disable power to the winches unless they were actually being used which is a very good idea and then have an overload breaker to shut them down if for example too many winches were being used at the same time at high load.
Here the new house bank switch (to the right) has been installed, note that the switch has the same look on the front side and is compatable with the existing keys but the back has been rotated 90 degrees to have the switch turn on and off the same way.
Closeup of replaced house bank switch