I'd like to have my hot water heater only heating under 2 circumstances: 1) the boat is connected to shore power or 2) as a dump load for the wind generator, when the batteries have reached a preset voltage.
This is what I'm thinking. Can anyone here add some insight to this?
The relay is something I'll put together that is normally open connecting the dump load controll, but when shore power is connected it will close to allow shore power to connect to the hot water heater.
I am not planning to get a 12v element for the hot water heater. I will have some loss when the wind is heating my water, but it will mean that I'll have the flexibility of connecting to shore power (oftern in winter/spring, extremely rare in summer/fall).
Circuit breakers are not shown. I need to look at the existing box and see if I can rewire just the breaker for the hot water heater, to disconnect it from the normal input and connect it to the relay. Or I may need a separate box altogether for the hotwater heater -- or use a fuse maybe to save room.
The normal input for the circuit breakers will now be connected to the inverter/charger instead of shore power.
The dump load controller will be a Xantrex C60 (which I already own) or a Flexcharge. I don't know if the Flexcharge or the C60 will NOT open and close rapidly as the voltage hovers around the preset voltage or if they will have some hysteresis and open/close more gracefully. I'll have to see how that goes.
Any thought on this?