The FPB 64s have a large day tank in the engine room. There are two 1/4HP geared pumps, used one at a time, that fill the day tank from the main supply. These pumps are also used for the fuel polishing system.
The logic and basic control components are the same as we have used for the past 15 years, and the system works as follows:
- There are a series of floats containing magnets which trigger reed switches inside a pipe within the day tank. The pipe reduces early triggering from wave action.
- One of the lower and one of the higher reed switches controls a latching relay. At the selected low point the relay latches closed (on) triggering a solenoid which feeds power to the selected pump. When the higher reed switch is triggered, it opens the latching relay which turns off the pump.
- There are additional reed switches for low alarm, 90% (high off), and high alarm, plus two extra switch positions. The on/off levels of the day tank can be easily changed to suit trim requirements (heavier or lighter dinghy for example). Manual control is also used during fuel polishing.
- Should the automatic system fail for some reason there are manual controls for each pump.
- The pumps can triggered on using the latching relay with a momentary switch at the inside helm (to keep day tank filled).
Posted by Steve Dashew (February 8, 2010)
