I have had auto flush arrangements on my last two yachts - both cost upwards of $1500 to have fitted.
I am looking for an economic and safe alternative.
As far as I can see they are simple enough arranngements involving a 12V timer and a solonoid valve which can readily be bought for less than $50.
So to fitting…..
I have a Xantrax lite meter and shunt fitted to the negative terminal of the batteries. I assume that goes to a negative BUS. + from the batteries goes to the isolator and from there to a + BUS.
As far as I can see the wiring
for the autoflush should be as follows:
1. Connect lead from battery
+ terminal direct to the timer
2. Connect lead from - BUS direct to the timer
(in that way the meter should still measure battery
3. Connect lead from negative and positive terminals above to the timer;
4. Connect switced negative and positive terminals from the timer to the solenoid, fresh water
pump and water
maker (in series of in parallel??). The timer is rated at 16A so should be fine.
Am i correct so far? If so my question is can one connect the leads from the timer to the fresh water pump and water maker together with the existing leads running to the main panel. Each is obviously switched and usually only works when the isoloator is on and switched on at the main panel.
Is there a need for any sort of relay?
The end result hopefully being timer switches on, opens the solonoid valve. turns on the main fresh water pump (new parmax 4) and the water maker - which if left in the flush position should backflush the water maker every 5 days (or how ever often I want to set it if more frequently).
Does anyone know what for example the Ocean autoflush unit from New Zealand
offers beside this - apart from a good looking little, if quite pricey, unit that does exactly what I have described for $750 + cost of a sparky.