Wiring to a generator ( Water Maker)

merry xmass everyone, seems that some are recovering from all the festive food overdose by typing, so I'll join in.

water down here (even in the city) is awful, I do have a reverse osmosis system for home and I really enjoy the water produced.

in the local isles, getting water is often a bad joke.
In Skiathos port fe (the largest and most touristic of the three isles nearby) you have to first find a fcking berth. So, you have to be there by 4pm on certain days (Mon-Wed) that the charters are out to get one. Then the joke begins by trying to find the magic card, charge it and get the pilar to work and give some water out. Last time this August I just gave up after 3-4 h faffing about, begging, asking, bribing and turning cocks on and off. And all that got me couple of hundred of litres of the liquid.
If you are unlucky and you fail to get a spot there, you have to wait around the main wharf for the tourist boats to leave (5ish) and then moor stern to on the 4 births that are outside the port with all the blocks and rocks thrown in to protect the wharf. Furthermore, port ppl are quite unhappy if you do that as they'll only get 7euro for a night from my 12m, compared to 40odd for the 24+m mobos that often come. The price includes absolutely nothing - not even serious protection from the weather and the cat coming into port with 18kn doing a handbrake turn to tie up on the inside bringing an amazing wash. So no water on option B...

In Skopelos port, you better have 100m of hose to reach the end of the parade where there's a sole pilar operated by a local that you have to bribe to get some water.

In Alonissos, things are more civilised, you have enough pilars, you can easily get cards from the shop nearby and you have decent pressure to fill up your tank. Problem is getting a spot to moor in the first place :D

The above together with the fact that even with four of us (wife, daughter and son) I probably use 10lt a day, and each one of them if left unattended need 50...

So in order to avoid shouting to them all the time, annoying the wife and actually relaxing, I decided to fit a w/m and I'm now upping it from 30lph (which was pathetic) to 100lph + (hopefully)
Since I also didn't enjoy the two visits to the lazarette for starting it up, turning up the pressure to 800psi and then turning down the pressure and shutting down, I've also went through the hassle of replacing the 2KW 220V motor with a 3phase one, so that I have a decent soft start via the inverter and even setup a remote start/stop together with indicators so that I can just press one button to start the geny from the lower helm and another to start the watermaker a few secs later without even lifting the aft deck hatch.

Plan is to operate as per Hurricanes suggestion re battery charging, so each morning when I need to give a boost charge to the batteries using the geny, I'll produce the days worth of water. An hour and a half or every few days 2h should be plenty. The rest of the batteries charging will be via the solars and I could be in total silence till next morning...

so yes, in some areas w/m makes sense, marina hopping, in areas with plenty of water (and decent quality) no so.

cheers

V.
 
It’s seems water or the inability to top up is at the top or near the top of long stays out anxiety
We have all suffered water anxiety in the Med on tour .
I,ve seen some WM in modular formats - mainly for ease of packaging in small spaces .
How ever I have also seem belt driven H pressure pumps that can be attached to a main engine ,bit like an alternator set up .

Presumably some sort of tensioner like a ride on mower cutter blade action ?
So you pull it tight = activating the pump ?

Therefore may be ( especially if a lot of pootling is planned twixt anchorages ) that’s the way to go .
Say a modest 180 L/ h - real use say 130 L/ h — so 500 L during a 3 1/2 hr passage - sounds ok .

Just watch the water guage move to RHS as you cruise .:encouragement:

So for me 8/9 knots is approx 40 L/ h ( out of 2000 ) for 3 1/2 hours - moved 30 miles - that’s enough in a place like the Greek islands etc .Engines are runing any how so why not tap in to them to run a pump ?

Saves having to run the geny just for water - only Or longer after batt recharge? Is done .
I think if I was to go the WM route I would prob go down modular engine belt driven pump arrangement .
Not having to phaff with D.C. volatage / batt cap issues or reliant on geny extra time for ac , over the batt recharge?
There’s no one size fits all - depends how you use your boat I guess .
 
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PF, just bear in mind that pumps need to run at specific revs in order to produce the goods.
Mine needs 1750rpm, less will produce less water, more will damage the pump. So if you go for the clutch and pulley thing off the gbox or whatever, you got to be careful before you decide to floor it so to speak as it may cost you a grand in pump...

other than that, yep, sounds fine, but wouldn't do it on an itama tbh. you can spare 8-9A from your geny for an hour or so a day without the clutch and pulley complications.

V.
 
PF, just bear in mind that pumps need to run at specific revs in order to produce the goods.
Mine needs 1750rpm, less will produce less water, more will damage the pump. So if you go for the clutch and pulley thing off the gbox or whatever, you got to be careful before you decide to floor it so to speak as it may cost you a grand in pump...

other than that, yep, sounds fine, but wouldn't do it on an itama tbh. you can spare 8-9A from your geny for an hour or so a day without the clutch and pulley complications.

V.
Yes I think you are right .Theres a too bigger rpm range 8/900 pootle to 1850 30 knots @ which 3 1/2 hours hours moves me over 100 miles - to another country potentially.
Can run the geny anyhow @ pootle or any speed for that matter.
Would prefer reliability to be the Deciding factor .
So just a boggo ac pump - adds as MapishM says option of shore power fill if there’s a “water shortage “in a clean marina
 
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The Generator I assume ( Onan in a Squadron 58 2004 ) is probably not earthed anyway unless to the P Bracket ( and I can check this whilst on board) and the RCD works based on current imbalance - so it current "goes missing" it will trip.

If it is earthed then I will run three wires - Earth - Neutral - Live to the RCD.

I am also assuming that there is no impact on galvanic isolation by tapping into a generator feed?

As always answers on a postcard, and I hope the score is not an even 50/50!

Merry Christmas to you all


I'm fairly sure that your genny has neutral connected to ground inside ,
you can measure this;
while genny is running, between Phase and ground you schould measure 230VAC,
and between neutral and ground = 0VAC

if it isn't the RCD will NOT work,
the RCD will indeed react on current imballance between phase and neutral,
BUT, if the neutral is not connected to Gnd, you would have a floating supply, so in case of a phase touching ground, there won't be a leak current= no missing current, so the RCD won't trip = won't work

the place to wire that RCD:
interrupt the main wires coming out of the genny,

best wishes !
 
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