Waterpump running constantly when tank empty

vas said:
J,

so how many mins is filling the bathtub? I guess that's going to be the limiting factor for setting the clock :D
Leaving aside the fact that the 1.5K pump does need "a few" Amps, I'm pretty sure it's going to be a v.easy job making this timer with any plc or 5euro arduino board. If you don't find a solution by autumn, give me a shout I should have time to play and put something together!

cheers

V.
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Nope, because pump cycles on/off when filling the bath due to the accumulator. Only time the pump pumps water constantly is when you have say 3 showers, bathtub, dishwasher, wash machine and some taps on altogether, which ain't gonna happen.

I think it says 36amps in the label. At 24 v. It has a relay mounted on it so I can switch it on the relay coil side. Thanks for the Vas-automation offer!

Incidentally, my pump just last weekend started cycling on/off v fast, like 1Hz, so I think accumulator has busted. I just ordered one online and will take the old one to bits to understand how it broke.
 
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BruceK said:
Does it do any harm to the pump though. They are capable of running dry without damage.
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TBH not really. The pump does get hot though and I'd rather not add so much wear to the whole thing. I'm probably being over fussy. TBH I dont know what pumping principle it uses- not diaphragm afaik and does not look normal shape of a centrifugal pump, but is able to run dry
 
jfm said:
Incidentally, my pump just last weekend started cycling on/off v fast, like 1Hz, so I think accumulator has busted. I just ordered one online and will take the old one to bits to understand how it broke.
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If you find anything that we should look out for, maybe you could report it on here?
There is always something new to mend in boats!!
 
You can get 24 volt timer relays, you wire one in and set the timer portion to the time you like which is usually up to 30 seconds for most commercial timer relays.
 
jfm said:
The problem I'm trying to solve is continuous pump running which only happens when water tank is drained. E.g. You put dishwasher and washing machine on with (by mistake) only 1/8th tank of water and leave the boat for the day
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See post #35. We have two different J's here and two different issues!

Vas surely had the correct solution to the JFM (and my issue) and that would be to disable the pump when the water level drops to a certain level.
 
jfm said:
The problem I'm trying to solve is continuous pump running which only happens when water tank is drained. E.g. You put dishwasher and washing machine on with (by mistake) only 1/8th tank of water and leave the boat for the day
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or eg someone leaves a tap dripping and the tank empties 3 days later. Yes i should turn the breakers off when I leave the boat but I never bother.
 
Mine seems different , the pump run switch mechanism is on the faucet side .
It only runs when it detects one open .

It does not start running if the tank is empty .

We have a switch on the control panal ( like everyone? ) and turn this off when the boats left .
There’s also a push button priming button you can press to run the pump without opening a faucet.
Led by there sides so you can see them come on when the pump runs .

Had a gnaneschi ( sp ?) with an accumulator, which tbh was noisey then it packed up .
It was replaced with what we have now which reckons not to need a large accumulator, instead it’s got this rapid detection of faucet open thingy .
More or less same sound btw .

Tank is 500L 1/2 a ton .
Makes a big difference ( old sunny had 170L - just inadequate imho )
I have a water guage on the helm so just like fuel try not the run it too low .
Lasts 4-5 days with two on board .

Advantage of a sudden runing reactive if you like pump is that if you have a leak it detects it like a dripping tap and pulses straight away .
Where as an accumulator may seep out water silently, then pulse , but because of a few folks on board you assume somebody’s operated a faucet , or if they do they are just topping up the accumulator tank before it’s dropped low enough for say when you are all sat together to realise nobody’s running a faucet and the pumps running .

I had two leaks
One was a crack in a push fit “T” in the ER .
I just now and agian found a pool of fresh ( tasted ) under an engine - just assumed overzealous boat washing and somehow water ended up there .
I was fiddling about one day pressed my arse against it then found it .
So another trip to DIY store for a 15 mm push T .It was not the o ring it was the actual body - middle of the T

Water pump would pulse if you pressed and the crack opened - leak .Perhsps when running vibrations opened it , but you would not hear the pump anyhow , just see water - from somewhere??

Second - Son and I were just packing up to return a hire car to the airport and I herd the pulsing , first once then silence , then another say 10 mins , gradually the time interval decreasing .
Obviously asked if he,d turn off taps etc and go and check .
Opened the vanity cuboard in the master bathroom and saw water leaking out or a 15 to 6 mm reducer for the bidet .
Must have just started .
Then a bilge pump started nearby .
30 mins just before we were about to set off home - great .!

Luck would have it it was a o ring on the 15 side and I happened to have a spare -
Talk about the pressure is on !!
Even though we turn off everything except bilge pumps and the main charger , it’s not something I would have felt easy about leaving a leak .

What I,am saying is your pump tells you you have a leak quickly if no accumulator.
 
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Yup as jr says you have to leave your pump on if you have a modern type water maker.

@ Porto, no-accumulator only works in small boats with one (maybe 2) bathrooms. In a larger boat accumulators are essential. You need a big water pump that can feed multiple baths, showers, dishwasher, etc, simultaneously, but if there is no accumulator and you open just one tap and the big pump fires up (slowly, because it has inertia) the result is messy and the pump cycles much too fast.
 
Assassin said:
You can get 24 volt timer relays, you wire one in and set the timer portion to the time you like which is usually up to 30 seconds for most commercial timer relays.
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Do you have a link assassin? I can't find one that works on say 5 minutes, which is what this needs. 30 seconds isn't enough.
 
jfm said:
Do you have a link assassin? I can't find one that works on say 5 minutes, which is what this needs. 30 seconds isn't enough.
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John, I bought three variable seconds to 6 hour relays for our boat from these guys-
https://www.autoelectricsupplies.co.uk/mobile/product/1146

Work well for me but not sure if it’s right for your needs.
I have ours set to run for a few minutes as the switch in the shower pumps on demand and Lagoon standard fit with a 15 second non variable relay!
 
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jfm said:
Do you have a link assassin? I can't find one that works on say 5 minutes, which is what this needs. 30 seconds isn't enough.
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This was the point I was making, some only time up to 30 seconds and these are sequenced start relays usually, you need the programmable type which are readily available from most machine automation electrical suppliers in your area as these can usually be programmed to operate from 1 minute up to 4 hours, go really high tech and you can get them with digital readouts.
 
jfm said:
Incidentally, my pump just last weekend started cycling on/off v fast, like 1Hz, so I think accumulator has busted. I just ordered one online and will take the old one to bits to understand how it broke.
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Check the pressure in the accumulator tank. It should Ben slightly below that of the water pump.

They can fail, damaged bladder causing water to leak into the air chamber or an air leak from the chamber causing loss of pressure.

It could also be a pump fault or air leak in the pipes on the low pressure side of the pump (pre filter housing leak is common).

If fitting a new accumulator remember to set pressure via the valve on top of the tank. Trial and error way is to turn on taps, release pressure from the tank and measure time for pump to cycle. As cycle time quickens increase pressure, time will slow again and then quicken as more pressure is added. Let out air until you reach the sweet spot.

Probably teaching my grand mother to suck eggs :)

Henry :)
 
Many thanks

@nigel, thanks, but as I read the data sheet (happy to be corrected) that relay doesn't perform the function needed here. @assasin, thanks also, and that Rockwell relay does the job perfectly in "power on one shot" mode :encouragement: Thanks also for the pm. I'll find a distributor and buy one.

@henry, thanks, and it wasn't egg-suck teaching - I know the principles but haven't changed one before. My main suspect is the tank membrane and the new tank has already arrived. All noted re the pressure set up though my hope is that I can just swap the tank and leave the pressure switch set as is - they're separate components. I'll see how it goes.
 
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