electronic float switch, 2 WaterWitches later, need something more reliable, Ideas???

[vas]

right, afternoon all, hope all safe and tucked at home!

I don't seem to have much luck with float switches and I don't think I'm the only one tbh.
Anyway, have a Whale 16lt grey water tank for the two heads' sinks and shower connected to a gulper 220. Being working fine but has "used":
The original el. whale switch in the first two years (died open, pump wouldn't operate and overflow in the bilges...)
a waterwitch that I replaced the original with in the next two years (died close circuit, pump wouldn't stop running!)

At some point during the rebuilt I bought a load of these waterwitches (4 24V ones) and I'm now down to to. Thought OK, will replace the dead one with a brand new one still in its wrapping.
Bllx! fitted it same thing, runs constantly.

Now, I'm not an idiot at electrics/electronics although I've done some idiotic things in the past.
Am I missing something, or is the brand new one also dead??? Searching the web, came across a 2010 thread on PBO with same issue
Don't mention the 5 or 7y warrantee, as they are stamped 2013 and I have no proof of purchase from back whenever I bought them.
Pump runs, Voltage is fine, I guess internal resistance of pump el.motor must be fine else it wouldn't work, so what else could go wrong?

I'm seriously considering getting these swimming pool switches, cut out all the crap out of the whale lid, drill a hole and fit one, cannot go much wrong with them.
Mapis mentioned an Italian firm producing some quality switches Gavazzi (ILSP2 and ILSP8 can switch 3A), couldn't find anything on ebay or locally (and cannot search locally anyway now)
Other issue is that most ebay ones are only rated to half Amp and not 1.75A of the gulper running the thing!
this sort of thing:
Stainless Steel Vertical Water Level Sensor Float Switch High Quality Free Post | eBay


Ideas considered!
also thinking of opening up the one I have and see what it looks like inside, well wont be easy as it's cast in some sort of black epoxy, but have so many hours at home, new projects welcomed

cheers

V.

 

[BartW]

Hi vas,
in BA we have quite a few float switches ao for alarm systems,
there is just one that breacks nearly every season, and thats the one from the backup bilgepump in the U/R, this one switches on and off occasionally,
the bilgepump is directly connected to this floaterswitch, and there is a fairly high curent through the contact !!
for this bilgepump I curently use the " Rule Super switch" rated for 20amps
all other bilge alarms are the standard "Rule-a-matic" floater switches, no frequent problems with these.


for the blacktank alarm I use this model; (all plastic)

this works succesfully for quite a few seasons,
but its important to know that the curent for the alarm signal is neglectible

same model is used for the grey tank signal (trigger for the pump timer, also neglectible curent)

 

[vas]

I see the issue with the Amps Bart, but mind, the WaterWitch is rated at 20A ffs! gulper is only 2A
Don't want to get into a signal, relay, pump setup as I add yet another element that could potentially fail (and wil...)

Further, I need something that hangs from the top like in your black tank, do you remember brand/info on it? There are loads all plastic and 5-10euro, tempted but the rating is holding me back!

V.

 

[kashurst]

I have installed one of these in the shower pump out box. You need a double pole relay as well to make the relay latch on when the high float lifts but keeps the pump runnings until the low level float drops down. Seems to work a treat. Its just two magnetic reed switches inside a plastic tube with the electrical connections well away from any water. I used a 20 Amp relay on a plug in base so if the relay fails it's 2 secs to swop it.
It also stops any annoying "oscillation" problems when the pump stops and the remaining water in the pipes runs back into the sump.
HALJIA ZP10010-2 Liquid Water Level Sensor Vertical 2 PP Float Switch Tank Liquid Water Sensor Dual Floating Switches White: Amazon.co.uk: DIY & Tools

 

[BartW]

that model I ordered from Ceresoli in Fiumicino (Rome) quite a few years ago,
does not have a brand name, and can't find it in their latest catalog,
and ceresoli doesn't have a online shop, let alone they are open right now,

googling float switch didn't bring much info either

 

[Refueler]

I have had two Waterwitches and BOTH ended up running continuously .... and I'm only using with a common low volume bilge pump ..

I've given up and now use an all in one float switch pump ... no way am I going to pay good money for a WW again ...

 

[Rappey]

Having had many open boats on moorings and my fair share of leaky wooden boats i have certainly got through many a float switch and bilge pump... A failed float switch in the on position kills the bilge pump and flattens the battery .
Tried an expensive solid state switch with stainless contacts, which when wet trigger the pump.. that thing ate itself through electrolysis !
Now i think i have the perfect solution, little pricey but got one on ebay for well under half price..
Jabsco Rule 39 Bilge Switch 12V, Air Operated Bilge Switch
The water level rises up the pipe, compresses the air inside which triggers a micro switch, turning on the pump. "20A and not a single moving part anywhere near water.
In our cellar sump we have a stuart turner float switch.. Plastic float on piece of string, micro switch in box way above.. Float and string rises, weighted arm triggers microswitch.. simple but extremely reliable as its been working for 28 years now ! All that water then gets pumped into 4 large water butts, then used for toilet flushing, watering garden etc

 

[Refueler]

Having had many open boats on moorings and my fair share of leaky wooden boats i have certainly got through many a float switch and bilge pump... A failed float switch in the on position kills the bilge pump and flattens the battery .
Tried an expensive solid state switch with stainless contacts, which when wet trigger the pump.. that thing ate itself through electrolysis !
Now i think i have the perfect solution, little pricey but got one on ebay for well under half price..
Jabsco Rule 39 Bilge Switch 12V, Air Operated Bilge Switch
The water level rises up the pipe, compresses the air inside which triggers a micro switch, turning on the pump. "20A and not a single moving part anywhere near water.
In our cellar sump we have a stuart turner float switch.. Plastic float on piece of string, micro switch in box way above.. Float and string rises, weighted arm triggers microswitch.. simple but extremely reliable as its been working for 28 years now ! All that water then gets pumped into 4 large water butts, then used for toilet flushing, watering garden etc

Funny you mention cellar ... my house was a KGB Interrogation building many years ago and the cellar was built with 10 cells .... and in one corner is a well. This overflows and floods the cellar causing extreme discomfort to those locked up ...
They used to have blocks to stand on to stay out of the water ....

There is a similar setup that has been preserved in Lithuania ...

Anyway - I bought the house and we removed the cell parts which previous owner had used for vegetable storage but never cured the water problem. So I put in a float controlled garden pump .... basically its an irrigation pump with a short cable to a mercury switch in a plastic box. Box floats up and switch closes contacts and pumps starts.
Funny enough - last week it decided to stop working so each day for about 4 days - I was trying to fix the pump in position to let float do its work ... the well is only about 1m diameter and that if not set right interferes with the float.

 

[alt]

My Grey water is tiny (shower only).

Originally, it was a traditional float switch that kept getting gunked up (and filter clogged).

Thought a WaterWitch would be a great idea - first one lasted approx. 6 months, same as the 2nd. Got sick of it and dumped it.

Bought a gulper and just tell people to turn on the pump when going for a shower (they can run dry, as i'm sure you know).

It's not ideal, however for the inconvenience of guests having to flick a switch on their way to shower, it saves me a LOT of potential grief.... no brainer for me!

 

[vas]

took me a while, but i'm back with a formulated idea which I'm going to develop and test!

first of all thanks for all the replies.

It turns out that Waterwitch is not that safe and long lasting, so not getting another one anytime soon!
Low tech option is what kahurst is using, double pool float thing wired to a 20A relay, will get a couple of float things to test as I have a drawer full of 10-20A square 8-pin old school relays from the old stabilisers controller. Issue is I got to get the range right else tank is going to be half full all the time, or empty and only use half the volume or less if I get it wrong - feel I need a longer range between on and off, will test onboard when I can.
High(er) tech option is to get an air operated thing. 70euro I aint paying though!

Yes, you'll notice I'm discarding the classic float switches, I've got a couple more as spares for when the e/r bilge one dies, not planning to use them for my grey tank/not suitable anyway for a 16lt tank!

Now, checked my boxes and drawers of goodies and what I've been using, cross checked with a colleague who is el/eng and always verifies what I'm about to do and he agreed so plan is to:

A. get a few analog output differential (most likely) pressure sensors (capable of sensing 0-4kPa MPXV5004G or 0-10kPa MPX5010DP). 10kPa is approx 1m head, 4kPa is .4m or so, grey tank is not higher than 300mm I think
B. get a single analog comparator chip like MAX931EPA (I have a few dual comparators in my drawer anyway)
C. get a bunch or resistors and a 1 or 5KOhm potentiometer to test voltage divider to get the right signal to the comparator
D. get a solid state relay - got 5 I think left over nice Chinese crap, rated at 40A (but according to some reviews/tests I checked after buying them) should be OK at 2A for a minute or two at a time
E. use a solid state 12-30V->5VDC transformer (got a dozen leftover) to drive the whole thing
F. get half a meter of 6mm transparent plastic tubing
[In theory I could replace the solid state relay with a transistor beefy enough for the 2A, but I don't have any such transistors and then i'll be stuck with my solid state relays trying to find something to do with them...]

Wire them all up (thermosilicone the chips/wires just leaving the pot screw visible), drill a small hole on the whale tank lid and get the tube in the grey tank
trim the pot so that pump starts when water is up close to the top of the tank
job done!

due to the lock-up it will probably take me a while to get the pressure sensors from Farnell (cannot get them locally unfortunately), once tested will report back. Would be nice to get a less accurate and much cheaper pressure sensor as the ones mentioned above and mainly the MPX5010DP which has a decent 450mV/kPa output is 13quid which I find a lot!
I bet it works and for sure will be a much cleaner solution to what I'm using atm and unlikely to fail in 2 or 3yrs time
Not to mention that I could integrate that with my yet to be built Tecma control dash and have black and grey water tank levels shown on a small 5in touch screen on the heads above the tecma.

we shall see and I'll report my results here

cheers

V.

 

[Refueler]

Years ago - I modified a Smoke Alarm to be a Bilge alarm ..... by connecting a lead to the test button. The bare ends of the lead when water touched - closed the circuit as if you pressed the TEST ...
Initially I did not think it would work as the water would be near fresh from rain etc. But it did.

So taking such a device - I'm wondering if the alarm output can be used to operate a relay ?

 

[vas]

So taking such a device - I'm wondering if the alarm output can be used to operate a relay ?

possibly, wires running a siren, should be okayish to run a pump, 2A is a lot though, so maybe you need to add a relay there to make sure you don't burn anything.

V.

 

[Refueler]

possibly, wires running a siren, should be okayish to run a pump, 2A is a lot though, so maybe you need to add a relay there to make sure you don't burn anything.

V.

I don't think the smoke alarm could run a pump direct - it really needs a relay so the alarm activates a relay to provide the 12V supply.

 

[Plum]

I've been using a washing machine water level switch for 5 years. It needs a relay to operate a pump. A half metre length of 13mm bore hose, one end at the deepest part of the bilge , the other end, 500mm above connect to the washing machine water level switch which is triggered by the increased air pressure as the water level rises. The switch never sees any water, always dry, reliable.

Www.solocoastalsailing.co.uk

 

[vas]

I've been using a washing machine water level switch for 5 years. It needs a relay to operate a pump. A half metre length of 13mm bore hose, one end at the deepest part of the bilge , the other end, 500mm above connect to the washing machine water level switch which is triggered by the increased air pressure as the water level rises. The switch never sees any water, always dry, reliable.

Www.solocoastalsailing.co.uk

interesting!
any idea how much water it needs to fire up?
I can find in ebay washing machine pressure switches for a tenner

 

[kashurst]

I've been using a washing machine water level switch for 5 years. It needs a relay to operate a pump. A half metre length of 13mm bore hose, one end at the deepest part of the bilge , the other end, 500mm above connect to the washing machine water level switch which is triggered by the increased air pressure as the water level rises. The switch never sees any water, always dry, reliable.

Www.solocoastalsailing.co.uk

great idea - how deep does the water need to be to operate the switch?

 

[mikegunn]

I've been using a washing machine water level switch for 5 years. It needs a relay to operate a pump. A half metre length of 13mm bore hose, one end at the deepest part of the bilge , the other end, 500mm above connect to the washing machine water level switch which is triggered by the increased air pressure as the water level rises. The switch never sees any water, always dry, reliable.

Www.solocoastalsailing.co.uk

I've done the same. Most of the pressure switches primarily designed for washing machines have some limited adjustment, both for pressure head and hysterises. I set mine to come on when the pump is covered by water, about 200mm. I have also installed a second float with a magnetic reed switch at approximately 300mm height wired in parallel. Both switches actuate the pump via an automotive relay which can handle 40 Amps. Incidentally I slid the flexible hose from the pressure switch into a length of plastic tube to prevent it kinking. IIRC the whole setup cost less than £20.00 and that included a box to house the relay.
Mike

 

[Plum]

great idea - how deep does the water need to be to operate the switch?

With my 13mm bore hose (a piece of garden hose) the switch makes when the water is about 120mm deep. I have the hose in the skeg moulding which is quite a small area so it doesn't need much volume of water to get to 120mm deep. I did not fiddle with the switch adjustment screws. I only paid £10 for the switch on eBay. You will need a relay to operate a pump but I do not have one as I only use it to trigger a warning light and buzzer at the helm.

Www.solocoastalsailing.co.uk

 

[Plum]

interesting!
any idea how much water it needs to fire up?
I can find in ebay washing machine pressure switches for a tenner

See my post #18

 

[omega2]

right, afternoon all, hope all safe and tucked at home!

I don't seem to have much luck with float switches and I don't think I'm the only one tbh.
Anyway, have a Whale 16lt grey water tank for the two heads' sinks and shower connected to a gulper 220. Being working fine but has "used":
The original el. whale switch in the first two years (died open, pump wouldn't operate and overflow in the bilges...)
a waterwitch that I replaced the original with in the next two years (died close circuit, pump wouldn't stop running!)

At some point during the rebuilt I bought a load of these waterwitches (4 24V ones) and I'm now down to to. Thought OK, will replace the dead one with a brand new one still in its wrapping.
Bllx! fitted it same thing, runs constantly.

Now, I'm not an idiot at electrics/electronics although I've done some idiotic things in the past.
Am I missing something, or is the brand new one also dead??? Searching the web, came across a 2010 thread on PBO with same issue
Don't mention the 5 or 7y warrantee, as they are stamped 2013 and I have no proof of purchase from back whenever I bought them.
Pump runs, Voltage is fine, I guess internal resistance of pump el.motor must be fine else it wouldn't work, so what else could go wrong?

I'm seriously considering getting these swimming pool switches, cut out all the crap out of the whale lid, drill a hole and fit one, cannot go much wrong with them.
Mapis mentioned an Italian firm producing some quality switches Gavazzi (ILSP2 and ILSP8 can switch 3A), couldn't find anything on ebay or locally (and cannot search locally anyway now)
Other issue is that most ebay ones are only rated to half Amp and not 1.75A of the gulper running the thing!
this sort of thing:
Stainless Steel Vertical Water Level Sensor Float Switch High Quality Free Post | eBay


Ideas considered!
also thinking of opening up the one I have and see what it looks like inside, well wont be easy as it's cast in some sort of black epoxy, but have so many hours at home, new projects welcomed

cheers

V.

Water Witch FAQ
Too much s---te on it??