My 15.75 x 30 Jemez Cabin

[MountainDon]

How well it works is still to be determined. I now have all the parts. Next week will see the installation. A report will follow.


Power requirements are minimal. The board operates on 9 volts. This gauge  will not be left "on" all the time. The plan is to press a momentary contact push button switch when we want to determine the cistern level. One reason for this method is to permit use of a 9 volt dry battery; one should last a couple years.  The other reason needs more explanation. These work by measuring very small current flow between the common contact in the bottom of the cistern and another contact further up the level. The circuit uses DC power. DC applied through a water medium will cause electrolysis which will cause contact erosion. It's the same problem boats encounter with their metal hulls when there are electronics aboard. IF the board used AC power at the contacts the electrolysis issue would be greatly reduced, pretty much an non-issue. However, those circuits are more complicated and boards are not readily available cheaply. So, I'm using DC.

[MountainDon]

Here's the diptube. That's 1/2" CPVC pipe, cross drilled to accept 10-24 brass machine screws. Contact sensor points in 4 positions. The bottom one for the common and three others with the highest being at the approx. 3/4 mark.



18 gauge solid , 4 conductor irrigation wire.



My cobbled together support for the diptube. A bulkhead fitting in the cistern neck to permit the wire to exit the cistern. Just a drop in fit through the tee to hold the diptube more or less plumb. Easy to pull if the need ever arises.




The assembled plastic case. It has a gasket to provide weather resistance. Push button, momentary contact switch is waterproof. Sorry for the glare. A piece of foam rubber under the battery keeps it in place pressed against the cover.



Test in a glass of water. It indicates full!  Other pictures show 1/2 and 1/4 but it would be boring to show them all.



If all LED's are lit we know the cistern is 3/4 full or better. If only the yellow and green illuminate we know we are somewhere below 3/4 but better than half. With the red only illuminated, somewhere between just under half and 1/4. No LED's the battery is dead or the water is below 1/4.  I was thinking of adding a battery test button but did not.  Perhaps I'll add that later, perhaps not. Next time I'll show it installed on the cistern.

[MountainDon]

..... with most of the orchard dead I can't see running out of water too soon now.

Oh dear!  I must have missed that note if you mentioned it anywhere. Sorry to hear about that. Was it winter kill?

[OlJarhead]

Oh dear!  I must have missed that note if you mentioned it anywhere. Sorry to hear about that. Was it winter kill?

Gopher kill   So far only 3 of 8 trees survived.  I posted some pics of the damage.  Pretty disappointed.

[MountainDon]

Water system changes all made and it works!

The cistern level is mounted inside above the kitchen sink. Alongside is a new transfer pump control as well.

Up till now water has been transferred from the exterior in-ground cistern by the old original manual pump and then by a submersible 12 VDC pump. Both required you to be outside and to monitor the level in the interior tank.

Now the inside tank gets filled automatically. The same submersible cistern pump is used but it is turned off automatically when the full level is reached. The pump also starts up again when the low level is reached.

(the cistern level indicator was previously pictured as it was being tested. It has been mounted in the cabin after I decided to run wires underground through some small conduit. Si no new photo of that part.....)

I ran wires for the transfer pump through the same underground conduit.  The control unit mounts to the wall and looks like this....



The rocker switch turns the control on and off. (lettering is superimposed on the photo, not printed on the box)

When starting from an empty inside tank both the red LED's illuminate. The one marked "P" indicates the transfer pump is running. The red LED marked "L" indicates the water level in the inside tank is Low.

As the level rises the red LED "L" goes off and the amber LED marked "M" illuminates. The "P" LED remains on with the still operating pump. The "M" LED has a broad range, from about 2 gallons to 13 gallons.

When the full level is reached the green LED "F" illuminates and the other LED's are all extinguished. That occurs at 14 about gallons.

As we draw off water and the level falls the green LED "F" extinguishes and the amber "M" LED illuminates. The "M" LED remains on until the level reaches Low.

At that point both the red LED's "L" and "P" illuminate again. The pump starts and the tank refills and the whole routine repeats.

The power draw of the control unit is minimal, at the milli-amp level, so I do not worry about leaving the controller on all day. We have been turning it off at night simply to avoid the LED light beaming across the room. When we leave all power is turned off.

Box,control board, 12 VDC to 5 VDC power supply and switch are all direct China ebay imports. Total cost was less than $15. There was a glitch as sometimes happens on these direct China imports. One of the soldered circuit board connections has a component wire bent. When it was soldered a solder bridge was formed. That prevented the relay from operating correctly. Fortunately it did not cause any component damage. However it was inconvenient. The vendor was apologetic and refunded $2 of the $4.89 control board price though. So the cost is less than $13. Not bad for a now automated system.

[MountainDon]

pump control board

The box is advertised as waterproof and would be rain resistant for sure. I bought it for the clear cover mainly.

12 to 5 vdc converter

switch was on hand from previous bulk purchase

[John Raabe]

Nice work well documented. I had no idea that equipment for projects like this was available so inexpensively. 

[MountainDon]

There is a lot of electronics equipment components like that on ebay.com  A wide variety and if one has some knowledge all it takes is patience for the slow boat from China and a little cash.

I've bought an assortment of items direct from China over the past year or so. I have had two other problems; a rate of about 15% which may be considered high I suppose. One was a similar quality assurance problem that was also resolved in a friendly manner. The third issue was one of the product details be different enough as to not meet my needs. That was also resolved in my favor but took more "back and forth" and a final threat to give them a zero stars review if they didn't make good.

The big problem with direct from China as I see it, is that most if not all sellers offers return privileges and full refund but the shipping from the USA back to China is crazy! The previous quality issue was resolved by the seller voluntarily offering to send a second for free with no return required. That was quite acceptable. It also helps to not be in a hurry as the slow boat takes 14 to 21 days.

[MountainDon]

I forgot to mention one important detail. [headslap]

The unit works by using / measuring the conductivity of water. Water has to contact these points and the very low voltage, low amperage current path is completed through the water. There are  special contacts made for RV tanks. I used a home made solution. Well nuts are rubber "sleeves" with a brass threaded fitting molded in one end.



Drill a hole, insert the well nut, tighten the screw with the wire connected under the bolt/screw head. They are squished, shortened and the rubber seals the hole. They do have a problem when using in a tank full of a fluid like water. The threads are not tight enough fitting to seal the water perfectly. A little bit of silicone sealant solves that.   They are meant for blind fitting where you can not reach behind.

If I had easy access to the top of the tank I might have used a solution like I did in the previously illustrated exterior in-ground cistern. That would have meant pulling the tank which would have included disconnecting lots of plumbing. I tried the well nuts in an old pail and was satisfied.

[rick91351]

Very impressive - however a question would it work in a metal tank?  Would the metal ground it out? 

[MountainDon]

Needs to be a plastic, non conductive tank.   

[rick91351]

Not altogether a bad thing.  Light bulb going off.   

[MountainDon]

Which are you thinking off?  The first one that just shows the level in the cistern? Or the second that controls my transfer pump? 

IF you are thinking about the transfer pump here's some thoughts.....  if the tank was metal and you used the rubber well nuts I think the rubber would insulate the sensor contact screw from the metal. For the pump controller I think that would work. That uses a total of four sensors, two high level and two low level. They are mounted in pairs.

IF you are thinking of the first, level only - no pump control, there may be hope too. That uses one contact as a common point, low in the tank. That could likely be just connected to the metal tank itself. Then mount the other three sensor contacts in rubber well nuts. They would just connect through the water same as if the tank was non conductive.

I think?

[OlJarhead]

I wonder how well this would work in a 300 gallon cistern that is 500 feet from the indicator?

[MountainDon]

   I'm not sure.  There is not much current through the sensor wires. Just off hand I don't know what the board itself draws. I could measure that but that will not happen for a few weeks right now. I'll let you know.  Hopefully something like telephone wire would work for the distance.   

[rick91351]

Which are you thinking off?  The first one that just shows the level in the cistern? Or the second that controls my transfer pump? 

IF you are thinking about the transfer pump here's some thoughts.....  if the tank was metal and you used the rubber well nuts I think the rubber would insulate the sensor contact screw from the metal. For the pump controller I think that would work. That uses a total of four sensors, two high level and two low level. They are mounted in pairs.

IF you are thinking of the first, level only - no pump control, there may be hope too. That uses one contact as a common point, low in the tank. That could likely be just connected to the metal tank itself. Then mount the other three sensor contacts in rubber well nuts. They would just connect through the water same as if the tank was non conductive.

I think?

Basically a tank switch that would trigger an irrigation pump.  I have a large (huge) tank but it is metal.  I could use a smaller poly tank.... as a trigger.  I have it as well.  It is just sitting, that or we are going to temp mount it on a fire trailer.    Still thinking....  Not the first thing on my line up right now however. 

[MountainDon]

FWIW and FYI, I have described how I use this control board. There is a switch on the board that allows the relay / pump function to be altered. It can be set to activate a pump or valve when the tank reaches full. For example a tank could be gravity filled from a spring. When the tank reaches full the pump then would come on and pump until the tank was at the low level, then shut off and wait.

[Adam Roby]

I suppose a very simple "level detector" could be made by simply using some plastic float sensors, spaced accordingly to the level of precision you are looking for.  They could be mounted to the side of the tank itself (if above ground) or perhaps mounted on a piece of plastic PVC pipe with the wires on the inside (height of the tank) and again with as many sensors as precision needed.  Then each sensor would simply be wired to an LED array, showing a basic level.  This can be activated with a manual switch so that no power is being used when not needed.  The drawing I made is simply 4 sensors, with 4 LEDs that would show full, 3/4, 1/2, 1/4, and none on would mean under 1/4 to empty.  The more sensors and LEDs the more precision.  Could use any battery (9 volt shown as an example only) just adjust the resistors in consequence.

Something like this: (I think I would prefer them being installed on a pipe and inserted rather than adding a potential leak hazard but for the sake of explanation the drawing shows directly mounted to tank)



This is the first such sensor that pop up on eBay, I am sure a more thorough search would yield even cheaper sensors, or perhaps you may need to look for ones that prefer colder weather, but this is still under $2 each so might be worth a try.

http://www.ebay.com/itm/Liquid-Water-Level-Sensor-Horizontal-Float-Switch-For-Aquariums-Fish-Tank-Pool-/311231357646

[OlJarhead]

http://www.koat.com/news/marathon-runner-injured-in-bear-attack/40126104

[MountainDon]

Maybe that's why I don't run marathons? 

That's just a few miles down the highway from our turn off. 

A young bear has been seen a few times in the Los Alamos area where we are right now. In town, but then pretty much anywhere "in town" is a short walk to the forest.   

[hpinson]

Sad ending to this story. The bear, and presumably the cub it was protecting, have been euthanized.

[hpinson]

Just heard that if the 3 cubs are found they will not be euthanized, but will go to some wildlife center.

[OlJarhead]

Good news on the cubs

[MountainDon]

Dodged another bullet, er , wildfire, by the looks of it.

The Cajete fire was started by an abandoned campfire (Grrr!!!). With the 10,000 acre thinning that is progressing and the wildfires of 2011, 2013 and 2014 there is a lot less fuel than 10 years ago. 

[hpinson]

I was wondering. We see the smoke plume, but it seemed reduced yesterday a bit. Low winds fortunately.