Auto Top off with high and low limits??

i wonder if joedirt found his solenoids.

with your design i wouldnt be nervous using a cheap off the shelf 110vac all plastic icemaker solenoid. of course cheap to me means free.
 
I don't like the idea of ever having an unlimited water supply hooked to my tank (you and I have talked about this before).

My goal is to make the chance of disaster a very slim reality.

In my eyes the best setup for most folks would be as follows.

1) FLOAT VALVE IN SUMP
2) HIGH LIMIT SWITCH IN SUMP (a very good idea)
3) LOW LIMIT SWITCH IN SUMP (optional)
4) 5 GAL or similar Resevoir with HIGH AND LOW latch floats.
5) TIMER (optional and could cause headaches)

The idea is to use the float valve to keep a constant water level in the sump. The 5 gal resevoir feeds the float valve. The resevoir does not start to refill until it is empty (the bottom float).

The latch circuit has a safety float in the sump in case the float valve leaks. If this happens, the sump water level will rise and open the HIGH LIMIT swith in the sump, resetting the latch. Worst case scenario, the bucket was FULL and the sump gets 5 extra gallons. Something that most sumps and salinities can handle. The resevoir will not start to refill again becuase the high limit float has removed the relay from the circuit.

Of course if you leave this long enough, evaporation could cause the circuit to reset, and dump another 5 gallons in the tank. This could be fixed with yet another latch, but at this point we have gone from automated to complicated.

The low limit switch would be in parallel to the low level switch in the resevoir and force the fill procedure to start of the in resevoir float failed.

The timer is something we will not discuss as it can make the whole shooting match more confusing at this point.

Note: you can also use wire the LOW LIMIT float to turn off the return pump until the sump is at operating depth again. This would require an additonal relay and float to form another latch.

Bean
 
The thing about having it hooked to your plumbing is if any large amount of water hits the floor your insurance will have to cover it. If it's not hooked to a water supply it would vary by policy. If it makes you feel better bean you could take two solenoids and pipe the water in series and the electrical in parallel. I could see one solenoid failing open but not two.

EDIT: May not be as elegant bean but you could accomplish your schematic using 4 float switches, one relay, and some indicator/pilot lights (both control voltage and line voltage). You probably know this but just thought I'd mention it. Personally I prefer pilot light look to LEDs (when the lights go out in mech room I can still make my way around from the glow of pilot lights :D ). will have to draw it out to verify if you're interested.

EDIT#2: Scrolled down and saw outlet for return pump, make that two relays then :D
 
Last edited:
<a href=showthread.php?s=&postid=6691715#post6691715 target=_blank>Originally posted</a> by douggiestyle
i wonder if joedirt found his solenoids.

with your design i wouldnt be nervous using a cheap off the shelf 110vac all plastic icemaker solenoid. of course cheap to me means free.
Click to expand...

Thanks for all the replies guys. And yes I did find the solenoids. The link posted previously has them for $17.

http://stcvalve.com/I-Solenoid.htm

At that price what I am going to do is buy 2 of them and put both of them in line with a 3 float system. The 3rd float will be the safety and activate the 2nd solenoid along with a small piezo buzzer in the event of a main float/valve failure.

I'm still looking over the schematics posted to see what I can use. I really want to keep it all low voltage since there is no pump that I need to power.
 
I put together a quick schematic. Its based on the one stile2 put up with out the 120v and utilizing 2 valves. Could you guys take a look at it and let me know what you think. I guess I should have paid more attention in electronics in high school:rolleyes:

I think it will work though.

53758SCHEMATIC.JPG
 
<a href=showthread.php?s=&postid=6692036#post6692036 target=_blank>Originally posted</a> by BruiseAndy
The thing about having it hooked to your plumbing is if any large amount of water hits the floor your insurance will have to cover it. If it's not hooked to a water supply it would vary by policy. If it makes you feel better bean you could take two solenoids and pipe the water in series and the electrical in parallel. I could see one solenoid failing open but not two.
Click to expand...

i felt this was a good idea also. but bean mentioned using a float valve as a backup for the ro/di line entering the sump.
was all for this at first (even hagen uses one in there auto top off kit). but when i went to implement the float i notice calcium deposits on and in the ro/di line. i use a kalk reactor in line with my auto top off. this is causing the deposits. i am sure the float switch would fail in an emergency considering my situation. am planning on the extra solenoid now. i have it, may as well use it.
 
I am not so much worried about the solenoid failing, as I am a float switch sticking.

With regards to the calcium buildup, I can see that may be an issue for some people. They do make float valves with discharge tubes that would not be as prone to buildup.

There are two ways you can use hte float valve. 1) is as the level controller with the floats in the resevoir as I mentioned above. The float valve acts as the primary level controller. 2) as the discharge point above an in-sump float setup, where the float valve acts only as an emergency shut-off.

I would consider using the scenario in (1) if it is just RO/DI being used for top-off. Again the reasons are very straightforward. A stuck float valve, or resevoir switch can not cause the sump to flood. The accident is limited to 5 gallons. A stuck solenoid is s different story, but the float valve should take care of that.

In the setup stile uses and joe is contemplting, the solenoids are backed up, but hte floats are not. The emergency float will help and should give a piece of mind. The sump water level however will fluctuate between the start and stop float. This may be a problem, or may not be a problem. Small tank volumes will have salinity swings and skimmers don't like level changes. If this is not an issue, then the setup will be fine.

Bean
 
And Yes I have a parts bin full of pilot lights. I just don't use them as much anymore because they burn out. I also have been using bi-color and tri-color leds with a transisitor to change their color depending on the circuit state.

Bean
 
weasel those designs do work, but offer no real failsafe and cause the top-off solenoid or RO/DI unit to cycle on and off every few seconds or minutes. The purpose of the OPs question and this thread is to improve upon the simple "single float" top off.

The design at floatswitches.net does offer a second float in series, but still has the short cyling problem.

Bean
 
You could use a time delay relay, but then your water level is dependent on a timer vs the rate of evaporation. RH and Temp of the tank room on any given day will dicate the evap rate. You could of course set the timer to run eveyr 10 minutes or every hour.

There are lots of ways to skin a cat...
 
Do you really want a PC controlling the water level in your tank?

My automation system was first designed to be run with a PC, I have since started work on a Uc based system. I however may just use the PC to save time. However, it will only log the action of the top-off system and have the ability to disable it remotely if I need to. It will not control the level in the tank. There are just to many things to go wrong and to many extra failsafes to consider.

Bean
 
<a href=showthread.php?s=&postid=6695305#post6695305 target=_blank>Originally posted</a> by BeanAnimal
You could use a time delay relay, but then your water level is dependent on a timer vs the rate of evaporation. RH and Temp of the tank room on any given day will dicate the evap rate. You could of course set the timer to run eveyr 10 minutes or every hour.

There are lots of ways to skin a cat...
Click to expand...

ment for your timer on the low level shut off.
 
<a href=showthread.php?s=&postid=6695329#post6695329 target=_blank>Originally posted</a> by BeanAnimal
Do you really want a PC controlling the water level in your tank?

My automation system was first designed to be run with a PC, I have since started work on a Uc based system. I however may just use the PC to save time. However, it will only log the action of the top-off system and have the ability to disable it remotely if I need to. It will not control the level in the tank. There are just to many things to go wrong and to many extra failsafes to consider.

Bean
Click to expand...

nah. not for water level. for lights, wave timer, etc..
 
Well to be honest I don't have a low level shut off. My sump would have to lose 50 gallons to expose the pump. I do have a float that latches a manual reset warning and sends a message to teh controller if the water level drops 3" below the normal op level.

Bean
 
<a href=showthread.php?s=&postid=6690892#post6690892 target=_blank>Originally posted</a> by BeanAnimal
I like the timer idea as well, except in my case the DIN mount timers I have looked at cost to much and I just cant force myself to coble a non DIN unit into my design.... Sorry I have become a snob when it comes to my not yet even close to being finished panel.
Bean
Click to expand...

i thought you wanted a timer.
 
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