RODI Auto shut off with a timer

[shibumi]

Does anybody have an idea how to make an auto shut off for a RODI system using a timer?

Thanks

[Cohiba]

You can possibly use an automated garden sprinkler timer. It's cheap (around $15) and easily found at Home Depot or Lowes.

[BeanAnimal]

What exactly are you trying to do?

[shibumi]

I am trying to use a timer to shut off the production of water. I have heard to many stories where the floating system fails and the house get flooded.

I want to set it up for 45 min and after that the system will shut off automatically.

Does it sound reasonable?

[BeanAnimal]

You will need a 120V solenoid valve from McMaster.com (or similar). You want a normally CLOSED type. Get TWO. Place them in series IN FRONT of the RO/DI unit (at the input). Hook them to the timer.

The solenoids will open and allow the unit to work when the timer is ON. They will close when the timer is off.

An alternative would be to use low voltage DC solenoids at the OUTPUT. The power supply for the solenoids would be plugged into the timer.

You could use the AC versions on the output side, but they have copper shading coils in them. That may or may not be an issue. Plenty of people use them like that, I just wouldn't.

If you need help chosing a solenoid valve let us know.

[shibumi]

I need help choosing the solenoid. And where can I get the timer?

[shibumi]

Something like a Brass Versa-Mount Solenoid Valve?

[BeanAnimal]

McMaster.com Part numbers:

A few to look at.

5077T11 (or anything from that series)
7877K5
7877K2
5489T61

[shibumi]

Awesome thanks I will look into it.

[MeuserReef]

Originally posted by shibumi
I need help choosing the solenoid. And where can I get the timer?

I got mine from http://www.mcmaster.com/

I cant remember the part number of the exact one that I bought but I did a quick search and found one that looks similar. Search for part number 7877K5


You can get a timer at Lowes or Home Depot

[MeuserReef]

Dang Bean.... your quick!

[BeanAnimal]

It is easy when you have the world at your fingertips... There is not much I can't find when I look for it.

[MeuserReef]

OK... since bordom has its hold on me... I drew a schematic of how I top my tank off.

The system includes the following:

- $5 Intermatic Timer (Lowes)
- 12V DPDT Relay (Radio Shack)
- (2) 12V Float Switches (aquahub.com)
- (2) 120V Soleniods (mcmaster.com)
- RO/DI unit (eBay)



Heres the gist of it:

The timer turns on for 15 minutes once per 24-hours. This sends 120V to the Auto Top Off Relay. Since there has been 24 hours of evaporation, the 12V float switches tell the relay to send the 120V to the solenoids. Since the solenoids are both "normally closed", the power opens them. These solenoids are on the supply line going to the RO unit. This turns the RO unit on and begins to fill my sump back up with fresh water. When the desired water level is achieved, the float switches tell the relay to stop sending power to the solenoids, closing them, therefore cutting the water supply to the RO unit. The timer governs the frequency and duration that the ATO receives power so that the RO unit isn't cycled on and off all day long. The tank gets one fill-up a day! No more, no less

This system has been setup for over a year now and works as designed! No more manual top-offs!

I will add that even with the redundancy that this setup has... I still feel the urge to knock on wood. LOL

[grochmal]

I used two 24VAC valves connected to a cheap sprinkler system timer.
The timer is great because it allows me to specify exactly when to open the valve and for how long.

http://cgi.ebay.com/ws/eBayISAPI.dll...m=140135493623

[ozfish]

I have done what your trying to do using a $40 hose timer from the local hardware store. I ran my tank with it for 4 years with no problems. Just have to remember to change the batteries on a regular basis.
I had it settup to open for one hour in the morning and one hour in the evening. Keep in mind this was a 200 gallon system.
At one stage my float valve snapped and I controlled the level in the sump purely with the timer. It worked exceptionally well and even testing every 15 minutes for 6 hours with a refractometer the SG never changed.
One other thing, ensure your RO/DI unit is fitted with an auto shut-off valve.
HTH

[cannarella]

Go to an appliance repair place and have them give you a fill valve off of a dishwasher or washing machine that is broke. You can probably get it for free. Then all you have to do it get some adapters and put it in a box. I did this one for about $20 and an hours worth of work. It all depends if you like to do DIY. I was bored and just wanted to make something.

http://s161.photobucket.com/albums/t...RO-DI_0001.flv

[shibumi]

WOW you guys are awesome .... Thanks for the help