DIY Auto-Top off with Solenoid

[stugray]

Sorry if I didnt read the whole thread...

Any mention of the optical liquid level sensors coupled with a Square-D Programmable Logic Controller?

I have two of the sensors & the PLC working together. I just havent tried it with SW yet.

I can easily program the PLC to turn on/off pumps based on the state of the LL-sensors.

The sensors look just like these:

http://www.fluidswitch.com/pages/OpticalLiquidLevelSensorOS-900.htm

I just need to encapsulate the sensors into a tube or shield because they are sensitive to stray light & salt creep.

Stu

 

[BeanAnimal]

I have pondered the use of those several times, but in the end did not want to deal with the salt creep or slime coat (or the price). Good old mechanical reed floats are my choice.

 

[douggiestyle]

i read a thread here where someone used optical sensors and had the problems bean described salt creep. also was some other problem, i cant remember.

 

[eleben]

I have been using the Tunze Osmolator without any problems (over a year and a half now). As you may already know, Tunze relies on the optical sensor and uses a regular vertical float sensor in case the top off pump doesn't shut off. I've checked for salt creep and haven't had any problems with it. I check for slime every once in a while and find some collecting on there but the accuracy of the sensor hasn't changed because this.

 

[H20ENG]

Bean,
I believe it was World Magnetics. The real sensitive switches are about 4" dia but you could use them to topoff a tank without a sump. They are hair trigger sensitive.
Several companies make spa air switches, but its hard to get any specs on them. They just give you a part # for a such and such controller.
I guess I COULD bite the bullet and pay retail for some....

 

[BeanAnimal]

Almost all the spa parts and equipment companies are now owned by 2 major corporations. Nobody in any part of the chain knows or understand any part of their product lines. Take a look at "Spa Builders" or "Spa Builders Support Group". They have snatched up every major spa-pack and parts OEM on the planet.

I never did order the world magnetics smaller switches (I thought I had a small one speced out that would work for our needs).

 

[thereefgeek]

What exactly was the problem with the MPL switches from Herbach? They look exactly like the MPL 600 series (don't know the exact Pt#) switches I picked up from HSC Electronics in Sac.
Supposedly they're all user-adjustable:
http://www.pressureswitch.com/products600.html
http://www.pressureswitch.com/dimensions/prod_dimensions600.html

 

[H20ENG]

They were 0.5psi, not Inches of Water, and there was no adjustment screw to remove. A nice little switch, but the wrong model # for us

 

[thereefgeek]

Oooooooooh.
0.5 psi is nearly 14" of water!! (0.433psi/foot of head pressure)

Here's a conversion table I found on MPL's website:
http://www.pressureswitch.com/reference_pressureunitconversions.html

 

[guzz64]

auto top off

auto top off

I use the parts from Mcmaster and it works well. I use two floats and two solenoids. I have the floats about 1/4" different elevations mounted on a hangon plexiglass holder I made. Both floats are set to remove power from the relay on a water rise to close the solenoid valves. I put back to back solenoid valves as I had the misfortune of the single sticking on two seperate occaisions. The floats are tied in to a time delay relay that waits 1 hour after the float signals for water. This eliminated the on/off due to waves. In my system it adds water every hour and everything seems good. I run it through my kalk reactor and life has been good since the addition of the second solenoid valve. I am going to add one more float and solenoid about 1" higher than the level I maintain in the sump as a fail safe (hopefully) to stop the whole system in case of tragedy.

 

[Old Yeller Tang]

Almost 5 yrs now and still fool-proof. How's everyone else's fared?

 

[Lunchbucket]

NEVER had a problem w/ mine!

Lunchbucket

 

[Steven M]

I still love mine, got all new parts last year just in case. Still looked like new inside.
Steve

 

[Old Yeller Tang]

Yep, I had bought a 2nd solenoid as a backup and it's still in the box just in case.

 

[coralfragger101]

Just read the first page. Can this be right?

Use a 3/4" forstner drill bit to drill a hole.
Then tap it with a 1/2" tap?

I've never tapped anything before but it seems to me that the tap would simply slip through a 3/4" hole.

 

[H20ENG]

I dont have my drill / tap chart in front of me, but yes your hole will be much larger. Remember that the 1/2" is the I.D of the pipe. So your fitting will be 1/2" I.D. and maybe 3/4" O.D., thus the larger threads.

These are pipe thread taps, as opposed to screw thread taps, so they are much larger.

HTH,
Chris

 

[coralfragger101]

Ah - Makes sense. Thanks

 

[andyman]

so hows everyones setup going? I am just about to make this thing exactly to specs and will have solenoid on timer. I'll get a different solenoid later after this one fails. So has anyones mcmaster solenoid fail? And also have anyone noticed any effects of running the solenoid on the output side of the RO/DI yet?