Solenoid for Ro/Di
 

Hi guys

Anyone use one of these solenoid to turn their RO/DI off and on? I just installed one of these and it makes a pretty loud buzzing noise. I was expecting it to click on with power and than click off when the power is cut....

I use solenoid valves quite a bit. It should be quiet when is on. That one in the picture is a direct action valve. It can become noisy if there is any dirt or anything that would limit the travel of the plunger. If it is a DC valve and you supply it with AC, it will be noisy and it will burn out. If it has a coil for a different voltage, it will do that (that info is printed on the coil). If you use it outside the pressure range that it was build for or if was connected backwards to the water line.

also, there should be an arrow indicating direction of flow

Ahh I see. I will look for an arrow. The valve is rated for 24 v DC. I am using a 24 v ac adapter that I got from the source. Do I have the correct one?

no, you need DC

These adapter converts ac to dc correct? If not where can I buy a dc adapter?

When you buy the power supply 115V AC to 24V DC make sure the maximum capable load of the power source is higher than what the valve takes. You might be better of just buying a 115VAC valve and replace that one.
Just a reminder, in the solenoid valves the plunger and the spring are metal (some sort of stainless-a chrome nickel alloy). The RO water is slightly acidic, so you want the valve installed on the raw water side, not on the RO side.

if the adapter is DC then it has some diodes built in, you could add a couple diodes to rectify the AC to DC.
you can get them at an electronics store, we have circuit city here in ontario, do you have a princess auto there?

Thanks for all the help guys. Yeah we have princess auto. Which diodes would I need? Also this is directly on the RO side of things. I have it setup working with a float valve in my sump. This valve is suppose to turn on for 30 min a day to aid as a backup for the float valve.

It does almost sounds like the adapter is putting put power where it makes it turn on and off really quick... Maybe this diodes is the answer?

you would need at least 2, 1 amp rectifying diodes, or a bridge rectifier, or they might have a 24v DC adapter cheap.

Omg... I found my problem.... This is what I purchased.... http://m.thesource.ca/product.php?pt...675&lang=en-CA

It's an 24v ac adapter. Were can I find dc adapter?

actually you would only one 1 amp diode to build a half wave rectifier but it might be better to build a bridge rectifier with 4 diodes

If is on the RO side move it on the other side, in front of the RO unit. You don't want to contaminate your RO water with metal ions. I don't like the idea of using a RO unit directly in a ATO system. When you start the RO unit the first 1-2 liters are not the best quality, if it produces only 50ml or less 20-50 times a day, you're not gonna get the best water.

Thanks cal. I will do some research to find out how to build that.

I sure will move the valve over to the incoming water side. Thanks for the advice. I just hope I didn't damage anything by letting it run with ac for a good 30 min already...

no, should not have damaged it, just google "bridge rectifier", the diodes will get warm so if you tape them up do it so the plastic part of the diode is exposed to the air so they doesn't overheat

Cal does this look right?

no, you have the red and black reversed, the polarity is wrong, however, the solenoid might not care about polarity but I would correct it just in case

You're much better off finding a 24 VDC adapter. All the components will be designed to the specifications the adapter is made for. Trying to piece together a full wave rectifier with loose components without knowing the specs of the adapter you're using is looking for trouble. There's generally more to a rectifier than a few diodes. Many rectifier circuits include resistors, capacitors & coils to further filter the AC signal.

Might have to look a little harder for a 24 VDC adapter but they are available. Example, the EcoTech VorTech power supplies are 24 VDC. Costly option, but I'm sure if you search around on the net, you'll find something suitable for a reasonable price.

[quote=mike31154;678937]You're much better off finding a 24 VDC adapter. All the components will be designed to the specifications the adapter is made for. Trying to piece together a full wave rectifier with loose components without knowing the specs of the adapter you're using is looking for trouble. There's generally more to a rectifier than a few diodes. Many rectifier circuits include resistors, capacitors & coils to further filter the AC signal.

The transformer he is using is rated at 1 amp, the diodes are rated at 1 amp, the coil he is powering probably draws about 1/4 amp, he has soldered his connections, other than the reverse polarity he has done a fine job.

For noise check for loose screws on the top of the unit, I have a similar one and it made a loud buzzing sound when one of the screws holding the solenoid on came loose.

Verify that the voltage is in fact 24VDC, not very typical. 24VAC is standard for sprinkler solenoid, which you can also use, rainbirds have been very reliable IME.

If you're using this for top off directly from an RO unit be sure you have enough safety built in to it so it won't be accidently left on too long or stay on from a faulty float switch or even the solenoid.

Thanks all all the help. The solenoid worked! I tested the v out and it reads around 24. The solenoid makes 1 click and than the water is flowing now! I do have one problem.... The solenoid itself gets pretty warm after 15 of running. The ac adapter and diodes does not get warm at all. Normal for the solenoid to get warm?

I will keep on searching for a 24vdc adapter around :) until then... This will do the trick!

Glad to see it worked out as a quick fix. Good idea to look for a purpose built 24 VDC adapter as well, though. Intent of my earlier post was not to critique your work, merely to recommend that an adapter more suited to the requirements would be a better long term solution. Having the rectifier exposed outside the adapter housing with no protection could be an issue. You might consider protecting it somehow.

that transformer provides total isolation from your house voltage, the 24v side is basically harmless even if you short circuit it, just don't put it in your mouth, you could tape up the wires but I would leave the plastic parts of the diodes exposed to the air, you probably did a better job on that then anything you could buy out of china.

Will do! Thanks for all the help again everyone.

Don't mean to hijack this thread but where did you find the solenoid that fits the 1/4" water line? I've been looking for a while.

I'd like to setup one because I far often leave my ro/di unit on far too long and the jugs overflow onto the ground and down the drain, wasting water.

Thanks!

I got mine at maxwaterflow.com I Order all my RoDi stuff from there.