Voltage question regarding Richdel R711A

[KineticoUser]

This control valve is rated for 24V. My original power transformer burnt out. I have two others to choose from. I used a 16VAC which measures at 17.25VAC, and everything worked fine for about a year. Now, I find it apparently doesn't open the valve enough to allow the water to reach the higher emitters. I can switch this to a 24VAC which measures at 29.25VAC, but I fear that will exceed the 24V this controller is rated for. Is this a power issue or a diaphragm issue or something else? If I open the vacuum breaker, I get plenty of pressure to reach the higher emitters. I'd like to understand the mechanics of this... not just hear recommendations without the education. What are your thoughts on this?

 

[Reach4]

Normally when you say 24 volts AC, it means that it is 24 volts plus or minus some percent. That percent could be 10 percent. It could be a little wider.

 

[Sponsor]

 

[KineticoUser]

I can understand 10%, but this is over 20%. This is just electromagnet actuated, so I don't believe the extra voltage would do harm, but I wanted to hear from the experts. I don't want to do one thing and then find out it is actually a different problem. I'd love to learn how to diagnose this problem.

 

[KineticoUser]

I switched transformers, and nothing has changed. I checked my 10K gallon tank level [gravity feed], and it is just over 1/2 full [drought conditions in Southern California]. Since I get water to the emitters when I break the vacuum, are we talking about a diaphragm issue, or could it be another problem?

 

[WorthFlorida]

Most 24v ac transformers will read up to 29v with no load. With a load it can drop to 18-24v's and a lot of it has to do with the input voltages that can be 110v to 125v ac.

....when I break the vacuum, are we talking about a diaphragm issue, or could it be another problem?

I honestly do not understand the this statement. I'm assuming your using a standard irrigation valve and the water is feed via a storage tank at a high elevation. As you stated, it could be the diaphragm. It maybe fill with crud and the small orifices may be jammed up with debris. Look at this video and you'll see how it works. Maybe removing the solenoid and flush it out maybe enough to get it working proper.

 

[KineticoUser]

The vacuum breaker is the screw on the top left of your video picture. When I open it, water flows to my upper emitters, but not when it is electrically activated. Then it only feeds the lower emitters. I'll open the controller tomorrow and see if there is any debris in the diaphragm or electromagnet switch. If there is something else you don't understand, please clarify your confusion.

 

[WorthFlorida]

I believe you mean the bleed screw. This site perhaps has your answer. It is well written with pics so I'll only reference it. At first just remove the solenoid, there may be debris in the port. The solenoid plunger barely moves and when testing it you may just feel a click. Most valves by turning the solenoid a 1/4 turn counter clockwise (loosening it) will activate the valve. The bleed screw also does the same.

https://www.irrigationtutorials.com/how-to-fix-a-automatic-irrigation-valve-that-wont-open/

 

[KineticoUser]

I cleaned everything, but nothing has changed. The insulation on the wires leading to the solenoid are cracked to the wires, so I'll exchange the solenoid next. Unfortunately, I'm too busy to spend much time on this project. It may take me a month before I can get to it, but I'll report back when I do the next step

 

[WorthFlorida]

It sure can get frustrating since a lot of it is underground. Controllers will error out if a zone has a short but not opens or high resistance. Maybe a varmint chewed on the wires. An easy thing to do is move the wire at the controller for this valve to a different zone. Sometimes the output for one zone goes bad and there is little or no voltage or with your voltmeter check the voltage with the wire connected and without the wire connected. Easy enough to do standing on your feet and should point in which direction the problem is.

I’ve had Hunter commercial controllers go bad because the printed circuit board traces burned but with smaller residential controllers usually the modules will go bad.
Good luck.

 

[HenryAquatic]

Thanks, WorthFlorida! Definitely learning a lot from this thread.

 

[hj]

IF the transformer "operates the solenoid" the valve uses the water pressure to open the valve. The solenoid merely "bleeds/drains water" from the top of the diaphragm. The valve will NOT open fully if there is a leak through the diaphragm into the upper chamber or the water passage through the bleed passage is obstructed.