How to Connect a 24V AC Solenoid Water Valve with Arduino?

Other Hardware Motors, Mechanics, Power and CNC
1

How do I trigger the 24V AC Solenoid Water Valve using my Arduino ? I already have a dual channel relay module for this project (when I did the POC with a Light Bulb with a 220 volt it worked) - But on the actual Valve I am struggling. I have attached a picture of the valve for reference. It has two cables -

  1. How do I provide the power to the Valve
  2. How do I provide the Signal for Switching
  3. How do I start the sprinkler using the valve and continue watering for 15 minutes till it stops automatically.
  4. Is there any additional Diode , Mosfet etc required for this connection using breadboard ?

Can someone please guide me with step by step direction? After reading all related articles and documents I am more confused at this stage. I am also attaching a picture of the Valve for reference
-Tushar

IMG_20180328_000024_HHT.jpg
IMG_20180328_000024_HHT.jpg1500×2000 216 KB

2

Do you have a mains voltage to 24VAC transformer with enough power (Watts) to operate the valve? Can you post a link to the valve? Looks like a motorized valve so may only need a short pulse of power to turn ON / OFF. Or post another picture showing the valve data plate (Volts, Amps, Watts).

3

The Water Valve Electrical Specification :-

24 VAC 50/60 Hz (cycles per second) solenoid power requirement:
0.30 A (7.2 VA) inrush current; 0.23 A (5.5 VA) holding current
Solenoid coil resistance: 38 Ohms

This you tube video talks about the function of the valve for reference

My Biggest challenge - as per the video - How do I replace their Irrigation System / Program monitor using my Arduino (Connection Preservative) - This has two wires as Output from the valve - One common and one for Signal - I am struggling where do I add the input of 24 VOLT in absence of the irrigation monitor.

Please extend your help.
-Tushar

4

Each valve has two wires, one of these can be commoned as in video, the other goes via the relay to the 24Vac
supply/transformer.

The relay board then interfaces to the Arduino, just like any other use of a relay board.

You'll need some snubber components across the relay contacts as the load is highly inductive, the datasheet for
the solenoid valve ought to say something about these, if its a good datasheet, as snubber components are
tuned to the load.

Alternatively as a snubber you could use a simple ~60V TVS diode, that ought to be pretty foolproof method
without needing to calculate capacitor/resistor values.