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Sprinkler Valve Solenoids are AC?

Posted: Sat May 22, 2010 5:29 pm
by BeaverRat
I read on the solinoid that it is for AC 24 volts. How do you get this to work portable on DC voltage?
Thanks

Posted: Sat May 22, 2010 6:57 pm
by Hubb
It works DC as well.

Posted: Sat May 22, 2010 11:14 pm
by Technician1002
On a note on the DC operation, it will work on lower voltage on DC than it will on AC. The level of magnetism is related to the current in the coil. Due to inductance and resistance on AC, the current is limited. On DC only resistance limits the current, which is why the current is higher at 18 VDC than it is at 24 VAC. 2 9 volt batteries in series works fine.

Many gas appliances are rated for either 24VAC or 12VDC so they work on either AC mains or DC vehicle battery. RV refrigerators and furnaces are commonly configured this way. Most sprinkler valves work fine on 12 volts DC.

If you try to run a sprinkler system on 24 VDC, due to the time the coil remains on, the additional current will overheat the coil and ruin it. (smoke). For momentary use such a pushbutton fire control, 24 or even 27 VDC won't hurt them. 12-18 is recommended.

Posted: Sun May 23, 2010 2:44 am
by BeaverRat
Thanks,
Just tried it with a 12 volt battery and it worked fine.

Quick question though - On the sprinkler valve there is a manual release swith by the solenoid. I have used this switch a lot, but was wondering if I would gain power by using the actual solenoid over the manual switch...

Thanks

Posted: Mon May 24, 2010 2:58 pm
by Hubb
All the manual switch does is open the solenoid. And it does it rather slow. So, yeah, there will be more power from using the solenoid as intended. But the real magic with this valve is by modifying it. Check the Hubb Library for one of the most comprehensive pdf files on this valve.

Posted: Mon May 24, 2010 6:50 pm
by BeaverRat
How big of a noticible difference is there by adding a blowbun pilot valve?

Posted: Mon May 24, 2010 7:00 pm
by Gun Freak
Four times better I believe, accoriding to the Hubb library... GO READ IT!

Posted: Mon May 24, 2010 7:06 pm
by Technician1002
Hubb's thread on sprinkler valve mods is a sticky. It is this thread,
http://www.spudfiles.com/forums/the-spr ... 16786.html In there is a link to the most excellent PDF file. The file is here;
http://www.mediafire.com/?mnjm2zngvzw

This is well worth downloading and studying.

Just a note on the manual valve, it opens a bypass port that does the same thing as the solenoid, but the lever does not actually open the electric solenoid port. The port is small, so it is slow as others have mentioned.

@ hubb, you may wish to include in the wiring section the theory why a 24 VAC valve works fine on 12-18 volts DC. There is no reason to feed them 27 volts DC.