Sprinkler System Control

Options
System
System Posts: 2,511 admin
in Solar Beginners Corner #1
Hi,
I am one of the guys that acts first and then starts reading... not good sometimes. I came across the Harbor Freight 45W panels for $149 and I just bought one set. I also purchased a 12V Battery (Scooter - 12V 55Ah)

I have a large property and have water supply lines run to the back. Back there I have no electricity and I figured I could use the solar to run a regular sprinkler controller and sprinkler valves. Due to reduced water pressure I can not run more than three spinklers at the time and I figured I need about 9 stations (Orbit).

Now, I found out that the sprinkler controller is 24V and that the sprinkler vales are 24V. At first I thought I just use a converter to 110VAC and then the manufacturer 24VDC converter but my mechanical engineering mind says that this is too much losses. Then I started reading up on DC converters (12V to 24V) but I am not sure if this is an efficiency improvement.

Options:

1) stick with 12V battery bank - convert up to 24V with DC-DC converter, something like this

2) Use a new solar charge regulator that charges 12V but also has 24V outlet, something like this

3) Use the three solar panels in series to get 36V, buy a second battery to get to a 24V bank, I guess I need a new regulator to charge this setup. Have not found anything yet and need advise. Can I run the three in series without destroying the last panel?

4) use a 12V Sprinkler controller and valves - need suggestions!

5) any other options?

Any input or pointers are highly appreciated!
· Share on Twitter

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #2
    Options
    Re: Sprinkler System Control

    And you need to check to see if the 12/24 volt valves are AC or DC... If AC, running them on DC can allow too much current to flow.

    The home units may be DC, and the commercial versions may be AC (I don't know--just guessing).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • bsolar
    bsolar Solar Expert Posts: 103 ✭✭✭
    #3
    Options
    Re: Sprinkler System Control

    whats the amp rating on the transformer that comes with it .. to me it would make more sense to just use an inverter and be done with it ..

    .. another consideration is a 'direct' connection will probably fluctuate the voltage on your equipment and of course, i have no idea exactly how your equipment works, but it could cause some funky operation with say 14.2v sometimes and a straight 12.7 at others .. would be much more regulated i would assume, with the stock transformer on an inverter ..
    · Share on Twitter
  • System2
    System2 Posts: 6,290 admin
    #4
    Options
    Re: Sprinkler System Control
    BB. wrote: »
    And you need to check to see if the 12/24 volt valves are AC or DC.

    I checked with the providers - the valves are 24VAC. So I guess I go via a 12V inverter. I have an old UPS Backup tool that is collecting dust.
    · Share on Twitter
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #5
    Options
    Re: Sprinkler System Control

    Personallly, I would look around for commercial solar powered irrigation control systems... Don't know anything about these models or vendor, but I would go with something like them (looking around, these are scary expensive devices--probably well >$1,000 for a complete setup--hopefully you can find something less expensive).

    Getting timers/control valves designed for use with solar (very low power requirements) is much better (more reliable and much less costly) than trying to build out out a dedicated solar power system to power a normal system designed for AC power. Running a system on a salvaged UPS system is going to waste a lot of power and require a hefty solar array and battery bank to operate.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • TheBackRoads
    TheBackRoads Solar Expert Posts: 274 ✭✭
    #6
    Options
    Re: Sprinkler System Control

    I'd use what you have and just get an inverter and call it a day. Tho I'd watch your system voltage closely as that might be a hard load to accurately figure out.
    (you might need more solar)

    http://www.solar-electric.com/sa150wa12vos.html

    http://www.solar-electric.com/mosu300wasiw.html

    BB - Irritrol makes great stuff BTW.
    · Share on Twitter
  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #7
    Options
    Re: Sprinkler System Control

    TBR,

    Glad to hear that Irritrol has great products... I kind of guessed that these where the guys used around our area for remote irrigation systems (yea--I am the guy that looks inside of stuff when it is being serviced :roll:).

    Another issue to watch out for with Inverter Powered Timers--If the timers use line frequency--you may find that they are not very accurate (1% error--standard for many inverters will give you upwards of 14 minutes a day of drift in time).

    Me, I used cheap battery powered timers and valves (less than $100 for a single station). They only last a few years before needing replacement--but they do work with a 9 volt battery change once a year.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • System2
    System2 Posts: 6,290 admin
    #8
    Options
    Re: Sprinkler System Control

    I have currently 4 of the battery operated timers working but I use the water hoses for irrigation. I wanted to create something more permanent.

    I just ordered this item: 12VIrrigTimer

    I bounced some emails around with these guys - very responsive by the way - and it looks like they use existing technology and convert this to 12V and make it work with standard 24 VAC valves. They give 2 year warranty on this conversion.

    I will post results once I tested this.
    · Share on Twitter
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #9
    Options
    Re: Sprinkler System Control

    This last week, I scrapped out a year old Hunter 12V DC timer and 6 Barraca DC valves. The valves never worked right, and if any 1 stuck open, it'd drain my water tanks overnight.

    Ended up trenching 1200 feet, pulling 240VAC, installing a 240 - 24V transformer, regular timer, regular 24VAC valves.

    Been working for 2 days, but it's regular mass production stuff, and I'm more trusting of it, than the specialty stuff.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

    · Share on Twitter

Categories