Pump cycles too much

Discussion in 'Irrigation / Sprinkler Forum' started by frentz, Mar 29, 2007.

  1. frentz

    frentz New Member

    Messages:
    6
    Location:
    N.W. Fla
    Hi - I recently had a 1.5 horse submersible well installed to use for a sprinkler system. Because of the variety and location of the stuff I need to water, I find I do not have enough flow in some of my zones to keep the pump from short cycling (i.e. it cuts on at 40 psi and only takes 10 seconds to reach the 60 psi cut-off)

    If I understand the programming on the Hunter SRC Plus controller I have, I can not program 2 zones (valves) to come on at the same time. Is it ok to connect two valves to the same zone on the controller? Or is there another way to do this?

    Thanks, Floyd
  2. Wet_Boots

    Wet_Boots Sprinkler Guy

    Messages:
    798
    Location:
    Metro NYC
    First of all, a wag of the scolding finger at the designer that couldn't match up pump and zones. Or at the homeowner, if a larger pump replaced an older one, without any thought to the consequences. The Hunter Pro-C is not designed to run multiple zones. Most timers aren't.

    There is a specialty valve known as a Cycle Stop Valve, which is something similar to a pressure regulator, and is installed in the supply line to your pressure tank. The tank won't see any pressures higher than the set point of the Cycle Stop valve. What will see higher pressures is the pipe upstream of the CSV, so you do want to be sure it's in good working order.

    I expect a CSV1.25 (60 psi model) is what would fit your application, but wait to hear more from other contributors.
  3. Bob NH

    Bob NH In the Trades

    Messages:
    3,317
    Location:
    New Hampshire
    The Hunter Pro-C is rated by the manufacturer to be capable of operating 3 solenoids simultaneously:

    http://www.hunterindustries.com/Products/Controllers/procspecs.html

    SPECIFICATIONS & FEATURES
    • Outdoor models, 120VAC transformer with internal junction box
    • Indoor model, 120VAC three prong plug-in transformer
    Station output 24VAC .56 Amps
    Transformer output 24VAC 1.0 Amps
    Capable of operating equivalent of 3 solenoids simultaneously

    You can connect 2 or 3 solenoid valves to the same output to attempt to match the capacity to the pump. If you needed more than that, it is a pretty simple solution to use a relay with a 24 VAC coil off the controller and drive as many valves as you need to from the relay.

    You should determine the gallons per minute (GPM) that your pump delivers at the minimum pressure, and at 60 and 70 psi, and the discharge capacity for each zone of your system. Then select and connect solenoid valves to your controller so the discharge capacity of the zones for each controller step falls in the range of flow rate between start and stop of your pressure switch.

    If you increase the pressure setting of the pressure switch, it will give you more range because it will reduce the pump flow when the pressure is higher. That will not have any effect on the operation at the low end.

    The top pressure should not exceed the relief valve setting (probably 75 psi) or the capability of your distribution system.

    I'm not a fan of the idea that a CSV is the answer to all of the sprinkler problems. Even if you eventually put in a CSV, the system will work better if you have first matched the system to the pump as much as possible. I would never select or install a CSV without knowing the characteristics of the pump and the flow demand of the system.
    Last edited: Mar 30, 2007
  4. Wet_Boots

    Wet_Boots Sprinkler Guy

    Messages:
    798
    Location:
    Metro NYC
    I think the question was whether more than one zone could be programmed to operate simultaneously. Hunter has that capability in the ICC controller, with an additional program D (for drip!) that can run alongside another zone on some other program. All of this without actually connecting zones together.

    The statement that it takes ten seconds for the pressure to rise from cut-in to cut-off makes me think that it probably won't be possible to adjust a pressure switch and obtain constant running. Still, with an eye on the pressure rating of tank and pipes, one could make the attempt. Without any tank rating in view, I don't want them to see much over 70 psi.

    But before any of that, the system should be reexamined to see if way-undersized zones could be physically tied together, to achieve a match with the pump. Modern rotor heads have interchangeable nozzles, and should be easy to alter for matching flows.
  5. Rancher

    Rancher Guest

    The 60 psi model would never do anything is this system, it would be regulating at the cut-off pressure, i.e. the pressure switch would probably cut off before it started regulating, you would need to go with the 50 psi model, or go with an adjustable model.

    What size is your pressure tank?

    Rancher
  6. Wet_Boots

    Wet_Boots Sprinkler Guy

    Messages:
    798
    Location:
    Metro NYC
    I didn't mention that the pressure switch would be adjusted higher, if a 60 psi CSV went in. I think in terms of the 60 psi device, so that the sprinklers flow higher, and higher flow makes for lower backpressure upstream of the CSV.

    Just think, it could all be a nearly-waterlogged standard tank that's responsible for the quick cycling. So much is yet to be known about this specific situation.
  7. Rancher

    Rancher Guest

    Right I understood what you were trying to do, that's why an adjustable model would be best, that way it could be set just below the pressure switch cut out. I tested a CSV160, it regulated at 68psi, it would not have worked in this system.

    Rancher
  8. Cookie

    Cookie .

    Messages:
    5,660
    Location:
    .
    Where the dogfight go? LOL. ;) Glad to see it is over. Out of popcorn anyways, LOL.
  9. Bob NH

    Bob NH In the Trades

    Messages:
    3,317
    Location:
    New Hampshire
    EDIT: I just noticed that the original post said the controller is the SRC Plus, but Wet-Boots described the Pro C in his first reply. I used the Pro C reference in my first reply and they are not the same controller. The Pro C has the capability of do multiple valves off one out, but the SEC Plus may not put out enough current. If you need to connect more valves than the SRC Plus will handle, then it could be possible to use the Master Valve output on the low-flow circuits, or use a 24 Volt relay to turn on as many valves as are required.

    INITIAL REPLY:
    Connecting the controller to open 2 or 3 valves at the same time does physically tie those zones together. It is a lot easier to connect 2 or 3 wires to the same terminal at the controller than it is to dig up the pipes and make new plumbing connections at the valve manifold, and it has the same effect.

    It is also a lot easier to try different connections and change it back if you don't like the result.

    One thing that often limits the matching is that some low-flow zones need much longer run times than the large sprinkler zones. That can be solved by turning on the low-flow zone simultaneously with several other zones.

    Even if the controller doesn't have a drip-zone output, you can have the low-flow zone on whenever the pump is running. Another way is to use small 24 VAC relays to operate the low-flow zone with several other valves during the irrigation cycle.

    Changing the nozzles is also a good approach if the coverage can be achieved.

    By changing nozzles and connecting zones by operation of 2 or 3 valves at the same time, it should be possible to match the system to the pump.
    Last edited: Mar 30, 2007
  10. frentz

    frentz New Member

    Messages:
    6
    Location:
    N.W. Fla
    Thanks for all the replies. I quess the scolding finger will have to be waved at me as I am the designer (amateur) and builder.

    I have over 1 acre of lawn that I am watering so the big pump is nice to have for that portion. My problem is, my wife has two flower beds (roses) on opposite ends of the house that (due to the sandy soil and high summer temperatures in Florida) require more frequent watering that the lawn does. I am using bubblers in these beds. When I was laying pipe, I did not realize I could not operate two zones at once so the two beds are not connected. With only one of these zones operating - the pump short cycles.

    The specs for the SRC+ controller states that the station output is 300mA as opposed to the PRO controller which is 560mA. The specs for my valves state that they draw 190mA - based on that, it does not appear advisable for me to connect two solenoids to one output on the SRC controller.

    Looks like I will need to install a relay as Bob NH mentioned (or dig some more ;)

    Oh - my pressure tank is a FloTech 40 gallon equivilant.
  11. Rancher

    Rancher Guest

    We only do the dog fight stuff in that "other" fourm, we're all hugs and kisses here.

    Rancher
  12. Wet_Boots

    Wet_Boots Sprinkler Guy

    Messages:
    798
    Location:
    Metro NYC
    My reading of the CSV specs make me lean towards the fixed-pressure plastic ones, because they don't have so high of a minimum pressure loss. That may just be me, trying to use all of the pump output to make the sprinklers run. In fact, with most tanks being installed (not sure about those glass-lined ones) having 100 psi ratings, I could see some use for a 70 psi fixed-pressure CSV, especially when an RPZ is feeding the sprinkler system, and subtracting 15 psi.
    Maybe Google has it archived. So much for my attempt to be a force for moderation.
  13. Rancher

    Rancher Guest

    Frentz,

    We need to know the model of your 1.5 HP pump, and the depth it's set at.

    The CSV1 has a max pressure of 150psi, that pump probably exceeds that, depending on it's depth.

    Rancher
  14. frentz

    frentz New Member

    Messages:
    6
    Location:
    N.W. Fla
    My pump is a Red Hat Enduro 150F31125S10. Well is 105 ft. deep, static water level is 65 ft. below grade. 1.25" pipe from pump to pressure tank.
  15. Wet_Boots

    Wet_Boots Sprinkler Guy

    Messages:
    798
    Location:
    Metro NYC
    It is possible to run more than one valve from a SRC, (my bad on typing 'Pro-C' in an earlier post - although they both don't allow multiple zones to run at once) but it's a your-mileage-may-vary situation. The built-in overload protection will protect the clock in any event. There are even some low-current solenoids available to retrofit some valves (Irritrol) ~ although they may be hard to get.

    If it's just the rosebed zones that are doing the cycling, then try to rework them. As for bubblers, look around for alternatives to standard bubblers. Or just double (or triple) the amount of standard bubblers. All it has to do is work.
  16. Rancher

    Rancher Guest

    Red Hat, Red Jacket... what's the difference, you probably can't pump much with LINUX. You have a good pump, 3-wire Franklin motor with the 25S10 pump body, about 20 gpm from 80' at 60 psi, I couldn't find the pumps cutoff point but it looks like it would exceed the pressure limit of the plastic CSV.

    Rancher
  17. frentz

    frentz New Member

    Messages:
    6
    Location:
    N.W. Fla
    Ah - that's what my problem is - wrong operating system :D :D :D
  18. Bob NH

    Bob NH In the Trades

    Messages:
    3,317
    Location:
    New Hampshire
    I think you will notice that nobody is calling someone else a stupid idiot, or some other insulting variation of that theme. As long as everyone is talking about GPM and PSI there is no problem.

    The popularity of duels waned when Aaron Burr killed Alexander Hamilton, but if someone pokes a verbal stick in your eye it is human nature to respond.

    Maybe there should be a penalty box for personal insults: 10 days for the first offense, 30 days for the second, and banned for life for the third.
    Last edited: Mar 30, 2007
  19. Rancher

    Rancher Guest

    Terry, I think BobNH has a good, idea but how about maybe a time period, like 1 violation in a week is the suspension, 4 weeks without a violation and that cleans your record back to zero.. That way I could insult a salesman only once a month or so... :D


    Rancher
  20. Cookie

    Cookie .

    Messages:
    5,660
    Location:
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    It was a joke people lighten up. Rancher, that is funny. I know I can feel the same way about a few at work, lol. Just in case, going to buy some popcorn tonite, LOL.
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