Pump Question on townhome complex

Discussion in 'Irrigation' started by zimmatic, Jan 25, 2009.

  1. zimmatic

    zimmatic LawnSite Senior Member
    Posts: 411

    I took on a town home complex last year. 36 zones, approx 15-20 heads on a zone. PGP's almost all nozzled at 6.The system has many problems it is about 10 years old now. The last problem to happen was the booster pump failed, and it needs to be replaced this year.

    The senerio of the dog house is.
    no pump was orginaly installed when the system was installed. The main line is 55psi with a 2" line.
    The 2" line goes into a 1.5" water meter. The 1.5" water meter goes into a 2" rpz Then takes a 90 degree turn reduced down to 1.5" into the pump. (flint and walling 2hp 2 stage centrifical 120volt) The pump discharge is 1.25" then back into a 2" main line. There are some 90 degree elbows in there.
    The problem is the pump didnt want to start even though the relay was engaged and then other times it started without a problem. I figure the starter kicked in and out and finnaly became so weak that it failed. When the pump ran it was very HOT to the touch, I havent had pumps that seemed to run that hot.

    The reason I say it didnt have a booster pump is because the orginal hight of the 2" water line and the 2" irrigation main line are the same height and it looks as if the pump was an after thought due to all the odd fittings to make the pump work/fit into the confined area.

    I contacted flint and walling and they thought the pump was haveing a tough time opperating, was because the surge of water that took place in that split second from when a valve opened to when the pump turned on was making the pump work hard. Not only that but since the systems zones seem to big for the amount of water supplied there wasnt enough back force.
    Their suggestion was
    to route the water around the pump. Meaning from the rpz go directly to the irrigation mainline, with a check valve in that line. but before the check valve put a tee in line and run that to the pump, then the pump discarge would tee after the other side of the check valve. Then when the pump turned on it would build enough pressure to close the check valve and the water would flow from the rpz to the pump to the system. The pump would also run on 220v
    I know the system has many many problems but this hoa only wants to see water comming out of the sprinklers. I try in vain to have them remodel or very least have the zones re nozzled and they say no.

    I want to replace the pump with another f/w 3hp 3 stage. However, I am open to suggestions. I only want to do this one time

    I know it was a long read and may not make sense so I will try to answer the ??ns However, please offer some solid advice.
  2. mitchgo

    mitchgo LawnSite Silver Member
    Posts: 2,780

    What kind of Back flow is your rpz?

    How Old is the Booster pump ? Could it be failing due to age?
    Personally I would try one zone with reduced nozzles with out the pump to see how it handles. But if the client doesn't want that go with what he wants.
    Last edited: Jan 25, 2009
  3. EagleLandscape

    EagleLandscape LawnSite Platinum Member
    Male, from Garland, Texas
    Posts: 4,347

    If the pump is getting a surge problem, check the controller and see if you have like a Zone:Zone delay, or a Pump:Zone delay. That way the clock will turn the pump on, let it build in the line, and 5 seconds later or so the valve will turn on. That;s also a good thing with those larger pipe sizes, you have large volume of water that you need to push, better fill it up.
  4. zimmatic

    zimmatic LawnSite Senior Member
    Posts: 411

    The controllers are Irritrol total control 24 station outdoor controllers."they look orginal to the system"
    The pump start relay is a hunter PSR -22
    The RPZ is a Wilkins 975XL 2"
    The pump was 4 years old and only worked 6 months out of a year.
    There is also NOT a master valve on the system
  5. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 47,712

    You might put a master valve on the system, downstream of the pump. Then you could add a pressure tank to the pump setup, and control the booster pump by way of a pressure switch.
  6. Sprinkus

    Sprinkus LawnSite Silver Member
    Posts: 2,108

    Have you checked the check valves in the RP? I've recently had two jobs in a row where the check valves were getting hung up, which caused a restriction in the flow to the system.
    If possible I would wire the pump for 220v.
    The advice from Flint & Walling looks good, in fact I've done this on several large pumps systems before. Just make sure the check valves flow labels aren't installed wrong. (This actually happened to me with some Crispin silent check valves)
  7. zimmatic

    zimmatic LawnSite Senior Member
    Posts: 411

    The Rp was rebuilt,and tested last spring.
    Sprinkus, so that does work. Did you have the same issues I had?
  8. Sprinkus

    Sprinkus LawnSite Silver Member
    Posts: 2,108

    In my case the systems were spec'd that way, but it makes sense.

    In your case it seems to me like that pump should be putting out some serious pressure to the heads unless there is a restriction or the impellers are worn.
    Also, I've never run a 2 hp pump on 110 before and I wouldn't recommend it unless the wiring and associated circuits are beefy enough to handle it.
    Hmmm, one other thing I've rarely seen is a water meter that has broken parts in it, which caused a restriction.
    I'd still check the checks, just to eliminate that from the list of possible problems.
  9. mitchgo

    mitchgo LawnSite Silver Member
    Posts: 2,780

    The RP is taking away 7-10psi per check.. so at 55 psi being already at the start reduced down to possible 35 psi.

    Install a double check if you can if you are still have issues after the new pump
  10. zimmatic

    zimmatic LawnSite Senior Member
    Posts: 411

    I never took a pressure sample it was written on the 2" main line before the meter The psi was also confirmed from the city since they check the rpz when the meter gets reinstalled each season. 35psi would be close since when the pump isnt on the sprinklers are only 3/4 of the way up, on the closest zone to the poc
    Which ever pump I reinstall it will be wired at 220v

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