Dual pump setup, endless loop

Discussion in 'Pumps and Wells' started by rhwimmers, Jul 22, 2019.

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  1. Jul 22, 2019 #1

    rhwimmers

    rhwimmers

    rhwimmers

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    I inherited this setup and I've never quite understand how/why it's setup this way.
    There are 2 pumps, one of Hardline PVC and the other goes to the ribbed tubing which seems to ALWAYS have water in it, running or not it feels full. It seems both pumps run at the same time as I feel water going through both. Recently it send to always run and you can hear it get low as it starts sucking air but then the sound changes and sounds like water is pushing out again. I have a feeling there is some kind of suction/loop thing going on. There is a gas monitor (huge PVC) attached to the sump, when disconnected it if definitely drawing air out as it's almost a vacuum- don't believe/didn't know if there was anything plugged in to the gas detection thing?

    Here's a link to the photo
     
  2. Jul 22, 2019 #2

    rhwimmers

    rhwimmers

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  3. Jul 23, 2019 #3

    Diehard

    Diehard

    Diehard

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    The 2 pumps could, of course be for the purpose of backup and/or handling a higher sump level.
    Each pump should have its own discharge check valve to prevent one pump from pumping back into the discharge of the other.
    The sump located within the sump, with the PVC discharge coming out, appears to have a check valve just above the cover.
    Is one of the 2 pumps you mention that black box on the right that appears to be connected to that ribbed tubing? That ribbed tubing would always be full of water if there's a check valve at or in the pump.
    Typical sump pump cannot pump air and push the water out of the line.

    Cover could be removed to see what's going on for pump on/off activation's.

    What's that yellow box mounted on the discharge line?

    What is the "gas monitor (huge PVC) attached to the sump"? Is it in the picture or connected to that largest PVC pipe on the left that appears to be vent?
    Is it a radon monitor?
     
  4. Jul 23, 2019 #4

    rhwimmers

    rhwimmers

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    Ah, the check valves make sense on why theres always water in the tube. I took it all apart to clean it and see what was going on. The rigged tubing is indeed a second pump that's plug was just a 2 pin molex type connector, not connected to anything. I dont even see anything where it would connect into - it doesn't have a float on it or anything, just a pump. So I dont think its been doing anything for a while.
    What i've found out is the float is just bad - pump always on. The valve still clicks when its up/down - but doesnt matter. This is a Zoeller pump - seems fairly heavy duty green - guessing its 1/2 hp looking at google pics. Looks like the valves are around $50 which seems high, no clue how old this is, cant read anything on the pump even after wire brushing what I could off.
    Thinking I should just buy a new watchdog from lowes and use it - maybe cut and cap the rigged tubing so its not in play. I have had luck with mine at my old house - any thoughts on those?
    I DO have one of those pumps that run off of water pressure, not sure I want to do something I have no exp with though, this house has flooded several times before I bought it.
    Yeah thats a radon vacuum monitor.
    The yellow box was an old watchdog controller...There were parts and pieces from at least 3 different "systems".
     
  5. Jul 23, 2019 #5

    Diehard

    Diehard

    Diehard

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    The watchdog appears to be a good system but as with everything, it has its pros and cons.

    I would look closely at the capacity of the pump system vs your specific conditions and requirements. I know his may be hard to determine. Keep in mind that although the horsepower size of a sump pump may give you similar capacity, it does vary based on the pump design. For example, a solids handling pump would be less efficient and have a lower flow vs head capacity then a screened inlet sump pump.

    Also, goes without saying, consideration must be given to power outages, relative to their frequencies and duration's vs. the duration of the battery backup.

    Handling of extended power outages would require consideration of either a generator or a water powered pump(if on city water). (Those water powered backup systems typically are required to have a separate discharge line so as to avoid cross connections concerns.)

    Out of curiosity, how far does that discharge pipe have to go and at what height, relative to the sump level, does it terminate?
     
  6. Jul 23, 2019 #6

    rhwimmers

    rhwimmers

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    It goes up 9-10' then left for about 15' then ties into the other PVC going out of the house.
    I do have a water powered one - just not sure if they are as good as what I am used to using.
    The power is rarely off, and when it is off its less than a few minutes.
     
  7. Jul 23, 2019 #7

    Diehard

    Diehard

    Diehard

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    Yes based on your typical power reliability I would likely not use it myself. If worse came to worse, you would have the ability to use it as an emergency backup using garden hoses.

    Regarding my question on the discharge piping, I was just curious as to what you would be getting for Actual gpm vs head(lift) vs what the pump rates it at. Those units are typically rated at a particular GPH at a 10 Ft. lift. That's lift should actually say head as it actually refers to a specific discharge pressure, which actually gets used up and/or lost based on the length and size of the pipe as well as the height that they must lift. Sorry if I sound confusing.
    I just wrote to the Basement Watchdog service group asking if there are performance curves available for the 1/2 HP pump. That would allow a matching of their design capacities against your actual piping to get what the actual gpm you can expect to get.
    If it comes to that I would ask your piping diameter(probably 1-1/2") and the actual height above the pump where this pipe actually free falls into your larger gravity system. That would allow me to plot what is called a system head curve and match it to the pumps performance curve.
    :rolleyes: What else does a retired plumbing engineer do in his spare time? :)
     
  8. Jul 23, 2019 #8

    rhwimmers

    rhwimmers

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    Ha! Well I greatly appreciate it!

    Since the float is bad - one of the many things I found here was a "dual float" system so I plugged the working zoeller pump (with stuck float switch) into that, and then that into the wall. There is a float attached to this.
    So I am in good shape temporarily, just need to figure out the best long term scenario.
     
  9. Jul 23, 2019 #9

    Jeff Handy

    Jeff Handy

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    Zoeller pumps are good pumps, well respected.
    But the switches have gotten iffy in the last decade or so.
    So I always buy the manual models with no switch, and install a separate switch.
    One that can be easily changed, without having to pull out the whole pump during an emergency.
    The dual float switch you bought is pbly the Watchdog piggyback type switch that I normally use. Easy to change out in a few minutes with just a hose clamp and screwdriver.
    Also, that ribbed plastic flexy hose discharge line is total garbage if it is anywhere inside the house.
    It is too thin and will eventually start pissing or rupture.
    Change that to solid pvc.
    It’s ok to use that flexy hose outside the house, just make sure it is well leveled and supported, and not under strain anywhere.
    Water also needs to fully drain by gravity if you get below freezing.
    PS you can get and install a new switch for your Zoeller but don’t bother. Pump is pbly too old.
    You should really just keep your old working Zoeller as a spare, and get a new one without a switch built in.
     
  10. Jul 23, 2019 #10

    rhwimmers

    rhwimmers

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    Yeah my plan is to cut out and cap that black flex tubing. Ill buy a new pump that has a backup pump that all attaches to 1.5" pvc - no need for dual output tubes.
    So ill wait to see what you find out on the watchdog setups from lowes - dual pump with dual float switch and a car battery. Just want to be sure its sized right per your recommendation - it hasnt rained here in a few days and theres a constant drizzle of water still
     
  11. Jul 23, 2019 #11

    Jeff Handy

    Jeff Handy

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    The “gas monitor” is likely a three or four inch pvc vent line for radon gas, which can cause lung cancer.
    The sump pit is a good way to tap into the gas that is building up under your house, from small traces of uranium in the soil.
    The suction is from an exhaust blower attached somewhere else down the line, either outside the house or in your attic.
    It pulls the radon and gets it outside.
    The danger is when radon gas builds up inside the house, you breathe it for years, and it causes mutations in your lung cells, then maybe cancer.
     
  12. Jul 26, 2019 #12

    rhwimmers

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    You hear back about the watchdog?
     
  13. Jul 26, 2019 #13

    Diehard

    Diehard

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    Yes!
    I had asked, who I guess are the manufacturers of the Basement Watchdog systems, the following:

    "Lowes shows a 1/2 HP Basement Watchdog Model # BW4000, while your site shows a Model No. BW1050. Are these basically the same units?
    Is there a performance curve available for this pump? I would like to plot the actual flow I can anticipate based on my piping conditions(My system head curve)."

    They responded:

    "Model BW4000 is a combination primary pump and battery backup system. The primary pump that comes with the BW4000 is the BW1050.

    Unfortunately, we do not have curves available for those pumps."


    So all we know is what was posted in the pumps literature.

    "Primary pump capacity 3,540 GPH at a 10 Ft. lift and 4,400 GPH at 0 Ft. lift"

    That's like 59 GPM at 10 ft (Minus the losses due to friction.)

    Actually what it boils down to is trying to make sure the capacity is at least equivalent to your existing pump. Assuming the existing pump was capable of keeping up with the inflow of water into the sump.
    I guess we don't know what the existing pump is rated for but I would hope that it would typically cycle on and off.

    Similar type pumps with should have fairly similar efficiencies and similar flow vs pressure capabilities with the same size motor.
     
  14. Jul 26, 2019 #14

    Jeff Handy

    Jeff Handy

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    Two nice features with Watchdog a/c powered pumps is they use less than half the amperage of typical pumps, so you can run two and not blow the circuit.
    Also they are skinny, so you can fit two, or add in a battery pump, pretty easily even in a narrow sump pit.
     

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