Submersible Well Pump Cycles per Day

Discussion in 'Open Loop' started by glenski_31, Nov 28, 2012.

  1. glenski_31

    glenski_31 New Member

    Hi All:

    I know that there are debates about open loop on a shared domestic well, however this is what I have for now and I don't want to get into cycle stop valves etc at this point. I would just like to know if there is a number out there for maximum well pump cycles per day before you run into problems? Manufacturer literature would be nice but at the very least some experienced input. Right now I am running an ecobee tstat so am able to tell for how many seconds my HP runs on an average day and I have timed the full well pump cycle from cut off to cut in to cut off so from this I have an idea of how many cycles per day. My plan is to run what I have in my well until it and have a new pump on standby for that day.

    Right now to the best of my knowledge I have a 1/2 hp 4" submersible, which according to the driller is likely a 'Duro'.

    Unless of course I come into a bunch of unexpected money or figure out some other genius way of doing things for free.

  2. ryan5024

    ryan5024 New Member

    The Franklin Submersible Motor (largest submersible motor manufacturer in U.S.) Manual states that, "up to .75 hp single phase 300 starts per day". I'm not familiar with "duro" but I would guess that they would fall in the same catagory. It is possible/likely that Duro makes the pump end and uses a Franklin motor to power it.
  3. Calladrilling

    Calladrilling Member Industry Professional Forum Leader

    I would say go with a grundfos SQE line of submersible pumps. They are my personal favorite pumps, but come with the price tag to match too. They are variable speed motors, and built out of full stainless steel.

    I would say 300 starts/day is very high and you could not expect to have many years of life from your pump at that start rate.
    The storage tank in a geothermal open loop system is very critical when constant speed motors are used to supply your heat pump. This will eliminate starts of the submersible pump, in turn extending its life.
  4. ryan5024

    ryan5024 New Member

    Hi Dan,

    I was just quoting the manual. I would agree with you that the SQE is a good way to go, but I was under the impression the customer had an existing pump. I would run that one until it failed and the replace it with the SQE. Glen, I would never suggest a cycle stop valve, I am not a fan.
  5. glenski_31

    glenski_31 New Member

    Thanks Guys,

    I am of the same mindset, I am an engineer by trade and obsessive by nature and racked my brain for a long time trying to figure out the benefits of the cycle stop valve and it isn't clear to me and if I can't fully understand it then I don't want it installed.

    I like the idea of the SQEs as well, and certainly won't be replacing the one that I have until it burns out. My plan is to run it till there is nothing left.

    Thanks for the heads up on the Franklin motors at 300 starts per 24 hours. I am running an Ecobee Tstat right now and am loving it. There may be better systems but it works for what I want. I am able to download my heating run time down to 5 minute intervals and how many seconds it ran in those 5 mins. I got out my stop watch and am running about 230 second from pump off to on to off again at 5gpm, so when I do the math right now I am looking at approx 150 starts per day for the HP. There will be some in there for the domestic use too but it looks like for now I am going to be OK as I am half of the max. This will increase as temps drop up here in New Brunswick but I will monitor.

    I has originally intended on putting two pressure tanks in and if it becomes a problem I may but for now I am going to run it.

    Thanks again to you all.
  6. Calladrilling

    Calladrilling Member Industry Professional Forum Leader

    A cycle stop valve does nothing more than back pressure the pump on the inlet side of the tank to restrict inlet flow to match outlet at any given time during water usage. I have seen the, work flawlessly when installed correctly and set correctly, but no means are they a replacement for a SQE!
  7. awp4412

    awp4412 New Member

    Your best bet to decrease the amount of cycles that your well pump runs through during a day, with out switching to constant pressure, would be to adjust the pressure switch to allow for more pressure fluctuation between start times. Keep in mind you would need to know the minimum and maximum pressure needed for your furnace.
  8. ldameron

    ldameron New Member

    I have had a cycle stop valve for about 5 years on my open loop system and have been very satisfied with the setup. the only problem, I have is when both up and down systems are on, I don't have much domestic water pressure.
  9. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Your loss of domestic pressure is a function of pump capacity being exceeded, not the csv.
  10. ldameron

    ldameron New Member

    could i put another pump on the domestic side to boost presure?
  11. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Are you lacking flow capacity or pressure, or both. If your lack of pressure was created due to the pump being at capacity for pressure and gallons, boosting nothing = nothing, you may get increased pressure but will still only have what gpm is left. A simple note about pump curves, if you are running your pump at beyond its max capacity " you are running it off the curve " failure is immenant.
  12. llaforest

    llaforest Member

    I am in the same situation... 4 ton geo on a 15gpm@50psi single speed submersible pump... We have a 90 gal pressure thank but I fear the pump will have a lot of cycles every day. I'm not sure I want to wait until it breaks since I will be without heating for many days...

    Our plan is to add to more machines... So 4 ton with me, 3 ton for my father and another 3 ton for a chalet we rent... A total of 10 ton, possibly working all at the same time would give me a 25 gpm requirement... Should I stay with SQE or get another serie?
  13. Calladrilling

    Calladrilling Member Industry Professional Forum Leader

    If this is a supply well for domestic water and open loop supply well too then you may be beyond a SQE for a 10 ton system.
    You need well depth diameter, depth, static water level, pumping water level, and supply line size from well to house.
    Then find out your maximum volume of water needed for domestic + geo GPM needed too.
    Your more than likely outside of the SQE 1.5 hp range.
  14. llaforest

    llaforest Member

    Thanks Dan,

    This is what I thought too. Then the same company has a SmartFlo SP/CU331SP. I can't find many information on this but it outputs 3 phase signal, and goes from 2 to 5 hp. They say light commercial application and it looks good to me. Do you know where I can find information on this? Should I call Grundfos Canada?

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