Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 10 of 10

Thread: Flow sensor that will work for the slower flow

  1. Back To Top    #1

    Flow sensor that will work for the slower flow

    Hi All,

    I recently bought a new pool pump - Hayward Super Pump Dual Speed Power Saver - that will switch between 220v and 110v.

    Unfortunately, at 110v, the flow is not sufficient to allow the flow sensor to register it.

    Anyone know if Harwil sells a flow sensor that will work for the slower flow generated by 110v pumping ?

    dan

  2. Back To Top    #2
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Flow sensor that will work for the slower flow

    Welcome to TFP!

    If the flow switch is part of a SWG you don't want to switch the flow sensor for one that will trigger at a lower flow rate. The flow switch is there to protect the SWG from causing damage when there isn't enough flow. Disabling it will probably damage the SWG and could possibly cause an explosion.

    There are single speed pumps that can be wired for either 120 volts or 240 volts, and there are dual speed pumps which run at high speed or low speed while staying at a single voltage.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  3. Back To Top    #3

    Re: Flow sensor that will work for the slower flow

    Hi Jason, thanks.

    Yes, I don't want to disable the flow sensor, I just want it to register flow when a smaller volume of water is moving past it. I am unable to use the 110v setting on my pump - which should result in significant savings in electricity use - because the sensor is reporting "No Flow" at the 110v pump setting.

    dan

  4. Back To Top    #4
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Flow sensor that will work for the slower flow

    You do not want to run the SWG at a flow rate lower than the minimum rate it is designed to run at, which, if everything is working correctly, is the same one the flow sensor is designed to switch on at. Changing the flow sensor in the way you describe will very likely damage the SWG and could (if you are a little unlucky) result in as explosion, as I said before.

    Have you tried cleaning/backwashing the filter, cleaning the skimmer basket and pump strainer basket, and seeing if that improves the flow rate enough that the SWG will turn on at low speed?
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  5. Back To Top    #5

    Re: Flow sensor that will work for the slower flow

    Yes, cleaning/backwashing the filter, cleaning the skimmer basket and pump strainer basket does not change the "No Flow" reading when the pump is set to 110v.

    dan

  6. Back To Top    #6

    Re: Flow sensor that will work for the slower flow

    I think that the two-speed SuperPump is only 230 volts. I don't think that there is a 115 volt model. I think that you're confusing hi-speed and low-speed with voltage.

    Either way, it's possible that the pump won't generate enough flow on low speed to satisfy the flow sensor.

    What is giving you the "No-Flow" error message (make and model)?

    What model is the Superpump (Model Number)?

    What is the filter pressure on low speed?

  7. Back To Top    #7

    Re: Flow sensor that will work for the slower flow

    Yes, I think you're correct that I may be confusing hi-speed/low-speed with 220v/110v. The pump is a Hayward SP2607X102S. And it is a 230v pump, per the data plate on it. (Although I think that the way the pump achieves low-speed is by using only a single leg - 115v - of the 230v power wired into it. But that's mostly academic to this discussion.)

    The "No Flow" message is a light illuminated on a Mineral Springs MS-10 unit. The salt generator is a Aqua Rite Turbo Cell T-Cell 15.

    Filter pressure at low speed is 8.5 psi. Filter pressure at high speed is 22 psi.

    dan

  8. Back To Top    #8

    Re: Flow sensor that will work for the slower flow

    The pump uses 230 volts for high speed and for low speed. However, as you've said, that is not particularly relevant. I just wanted to eliminate that as a potential issue.

    The 8.5 psi filter pressure on low speed indicates a problem somewhere. At that pressure, you will get almost no flow. Technically, it is more pressure than the pump is supposed to produce. The pressure should be less than 4 psi.

    You might have a bad pressure gauge. Does the gauge go to zero when the pump is off? You could try a new gauge to be sure.

    There could be some sort of blockage in the system somewhere. You could check the cell to make sure that it is clean. Also, you should check anything else that might be blocking the flow of water.

    If your pH, TA and Calcium Hardness are too high then you might be getting scaling in the system components.

    It's possible that even with a clean system that that pump is not going to create enough flow rate to satisfy the salt system. You might need to operate the pump on high for the amount of time needed to run the salt system.

    The flow switch (Hayward model # GLX-FLO-RP, Harwil model # Q-12DS-C2) should trigger at 10 to 15 gpm, which the pump should be able to do unless there is a problem with the system or system design.

    http://www.marquisepools.com/equipment/ ... _specs.pdf

    http://www.harwil.com/products/pool-spa/model-q-12ds

  9. Back To Top    #9

    Re: Flow sensor that will work for the slower flow

    Thanks for the thought out response James.

    When the pump is off, the pressure gauge - attached to the sand filter - reads 3psi. So it appears to be working, although not zero'ed properly.

    I took the cell off and hosed it down. There was some calcium in it (in fact more than I had ever seen - 80 or 100 finger nail sized flakes). I also emptied both strainer baskets, which were almost empty already. Turned the pump on at low speed and it still registers 8.5 psi.

    The only other thing I can think of that might be restricting the flow is my sand filter - a Sta-Rite T-240BP-1. The sand in it has never been changed and is about 8 years old. There is a tag on the filter that reads 18 psi - I think this was the original psi reading when the filter was new.

    I wonder if I replacing the sand would do any good...

  10. Back To Top    #10

    Re: Flow sensor that will work for the slower flow

    I would start by changing the pressure gauge. It is defective, and not reliable. I think that you're going to have to get the pressure below 4 psi for the flow switch to trigger. 8.5 - 3 = 5.5 psi, so we're pretty close. You might need to get the pressure as low as 2.5 psi, depending on the suction plumbing. If you have some sort of blockage on the suction side, that would reduce the flow rate. You could add a vacuum gauge to the suction side to evaluate the suction side plumbing for resistance.

    The sand might be an issue. The sand might need to be changed. If you have a multiport, you can put it on recirculate to bypass the filer to see what happens. Based on the scaling in the cell, scaling in the sand filter is quite possible. What are all of your chemical readings?

    If you change the sand, you should inspect the laterals for scaling or other obstructions.

    There could be an issue with the flow switch, but I think that the pressure should be verified first. You could pull the flow switch for closer inspection.

    You could install a flowmeter, but they're not very reliable at lower flow rates.

    What kind of flow are you getting on low speed? Is there good pressure at the returns? Is there good action in the skimmers?

    What plumbing do you have from the skimmer to the pump, and from the pump to the pool? Length, pipe diameter and restrictions, such as directional eyeballs.

    http://www.bluwhite.com/Products/Variab ... ctpage.asp

    http://www.hayward-pool.com/pdf/literat ... mp10_4.pdf

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •