Announcement

Collapse
No announcement yet.

Pump winding up and down.

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Pump winding up and down.

    We have a Thomsen #4 with a Leeson 1hp Washdown motor. 120v single phase. The last two weeks only during whirlpool and transfer through the HX its been winding down then back up to full speed. As if it was a VFD and you were turning it up and down. Never an issue with chemicals or transfers to the brites. We did just have to buy new hoses and went with 1 inch on the inlet hose due to cost savings.

    Any ideas?

    My thoughts were to
    1 New 1.5 inch inlet hose.
    2 New 1.5hp motor and keep the 1hp for redundancy.

    Chris

  • #2
    Your new 1" hose is not letting enough flow through the pump and you might be cavitating. Inlet should always be oversized from the outlet.

    Comment


    • #3
      I use 1 inch hose for some of my transfers through a 1.5 inch pump head. Never any problems, it just takes longer than with 1.5 inch hose.

      Cheers,

      Rich DeLano
      rich2thebrewinglair.com

      Comment


      • #4
        Originally posted by jebzter View Post
        Your new 1" hose is not letting enough flow through the pump and you might be cavitating. Inlet should always be oversized from the outlet.
        That is my first inclination especially after talking to a friend. Im getting a new short 1.5 inch inlet hose from a local dealer and we'll see if that fixes things.

        Chris

        Comment


        • #5
          Honestly sounds like your VFD is not properly configured for the pump you are using. On your VFD, you should be able to set the maximum hertz, full load amps, and voltage. It sounds like the VFD is thinking you are drawing too many amps to the pump and is winding down to save the motor. I would check your parameters. The VFD is not likely to know that the pump is cavitating unless it is drawing more amps than it believes it should be.

          Cheers,

          James

          Comment


          • #6
            Originally posted by NHBrewer23 View Post
            Honestly sounds like your VFD is not properly configured for the pump you are using. On your VFD, you should be able to set the maximum hertz, full load amps, and voltage. It sounds like the VFD is thinking you are drawing too many amps to the pump and is winding down to save the motor. I would check your parameters. The VFD is not likely to know that the pump is cavitating unless it is drawing more amps than it believes it should be.

            Cheers,

            James

            James

            Ours is Single phase with no VFD.
            Only does it under Whirlpool or Knock Out. Never during CIP or Completed beer transfer.

            Chris

            Comment


            • #7
              Originally posted by Rooh View Post
              I use 1 inch hose for some of my transfers through a 1.5 inch pump head. Never any problems, it just takes longer than with 1.5 inch hose.

              Cheers,

              Rich DeLano
              rich2thebrewinglair.com
              He stated that it only happens on whirlpool and knockout, both times the wort is near boiling, so it takes a lot less suction to cavitate since its vapor pressure is already near that of boiling. Cold transfers can be done this way with less issue because it takes a lot lower pressure to get the liquid to boil.
              Also, as the OP stated, single phase pump. No VFD on it to be failing. Either the start/run capacitor is on its way out, but I've not seen one fail like this, or the cavitations are causing the pump to go in and out of full load and the RPM go up and down with the change in load.

              Comment


              • #8
                Originally posted by jebzter View Post
                He stated that it only happens on whirlpool and knockout, both times the wort is near boiling, so it takes a lot less suction to cavitate since its vapor pressure is already near that of boiling. Cold transfers can be done this way with less issue because it takes a lot lower pressure to get the liquid to boil.
                Also, as the OP stated, single phase pump. No VFD on it to be failing. Either the start/run capacitor is on its way out, but I've not seen one fail like this, or the cavitations are causing the pump to go in and out of full load and the RPM go up and down with the change in load.

                Im going to grab a 6ft length of 1.5 inch some time this week, I think that will take care of it, I'm sparging right now w/o any issues.

                Thanks everyone.

                Chris

                Comment


                • #9
                  cavitation

                  You could try adding BF valve on the outlet to create a little back pressure. This would reduce the flow and the cavitiation, if that is what it is.

                  You will know if it is cavitating, it sounds like the pump head is full of marbles.
                  Your CPE Systems Team!
                  CPE Systems Inc.
                  800-668-2268
                  CPEsystems.com
                  Thinkpumps.com
                  sales@cpesystems.com

                  Comment


                  • #10
                    If you are going to upgrade to a 1 1/2 HP motor, get a 3 phase motor and a VFD. You will thank yourself for years to come.
                    Your CPE Systems Team!
                    CPE Systems Inc.
                    800-668-2268
                    CPEsystems.com
                    Thinkpumps.com
                    sales@cpesystems.com

                    Comment


                    • #11
                      Originally posted by CPESystems View Post
                      You could try adding BF valve on the outlet to create a little back pressure. This would reduce the flow and the cavitiation, if that is what it is.

                      You will know if it is cavitating, it sounds like the pump head is full of marbles.
                      Got one on the outlet side. When this pump motor eats it were going VFD for transfer or may keep this one as is for CIP.

                      Chris

                      Comment

                      Working...
                      X