13 Comments


  1. I didn’t realize that three phase power configurations on well pumps uses overlapping waves to provide constant power. My sister is having a home built for her family in the hills. Hopefully, she can use this info to choose a set up that can supply her family with constant water. Thanks!

    Reply

  2. One of the water pumps in the city broke a week ago and it got me curious about them! I didn’t know there were different power phases for pumps before. That is really cool that the most common power phases are single and three-phase! Thank you for all the information!

    Reply
  3. Miguel

    Hi We have single phase power available but we want to use a 3 phase in the pump. Is this possible. What is the life span of a 240 vs a 3 phase pump?
    Thank you

    Reply
    • Brian McWhorter

      Miguel,

      Thank you for your question. It is not possible to operate a three phase motor on single phase power without a piece of equipment called a phase converter. Digital phase converters are commonly added to variable frequency drives (VFD), and can be purchased from most motor shops or local electrical contractors. Keep in mind that if you are using a variable frequency drive, you need to either purchase a motor with a shaft grounding ring, or install a shaft grounding ring on your existing motor to insulate the bearings from stray voltage.

      Here are a couple of sites to check our for more information.

      https://wiki.openelectrical.org/index.php?title=Phase_Converter
      http://www.est-aegis.com/datasheets/AEGIS_HVAC_White_Paper.pdf

      Let me know if you have any other questions.

      Reply
  4. Najam Jamal

    Hi,

    I have a scenario in which I have a single phase connection available.

    I need to use a centrifugal pump of 5 hp which will pull water and throw to a stream of 600 ft.

    My queries are

    1. Does single phase hold the load of 5 HP.

    2. If yes will 5 HP pump be good enough to cover the 600 ft distance.

    3. What can be the atlternative with a limitation of having a single phase connection only? Can a phase converter helpful in this scenario in order to make it three phase and use a 3 phase pump?

    Appreciate a swift response.

    Thanks & Regards,

    Najam Jamal

    Reply
    • Brian McWhorter

      Najam,

      Thank you for your questions. Hopefully this helps.

      1. Does single phase hold the load of 5 HP.
      -5 HP motors are commonly run on single phase power. If needed, you could also easily find a 7.5 HP motor that uses single phase power.

      2. If yes will 5 HP pump be good enough to cover the 600 ft distance.
      -Aside from the distance the water needs to travel, there are a few more factors that you will need to take into account when determining the power requirements of an application. This step can be a little involved, so I would recommend that you reach out to a local pump distributor to help you with your specific application. The basic information you will need to know is required flow (GPM), total dynamic head (TDH), specific gravity of the liquid being pumped (1.0 if clean water), and pump efficiency. Your local distributor should be able to help you either find or calculate this information.

      When you have that information you can use this formula to calculate the brake HP:
      Brake HP = (GPM * TDH * specific gravity) / (3960 * pump efficiency)

      3. What can be the alternative with a limitation of having a single phase connection only? Can a phase converter helpful in this scenario in order to make it three phase and use a 3 phase pump?
      -Knowing when to use a phase converter can be a tricky decision. I recommend first doing some research to see if a single phase motor will work, and then revisiting this question if you’re out of options.

      Reply
      • Najam Jamal

        Thanks Brian for prompt response.

        Reply
  5. Hussain

    Very helpful information. I learned a lot from your article.
    Thanks

    Reply

  6. What 3 phase cable size do I need to run two 5.5 KW 3 phase water pumps running in tandem at a distance of 450yards from power supply. The supply is 240v.
    Many thanks

    Reply
    • Brian McWhorter

      Neil,

      Thank you for your question. To be able to size cable, you would also need to know the following information.
      -Amp draw of your motor.
      -Maximum ambient temperature.
      -Allowable voltage drop (usually either 3%-5% of the source voltage).

      If you are powering both motors from a single power source/cable, you would need to rate the cable for both amp draws, or double the cable size requirements of a single motor.

      Hopefully this helps.

      Reply

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