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!


  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!

  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

    • Brian McWhorter


      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.


      Let me know if you have any other questions.

  4. Najam Jamal


    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

    • Angel

      I received a chart on how to obtain a meter. I don’t which one one should i go for. Is it single phase or three phase meter. Presently, i have a 0.5 horse power pumping machine using to pump water. Hopefully, to join this with AC, water heater and electric cooker. I don’t know whether single phase meter can take care of all aforementioned items.

  5. Hussain

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


  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

    • Brian McWhorter


      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.

  7. Jeff M.

    I want to install a 3 phase (208v) standby generator at my residence. The grid is a delta configuration or stinger leg. The only 3 phase equipment is a submersible well pump. Does the standby generator need to produce power with one leg as a stinger?

    • Brian McWhorter


      Thank you for your question. If the motor on your submersible pump is 3 phase, you will need to use the high-leg of your generator to operate it.

      Here is a helpful article that may explain things more completely.


      Hopefully this helps.

  8. rk

    I would like to know single phase and three phase submersible pump advantage.
    If I use three phase motor, my power cost comes down? or single phase pump will consume higher current?

    • Janak Mathukiya

      I want to run single phase motor pump which is 5 HP and it draws 30 amps and it is 4000 feet away from my farm , I want to run it from my farm so how do I choose the cable size to supply 30 amps to motor

      • Brian McWhorter


        Thank you for your question. I would recommend reaching out to a local wire/cable provider to see what they would recommend based on what they stock. There is a little more to take into account than what you have provided. I would recommend Cerrowire as a good online vendor.


        They will need the following information to size the proper cable.

        Length of cable run
        Phase of power
        Construction of conductor (Copper or Aluminum)
        Type of Installation (buried, conduit, overhead)
        Voltage drop (3% recommended)
        Current at the end of run (motor voltage plus safety factor)
        Number of parallels (they can help you with this portion)

        I hope this helps!

  9. Manu Mark

    While using a 3 phase 5HP submersible agricultural pumpset, at times 2 phase is provided. An autostarter switch is used, which means the pumpset may run on the 2 phases and burnout.
    Please name and describe a tool to prevent 2 phase run and burnout.
    Can a protector be installed within the motor to stop it when 2 phases alone are provided?

    • Brian McWhorter


      I would recommend contacting your power provider and see why the third leg of power is being lost. There are protectors you can purchase. I would recommend Googling a electrical control panel shop in your area. They should be able to provide a control to prevent the pump from engaging when you are having power issues.

  10. jun

    I would like to ask if there is any way i can use vfd in my single phase water pump. my power source is 3 phase but the vfd available in our local store has single phase input and 3 phase output. how can i use this vfd in my single phase water pump?

    I will be appreciate your response. thanks

    • Brian McWhorter


      Thank you for your question.

      There are a few options to convert three phase incoming power to a single phase output. There are drives available with these capabilities built in, but here is a quick summary of a few ways the conversion could take place.

      1. Convert the incoming three phase AC power to DC using an electronic rectifier, and then convert the DC power to single phase AC using a single phase inverter.
      2. Use a single phase transformer across two phases of the incoming power. This is only acceptable up to about 400 volts.
      3. Use a open delta transformer. Using this transformer effectively double the acceptable voltage rating as compared to a single phase transformer.

      I recommend talking to a local control shop for their recommendation. All of these options should be reviewed and implemented by an experienced electrician.

      Have a great day!

  11. Prashant

    Three or single phase pump
    Which pump give more water having same HP

    • Brian McWhorter


      Please note that the phase is a characteristic of the motor and not the pump. At the same HP, the phase will have no effect on the performance of the pump.

      Have a great day!

  12. Sandy

    How to identify the motor are of single phase or a three phase.if there is no name place on motor?
    Using multimeter…..?

  13. bart collins

    For my new home 15 years ago the well installer talked me into a VFD 3phase system instead of a single phase and traditional expansion tank. Since then, the well company has had to replace the franklin VFD unit 7 times due to failures, some months apart, some lasting a few years. I have spent nearly $8,000 in VFD replacement and service calls. There are multiple ground rods on the electric system and lightning/surge protection on both the VFD incoming line, line from well, and one on the power supply to the VFD. The failures always occur during a severe rain or lightning storm. The last controller cost me $3200, which is completely absurd. The well installer would not come out until I paid him up from for a controller that had failed 2 months earlier. Franklin has changed their warranty from 5 yrs to 3 years. I cant pay $3200 every 3 years for a failed controller.
    Do you have any suggestions on replacing the franklin with a cheap alternatve or should I remove the system and replace it with single phase equipment?

    • Brian McWhorter


      I’m sorry, that sounds very frustrating. I’ll send you an email so we can discuss this a little further.

      Best regards,

      Brian McWhorter


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