Page 1 of 2 12 LastLast
Results 1 to 15 of 22
  1. #1
    Join Date
    Aug 2006
    Location
    Melbourne
    Posts
    1,105

    Default Anyone running 3 phase coolant pump on single phase?

    Hi all,

    Just wondering if anyone has had any luck running a 3 phase coolant pump on single phase, it seems you can get them working with a capacitor. https://www.youtube.com/watch?v=RLaBVY1yN44
    The pump I have is 85 Watts and can be configured for either 415 or 240V.

    I do have a small 0.25kw VFD that I can use but it seems a waste to use it on a coolant pump, I have no desire to have variable speed at all.

    Thanks

  2. #2
    Join Date
    Aug 2006
    Location
    Melbourne
    Posts
    1,105

    Default

    Here is a photo of the name plate1540113310157~2.jpg

    Sent from my SM-G935F using Tapatalk

  3. #3
    BobL is online now Member: Blue and white apron brigade
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    7,182

    Default

    I'm running one on 240 but it's via a small VFD.

    At least your motor is 240V 3P convertible - the Y -> ∆ conversion on mine involved wires that were almost as thin as human hair. The pump on mine was a solid ball of corrosion and needed a lot of work to get it back to operational.

    After going to all that trouble I have used it a grand total of once because I am using an coolant misting system with ATF and this is works more or less OK. I can see on some cuts it night still be useful to have flood coolant.

    Pumps are funny things - you can't derate them much so running the 3P pump motor via SP plus a cap may not provide the grunt required but it should be worth a try. Pump motor may also run hotter - you'd need to watch this.

  4. #4
    Join Date
    Aug 2006
    Location
    Melbourne
    Posts
    1,105

    Default

    I might give it a try, what size cap would be best to use? It will be used on a drill press so it won't be on for long periods of time.

  5. #5
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,436

    Default

    Hi Com_VC,

    85 Watts is not a lot for a drill press ! Unless you're only going to use it for little drills, say 1/8" or less.

    Anyway I would try 15 to 20 uf for a start.
    Best Regards:
    Baron J.

  6. #6
    Join Date
    Aug 2006
    Location
    Melbourne
    Posts
    1,105

    Default

    Hi BaronJ,

    It will be used as a coolant pump on the drill press

  7. #7
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,436

    Default

    Hi Com_VC,

    Actually using a coolant pump as a coolant pump never occurred to me I did think "small drill press" though, I have seen one designed to drill holes in pcb's using a 135 W brush motor.

    If you get stuck for capacitors, old fluorescent fittings usually have one of about 8 uf. If the capacitor you have is too small you can connect another one, two or three in parallel to increase the value. Capacitors in parallel add their values together.
    Best Regards:
    Baron J.

  8. #8
    Join Date
    Aug 2006
    Location
    Melbourne
    Posts
    1,105

    Default

    Would these be the ones?1540206493078~2.jpg

    Sent from my SM-G935F using Tapatalk

  9. #9
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,436

    Default

    Hi Com_VC,

    No ! They are glow starters for starting the tube. The capacitors will be inside the body of the fitting and are usually round cylinders and silver in colour. The other Item in there will be the choke, which is basically a coil of wire around a laminated iron core.

    Their will almost certainly have the capacitor value and a voltage rating marked on them.

    I actually had one in my hand earlier today whilst looking for something else.
    Best Regards:
    Baron J.

  10. #10
    Join Date
    Aug 2006
    Location
    Melbourne
    Posts
    1,105

    Default

    Thought they looked a bit unusual. Will have another look tonight. Think I should have something around.

  11. #11
    Join Date
    Aug 2006
    Location
    Melbourne
    Posts
    1,105

    Default

    So I had a chance to have a play around with this today after work. I found two light fixtures, each had a 4 uf cap. So I figured I would grab one of them for now and wire it up to see what happens. What do you know, it actually works, it spun right up and sounded healthy. I only ran it for 10 seconds as it is dark now.

    I want to do some proper testing with some water and run it continuous for 30 minutes to see how it flows and if it develops the height I require. Also to monitor the temperature.

  12. #12
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,436

    Default

    Hi Com_VC,

    The motor speed is determined by the frequency of the supply voltage, so irrespective of the capacitor value it won't alter the motor speed.
    What will alter is how hot the windings will get ! So keep a close eye on the temperature. I think 4 uf might just be a little small, but at least you now know that it works and pumps OK.

    Re temperature. The winding that has the full voltage on it will be the coolest. The capacitor value will determine the current through the other windings.
    Under ideal conditions the current through each winding should be the same under load. One way to measure this is to use a clamp ammeter on each power lead in turn, and adjust the capacitor value to get even current on all three leads.
    Best Regards:
    Baron J.

  13. #13
    Join Date
    Nov 2017
    Location
    Geelong, Australia
    Age
    57
    Posts
    2,651

    Default

    And do that tuning while it's under load i.e. Pumping, not just spinning freely.

    Steve

  14. #14
    Join Date
    Aug 2006
    Location
    Melbourne
    Posts
    1,105

    Default

    I just ran it for a full 10 minutes in a bucket with some water in it and it didn't get hot at all, just slightly warm. So either I fluked it or the value of the cap is pretty close. I am still going to measure it just to make sure it is 100%.

    Then I am faced with how I should mount the cap, is it OK to mount it externally or should I modify the motor terminal box to somehow incorporate the cap and wiring all together?

  15. #15
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    6,436

    Default

    Hi Com_VC,

    Depending upon how big the capacitor is, you could just use a plastic cap to cover the terminals and mount it anywhere reasonable. Or a plastic box, like those project boxes with a lid that is secured by a screw in each corner. Don't forget to make sure that you have a safety earth connection to the motor and include the capacitor case if its metal.
    Best Regards:
    Baron J.

Page 1 of 2 12 LastLast

Similar Threads

  1. Replies: 26
    Last Post: 20th Sep 2018, 07:35 PM
  2. Replies: 0
    Last Post: 27th Jul 2018, 09:12 PM
  3. Powering a 3phase pump with single phase
    By MOA in forum METALWORK GENERAL
    Replies: 13
    Last Post: 15th Jul 2015, 06:59 AM
  4. 240v single phase to 415v 3 phase conversion
    By Oldneweng in forum METALWORK GENERAL
    Replies: 81
    Last Post: 12th Jul 2012, 05:58 PM
  5. Replies: 14
    Last Post: 4th May 2012, 08:48 AM

Posting Permissions

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