523,728 active members*
1,922 visitors online*
Register for free
Login
IndustryArena Forum > CNC Electronics > Spindles / VFD > Limiting current on a 2.2 kW VFD/spindle combo for 110V/20A breakers
Results 1 to 10 of 10
  1. #1

    Join Date
    Jun 2020
    Posts
    4

    Limiting current on a 2.2 kW VFD/spindle combo for 110V/20A breakers

    Hi everyone,

    I am currently building my first CNC machine (PrintNC) and am a total newbie, so please excuse if this question is obvious for you the experts.

    Being in the US on 110V 20A circuits, I ordered a Huang Yang 1.5kW VFD/spindle combo online, but "unfortunately" the vendor sent me a 2.2kW combo.

    https://prom-electric.ru/media/hy01d523b.pdf

    Being borderline for my circuits, I am hoping I can limit the current using the PD142 function to "fake" the rated current of the spindle and reduce to it 13A to get close to 1.5kW, assuming this is what the 1.5kW/110V VFD model should be set at. Is that the correct approach? Any risk the breakers on which the VFD and spindle are individually connected to would trip?

    Thanks in advance for your help.

  2. #2

    Join Date
    Jun 2020
    Posts
    4

    Re: Limiting current on a 2.2 kW VFD/spindle combo for 110V/20A breakers

    I will rephrase my question to be more straight forward:

    If I limit the output current of the VFD from 20A to 13A , does this "convert" the 2.2kW VFD/spindle combo to 1.5kW?

  3. #3
    Member
    Join Date
    Dec 2012
    Posts
    100

    Re: Limiting current on a 2.2 kW VFD/spindle combo for 110V/20A breakers

    Hello.

    In a sense you do. By limiting the current you ensure that overloads do not lead to motor overheating and getting burned, in particular when the driven motor is of lower specs than the drive.

    It would also help to use the external braking resistor. Check with your supplier.

    I hope this clears things a little.

    Regards.

  4. #4
    Registered
    Join Date
    May 2011
    Posts
    637

    Re: Limiting current on a 2.2 kW VFD/spindle combo for 110V/20A breakers

    I don't really have enough info to give an opinion on what you should do.

    Is the 2.2 kW spindle supposed to be run on 220V? Have you got a manual for the actual spindle?

    Also, on good quality spindles, the power rating is the power output of the spindle, not the power input. Your spindle motor is not 100% efficient in converting electricity to rotational power at the spindle output. On Chinese spindles, they do whatever they feel like when making up the numbers. Is this a Russian spindle?

    Quote Originally Posted by mokuleia View Post
    Hi everyone,

    Being in the US on 110V 20A circuits, I ordered a Huang Yang 1.5kW VFD/spindle combo online, but "unfortunately" the vendor sent me a 2.2kW combo.

    https://prom-electric.ru/media/hy01d523b.pdf
    The link you posted if you scroll down a few pages to "Standards and Specifications", there is no Single Phase 110V option listed as an input for the VFD.

    Quote Originally Posted by mokuleia View Post
    I will rephrase my question to be more straight forward:

    If I limit the output current of the VFD from 20A to 13A , does this "convert" the 2.2kW VFD/spindle combo to 1.5kW?
    No it won't.

    If the V/f curve (Voltage / frequency) for your spindle is a straight line, which it might be, then running it at 110V (assuming that it is a 220V spindle) and setting the max current to the max current for the spindle as per the spindle manual (assuming that this is less than 20 amps), should get you identical performance up to 1/2 of the maximum RPM of that spindle, if you were driving it at 220V, but will not give you the same performance you would get from the 1.5 kW spindle. My guess is that you'd have more torque at low RPM with the 220V, and after you get to the point on the V/f curve where Voltage surpasses 110V (guessing this happens at about half of full RPM for your spindle) then the performance would go down from expected values, I don't know how much.

    You will never "convert" it to give the same performance as the 1.5 kW, IMO.

    And it is better, IMO, to run at the correct current at a lower voltage, than the other way around.

    Your big problem is that your VFD does not appear to have single phase 110V input from the brief look I had at the manual.

  5. #5
    Community Moderator ger21's Avatar
    Join Date
    Mar 2003
    Posts
    34987

    Re: Limiting current on a 2.2 kW VFD/spindle combo for 110V/20A breakers

    Based on what you're saying, it sounds like you have a 110V 2.2kw spindle and VFD, with the spindle rated at 20 amps? If so, then yes, limiting the current effectively makes it a 1.5Kw spindle. There's nothing wrong with using a VFD with a higher KW rating then the spindle.
    Gerry

    UCCNC 2017 Screenset
    http://www.thecncwoodworker.com/2017.html

    Mach3 2010 Screenset
    http://www.thecncwoodworker.com/2010.html

    JointCAM - CNC Dovetails & Box Joints
    http://www.g-forcecnc.com/jointcam.html

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)

  6. #6

    Join Date
    Jun 2020
    Posts
    4

    Re: Limiting current on a 2.2 kW VFD/spindle combo for 110V/20A breakers

    Thank you all for the replies. Let me had some details.

    I confirm that the VFD and spindle are both 110V, not 220V. The link to the manual was just to reference to current limit function (P142). I include pictures of the spindle and VFD below with electrical specs. Surprisingly, the current rating on the spindle is 8.5A, so not sure where the 2.2kW comes from...Is that current per conductor?

    I have read also that the current input for the VFD is nearly double that of the output. If that is correct, I would need 40A in to get the 20A output stated on the plate.

    To be clear, I got this 2.2kW/110V combo from a CNC stater kit on Aliexpress. I am not sure if I can return it free of charge and the only thing I could get as replacement is a 1.5kW/110V combo. There are 220V options, but I have only three 20A/110V breakers in my little shop, so running 220V lines migth be hard.

    Knowing these specs and the fact that I paid a 2.2kW combo for the price of a 1.5kW, do you see any benefit in swapping the 2.2kw for the 1.5kw? Would not running the 2.2kw at 60% (1.5kw/2.2kw) give me about the same performance compared to the 1.5kw at 100%?

    More importantly, will the 110V/20A breaker on which the VDF is solely connected being able to handle the load if the output current going to the spindle (connected to a different 110V/20A breaker) is 13A (see above comment about current IN being 2X of current OUT)?

  7. #7
    Community Moderator ger21's Avatar
    Join Date
    Mar 2003
    Posts
    34987

    Re: Limiting current on a 2.2 kW VFD/spindle combo for 110V/20A breakers

    You should be setting the VFD to output 8.5 amps, which is the rating for the spindle you have.
    Gerry

    UCCNC 2017 Screenset
    http://www.thecncwoodworker.com/2017.html

    Mach3 2010 Screenset
    http://www.thecncwoodworker.com/2010.html

    JointCAM - CNC Dovetails & Box Joints
    http://www.g-forcecnc.com/jointcam.html

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)

  8. #8
    Member
    Join Date
    Jan 2005
    Posts
    11198

    Re: Limiting current on a 2.2 kW VFD/spindle combo for 110V/20A breakers

    Quote Originally Posted by mokuleia View Post
    Thank you all for the replies. Let me had some details.

    I confirm that the VFD and spindle are both 110V, not 220V. The link to the manual was just to reference to current limit function (P142). I include pictures of the spindle and VFD below with electrical specs. Surprisingly, the current rating on the spindle is 8.5A, so not sure where the 2.2kW comes from...Is that current per conductor?

    I have read also that the current input for the VFD is nearly double that of the output. If that is correct, I would need 40A in to get the 20A output stated on the plate.

    To be clear, I got this 2.2kW/110V combo from a CNC stater kit on Aliexpress. I am not sure if I can return it free of charge and the only thing I could get as replacement is a 1.5kW/110V combo. There are 220V options, but I have only three 20A/110V breakers in my little shop, so running 220V lines migth be hard.

    Knowing these specs and the fact that I paid a 2.2kW combo for the price of a 1.5kW, do you see any benefit in swapping the 2.2kw for the 1.5kw? Would not running the 2.2kw at 60% (1.5kw/2.2kw) give me about the same performance compared to the 1.5kw at 100%?

    More importantly, will the 110V/20A breaker on which the VDF is solely connected being able to handle the load if the output current going to the spindle (connected to a different 110V/20A breaker) is 13A (see above comment about current IN being 2X of current OUT)?
    You really should make the seller take it back and give you the 1.5Kw spindle the 2.2Kw spindle will not perform very well being 110v the US and all of NA supply is 120v the 2.2Kw @110v is not 8.5A

    The VFD Drive would be fine for the 1.5Kw but not for the 2.2Kw you would need a 30A supply to run that spindle at 2.2Kw on 120v and the VFD Drive has a max of 20A so is not suitable for that spindle

    Dumbing down the spindle it will stall even with light cuts as it won't have the torque at it's max operating speed

    Correct the current in is roughly twice the output current, so you only have a supply that will run a 1.5Kw not a 2.2Kw
    Mactec54

  9. #9

    Join Date
    Jun 2020
    Posts
    4
    Quote Originally Posted by mactec54 View Post
    You really should make the seller take it back and give you the 1.5Kw spindle the 2.2Kw spindle will not perform very well being 110v the US and all of NA supply is 120v the 2.2Kw @110v is not 8.5A

    The VFD Drive would be fine for the 1.5Kw but not for the 2.2Kw you would need a 30A supply to run that spindle at 2.2Kw on 120v and the VFD Drive has a max of 20A so is not suitable for that spindle

    Dumbing down the spindle it will stall even with light cuts as it won't have the torque at it's max operating speed

    Correct the current in is roughly twice the output current, so you only have a supply that will run a 1.5Kw not a 2.2Kw
    If i understand you, one should drive a 1.5kw spindle with a 2.2kw vfd, a 0.8kw spindle with 1.5kw vfd...etc?

  10. #10
    Member
    Join Date
    Jan 2005
    Posts
    11198

    Re: Limiting current on a 2.2 kW VFD/spindle combo for 110V/20A breakers

    Quote Originally Posted by mokuleia View Post
    If i understand you, one should drive a 1.5kw spindle with a 2.2kw vfd, a 0.8kw spindle with 1.5kw vfd...etc?
    Correct, especially for single phase use because the VFD Drive need more input current
    Mactec54

Similar Threads

  1. Help with current limiting resistors
    By Zeljkoc in forum Stepper Motors / Drives
    Replies: 7
    Last Post: 10-25-2010, 11:06 PM
  2. Questions about current limiting
    By uplb in forum General CNC Machine Related Electronics
    Replies: 3
    Last Post: 10-04-2008, 05:19 PM
  3. Current Limiting For Steppers
    By waleed alhadidi in forum General CNC Machine Related Electronics
    Replies: 10
    Last Post: 11-11-2007, 01:44 PM
  4. current limiting R2 & R4?
    By obscurity in forum PicStep Controllers
    Replies: 1
    Last Post: 07-18-2006, 04:25 AM
  5. Current limiting resistor
    By pyrojon in forum General CNC Machine Related Electronics
    Replies: 8
    Last Post: 04-20-2005, 02:47 AM

Tags for this Thread

Posting Permissions

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