User Tag List

Results 1 to 5 of 5

Thread: Delta connection must be calculated to Wye in order to use a third party motor

  1. #1
    Join Date
    Feb 2018
    Location
    Russia
    Posts
    27
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Delta connection must be calculated to Wye in order to use a third party motor

    Hello everyone,
    I faced with the following challenge while commissioning of VFD and third party motor. To use that motor (only Delta) I need to parameterize Drive using calculated to Wye connection values.

    So there are couple of questions:
    • Why some VFD manufacturers allow an usage Wye equivalents only? Are there any technical or programmatical reasons?
    • How to convert Delta connection values to Wye connection ones? Need an example.
    • I mean the following values VL, IL,P.


    Thanks in advance!

  2. #2
    Join Date
    Jul 2006
    Location
    San Francisco Bay Area, CA, USA
    Posts
    8,656
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Chelny View Post
    Hello everyone,
    I faced with the following challenge while commissioning of VFD and third party motor. To use that motor (only Delta) I need to parameterize Drive using calculated to Wye connection values.

    So there are couple of questions:
    • Why some VFD manufacturers allow an usage Wye equivalents only? Are there any technical or programmatical reasons?
    • How to convert Delta connection values to Wye connection ones? Need an example.
    • I mean the following values VL, IL,P.


    Thanks in advance!
    What you are saying makes no sense, you have some sort of misconception taking place here.

    There is no “conversion” to take place, a motor is either wound as delta or wye inside, but that makes zero difference in how a VFD is configured. Whatever the nameplate FLA is will be what you tell the VFD.
    __________________________________________________ ____________________________
    Many people are shocked when they discover I am not a good electrician...

  3. #3
    Join Date
    Feb 2018
    Location
    Russia
    Posts
    27
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Jraef View Post
    Whatever the nameplate FLA is will be what you tell the VFD.
    That's the point! As I told above the motor has Delta connection variant only, and on FLA plate are written values for Delta connection only. That's normally.
    However, VFD's configuring software, for some reasons, requires Wye data only.

    Name:  General_definitions.jpg
Views: 142
Size:  22.6 KB

    P.S. I will try to write a letter to a manufacturer. Thank you!
    Last edited by Chelny; 11-29-18 at 01:13 AM.

  4. #4
    Join Date
    Jul 2006
    Location
    San Francisco Bay Area, CA, USA
    Posts
    8,656
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    That seems misleading to me, I wonder if there is some sort of context missing. All the VFD should care about is the FLA of the motor.

    I’m thinking this relates to a common “trick” used when you want to over speed a motor but get full torque at the higher speed. To do this, you use a dual voltage motor, wire it for the lower voltage but connect it and the VFD to the higher voltage. That way when you increase speed be over the base speed, you can continue to increase voltage as well, keeping the torque constant. In 230/400V IEC dual voltage motors, the higher voltage (400V) is connected to the Wye pattern, the lower voltage (230V) is connected in Delta. But since the current at base motor speed will be higher at the lower voltage, you must select the drive based on that value and program it accordingly. Since Siemens is an IEC mfr, that ended up in their manual. I’m thinking though that there was some preceding context to that statement that you may have missed. Still, very confusing for those unfamiliar with the concept. That was not worded well.

    In your case with a single voltage motor none of that would matter. You will just select and program your drive for what the motor nameplate says, how the motor is internally wired is irrelevant.
    __________________________________________________ ____________________________
    Many people are shocked when they discover I am not a good electrician...

  5. #5
    Join Date
    Dec 2012
    Location
    Placerville, CA, USA
    Posts
    20,230
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Another way to look at this that may be helpful is that regardless of whether the internal configuration is wye or delta the value on the name plate should be the line current, not the phase (line to line) current.
    If this were a single phase heater element instead of a motor, then the phase current (line to line) would not be the same as the line current when three of them were connected to a three phase source.


    Sent from my XT1585 using Tapatalk

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
  •