User Tag List

Page 2 of 2 FirstFirst 1 2
Results 11 to 16 of 16

Thread: All my VFD's are tripping on Over-voltage

  1. #11
    Join Date
    Feb 2012
    Location
    United States
    Posts
    608
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    480 comes from a transformer from 4160v....

    Might there be a loose connection upstream causing a huge voltage spike? Not so likely with your good fn rf filters, but?

    I too don't see the drive dc bus caps adding with all that isolation between the two voltages.

  2. #12
    Join Date
    Jun 2014
    Location
    Denver
    Posts
    31
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Substation information

    Finally got the trend data from the main substation incoming monitoring relays. Absolutely no incoming voltage spike.

    I'm still at a loss.

  3. #13
    Join Date
    Feb 2012
    Location
    United States
    Posts
    608
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Still at a loss; any of these ideas worth considering?


    1. What is update time on the trend data? If not real time analog, then maybe it missed the spike(s)?
    2. Did an OV fault occur while the data was being recorded?
    3. If so, can you pinpoint that time on the report?
    4. If not, then the data is not of value yet and it still needs to be recorded?
    5. What if there is a loose connection in the downstream 460v common feed area? Maybe you need to record there or right at the input of a drive?

  4. #14
    Join Date
    Dec 2007
    Location
    NE Nebraska
    Posts
    41,346
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by csc_wyo View Post
    Finally got the trend data from the main substation incoming monitoring relays. Absolutely no incoming voltage spike.

    I'm still at a loss.
    Most overvoltage issues I have seen are because of deceleration problems.

    Don't know enough about your application but what are chances of being in a deceleration mode when this is happening, or that a deceleration command is happening even if it is an error?

    Do you have high inertia loads? If so could be the load is "overhauling" the drive output so to speak.

  5. #15
    Join Date
    Sep 2013
    Location
    California
    Posts
    10
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I've been able to correct similar issues in the past with line reactors. Utility company was switching in power correction capacitors at relatively the same time every day causing the issues.

  6. #16
    Join Date
    Dec 2007
    Location
    NE Nebraska
    Posts
    41,346
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by csc_wyo View Post
    Finally got the trend data from the main substation incoming monitoring relays. Absolutely no incoming voltage spike.

    I'm still at a loss.
    This be a local substation to your plant or a POCO substation some distance away?

    Switching capacitors or some other plant going on/off line with a major load, changing taps at regulators all can cause voltage fluctuations or spikes - that may not show up at a distant substation.

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
  •