Phase dropping out when supply turned on.

Discussion in 'General Electronics Chat' started by grknox, Mar 10, 2014.

  1. grknox

    Thread Starter New Member

    Mar 10, 2014
    Any advice appreciated.

    Over a year ago completed the mains supplies for 3 wind turbines.

    Scottish Power meter head 3 Phase comes into a 3 phase meter. Then from that a 3 ph mains supply into a Triple Pole and Neutral Board.

    From the board each of the wind turbines are supplied by a separate 63amp TP mcb. This goes to a separate isolator for each turbine.

    The Turbine installers informed me that there is a problem with one of the phases.

    Checked out. When all the isloators are off to supply the turbines I get the correct voltage across each ph and to N and earth..

    Between Ph and Neutral I get 244 volts. As soon as I turn on any of the isolators for the turbines the middle phase drops down to 190 volts and causes all sorts of probems.

    Any ideas what could be causing this..
  2. tcmtech

    Well-Known Member

    Nov 4, 2013
    Sounds like you have a dead phase on the primary side of the system so you are getting phase angle drift when the system loads up.