duplicating a current transformer output

Discussion in 'The Projects Forum' started by TLJ, Feb 11, 2009.

  1. TLJ

    Thread Starter New Member

    Feb 11, 2009
    I would like to be able to test a current sensing relay. (A field application relay for a synchronous motor.)
    This relay looks for a drop in inrush current, from over 300 amps to around 150 amps. The CT output falls from 15 to 3 amps, indicating the motor has reached the proper speed. The ratio dosent appear linear but thats how it looks when it works
    Would this be as simple as a 120v isolation transformer with a variable resister?
    Or should I use an actual CT and somehow get the ratio correct for a more reasonable primary current.