Current transformer calibration

Discussion in 'General Electronics Chat' started by sandeep156, May 17, 2013.

  1. sandeep156

    Thread Starter New Member

    May 17, 2013

    I currently have a few split core current transformers (CT) and I would like to connect them to the cables coming out from the feeders at my work place.

    Hovewer, I do not know the value of the current flowing through the cable. So how am I to know if my CTs are giving an accurate reading?

    Should I just use a few CTs on the same cable and compare their values?
    I have tried to look for research papers for CT calibration, but for all of them the current flowing in the conductor (cable) is already known.

    Please suggest where I can find more information on this, or give any ideas.

    Thank you
  2. crutschow


    Mar 14, 2008
    You need to calibrate it with a known current. You can do that with a transformer, a resistor and an ammeter.

    Comparing several CTs on the same cable would be like looking at several clocks. One may have the correct time but how would you know which one does.
  3. richard.cs


    Mar 3, 2012
    You could buy a calibrated clamp meter and put both that meter and one of your current transformers on the cable then compare the readings.

    How much accuracy do you need? Current transformation ratios are pretty much guaranteed by design - it's just the turns ratio. So long as the burden resistor is small enough and the current in the cable low enough to keep the core out of saturation (i.e. follow the manufacturers instructions) you should get the rated accuracy without calibration.
  4. hgmjr

    Retired Moderator

    Jan 28, 2005
    What is the part number of the split core CT that you are using?