HOW TO MAXIMIZE PERFORMANCE FROM A ROGOWSKI COIL CURRENT TRANSFORMER
Rogowski coil accuracy is usually calibrated with the conductor centered in the CT window. In practice, however, the CT typically hangs on the conductor which can introduce measurement errors. Note that the error is greatest when the CT connector hangs on the conductor. The following diagram outlines the error introduced simply by moving the conductor to different positions within the opening of the Rogowski coil.
Keep as far as possible, the coil join parallel with the conductor.
Best practice for Rogowski coil installation is to center the conductor as best as conditions allow. In addition, it’s a good idea to keep any other conductors (those you do not wish to measure) at a minimum distance of 2X the diameter of the Rogowski coil CT.
Also, keep in mind that although a Rogowski coil is ideal for large amperage loads, accuracy of the coil may be reduced on smaller loads (<20A).