73
Figure 48: CT Ratio Test Results - Concurrent
Polarity: Unit automatically determines the polarity connections and displays the result as either
polarity Correct or Incorrect. The phase angle deviation between the secondary and primary
voltage is also displayed along with polarity.
The ratio is defined as the number of turns in the secondary as compared to the
number of turns in the primary.
N2/N1=V2/V1
Where,
N2 and N1 are no. of turns of secondary and primary windings respectively
V2 and V1 are the secondary and primary side voltage readings respectively.
A suitable voltage, below saturation is applied to the secondary of the CT under test
and primary side voltage is measured to calculate the turns ratio from above
expression.