Define the phase angle error (θ) in a current transformer instrument, wherein

Im = Magnetizing component of exciting current,

δ = Angle between secondary induced voltage and secondary current

Ic = Core loss component of exciting current

n = turns ratio

Is = Secondary winding current  

Ip Primary winding current 

The correct answer is option 1):

Concept:

• The phase angle between the primary and secondary of the current transformer must be 180 degrees.
• The primary and secondary current must be out of phase.
• The deviation in the phase angle of the primary and secondary current is called the phase angle error.

​​">θ=Im Cosδ−Ic SinδnIsdegreeθ=Im Cosδ−Ic SinδnIsdegreeθ=Im Cosδ−Ic SinδnIsdegree $\rm \theta=\frac{Im \ Cos \delta-Ic \ Sin \delta}{nIs} degree$

m = Magnetizing component of exciting current,

δ = Angle between secondary induced voltage and secondary current

Ic = Core loss component of exciting current

n = turns ratio

Is = Secondary winding current  

Ip= Primary winding current