Accuracy Class
A designation assigned to a current transformer the errors of which remain within specified limits under prescribed conditions of use.
Burden
The value of the impedance of the secondary circuit expressed in ohms or in Volt-Amperes at the rated secondary current at the relevant power factor.
Rated Accuracy Limit Factor
The ratio of the rated accuracy limit primary current to the rated primary current.
Rated Accuracy Limit Primary Current
The value of primary current up to which the transformer will comply with the requirements for composite error.
Standard Accuracy Limit Factors
The standard accuracy limit factors are 5-10-15-20-30
Standard Accuracy Class
The standard accuracy class for protective current transformer are 5P and 10P
Composite Error
Under steady state conditions , the rms value of the difference between the instantaneous values of the primary current and instantaneous value of the actual secondary current multiplied by the rated transformer ratio.
