Current Transformer Requirements
The requirements for phase current transformers are usually determined by the overcurrent time protection,
particularly by the high-current element settings. Besides, there is a minimum requirement based on experi-
ence.
The recommendations are given according to the standard IEC 60044-1.
The standards IEC 60044-6, BS 3938 and ANSI/IEEE C 57.13 are referred to for converting the requirement into
the knee-point voltage and other transformer classes.
D.1 Accuracy limiting factors 370
D.2 Class conversion 371
D.3 Cable core balance current transformer 372
D
SIPROTEC 4, 7SJ61, Manual 369
C53000-G1140-C210-6, Edition 05.2016