Class Accuracy - Siemens 7SK80 Manual

Appendix
A.4 Current Transformer Requirements

Class accuracy

Table A-2
Neutral point
Function directional
Function non-directional
For extremely small ground fault currents it may become necessary to correct the angle at the device (see func-
tion description of „sensitive ground fault detection").
444
Minimum required class accuracy depending on neutral grounding and function operating prin-
ciple
isolated
Class 1
Class 3
resonant-grounded
Class 1
Class 1
E50417-G1140-C344-A5, Release date 11.2012
high-resistance ground-
ed
Class 1
Class 3
SIPROTEC, 7SK80, Manual