EN 60255-121:2014

FOREWORD
1 Scope
2 Normative references
3 Terms and definitions
4 Specification of the function
5 Performance specifications
6 Functional tests
7 Documentation requirements
Annex A (informative) - Impedance characteristics
Annex B (informative) - Informative guide for
        the behaviour of timers in distance protection
        zones for evolving faults
Annex C (normative) - Setting example
Annex D (normative) - Calculation of mean, median
        and mode
Annex E (informative) - CT saturation and influence
        on the performance of distance relays
Annex F (informative) - Informative guide for testing
        distance relays based on CT requirements specification
Annex G (informative) - Informative guide for
        dimensioning of CTs for distance protection
Annex H (normative) - Calculation of relay settings
        based on generic point P expressed in terms of
        voltage and current
Annex I (normative) - Ramping methods for testing the
        basic characteristic accuracy
Annex J (normative) - Definition of fault inception angle
Annex K (normative) - Capacitive voltage instrument
        transformer model
Annex ZA (normative) - Normative references to
         international publications with their
         corresponding European publications