GE MiCOM P145 Agile - Earth Fault Protection; Directional Elements; Non-Directional Elements; SEF Protection (Residually Connected)

Instantaneous phase overcurrent elements
V I R R R
K sp CT L p
= + +( )
2.2 EARTH FAULT PROTECTION
2.2.1 DIRECTIONAL ELEMENTS
Instantaneous earth fault overcurrent elements
V
I
R R R Rn
K
fn
CT L p
= + + +
2
2( )
2.2.2 NON-DIRECTIONAL ELEMENTS
Time-delayed earth fault overcurrent elements
V
I
R R R R
K
cn
CT L p n
= + + +
2
2( )
Instantaneous earth fault overcurrent elements
V I R R R R
K sn CT L p n
= + + +( )2
2.3 SEF PROTECTION (RESIDUALLY CONNECTED)
2.3.1 DIRECTIONAL ELEMENTS
Time delayed SEF protection
V
I
R R R Rn
K
cn
CT L p
≥ + + +
2
2( )
Instantaneous SEF protection
V
I
R R R Rn
K
fn
CT L p
≥ + + +
2
2( )
2.3.2 NON-DIRECTIONAL ELEMENTS
Time delayed SEF protection
V
I
R R R Rn
K
cn
CT L p
≥ + + +
2
2( )
Instantaneous SEF protection
V
I
R R R Rn
K
sn
CT L p
≥ + + +
2
2( )
P14x Chapter 9 - Current Transformer Requirements
P14xEd1-TM-EN-1 201