ABB RELION RET670 - Operating Zones

8.21.2.1 Operating zones
GUID-FE7ADB29-3A48-41BF-AE43-94884D305A29 v2
ImpedanceAn
g
ImpedanceAn
g
ImpedanceAn
g
Z2Fwd
Z3Fwd
Z1Fwd
Z3Rev
Z2Rev
Z1Rev
R(ohm)
X(ohm)
B) Typical setting of zones for under
impedance relay
IEC11000308-3-en.vsd
Zone3
Zone1
REG670
A) Power system model
Zone2
Y/Y
D/Y
IEC11000308 V3 EN-US
1MRK 504 163-UUS A Section 8
Impedance protection
Transformer protection RET670 2.2 ANSI 503
Application manual