ABB RET650 Technical Manual page 173

1MRK 504 135-UEN A
Technical manual
Characteristic
for STRV
-RCA +85 deg
RCA -85 deg
Characteristic for forward
release of measuring steps
IEC11000243 V1 EN
Figure 71: Operating characteristic for earth-fault directional element using the
zero sequence components
Operating area
STRV
0.6 * IN>DIR
Characteristic for reverse
release of measuring steps
40% of
IN>DIR
RCA
65°
I
op
Operating area
Characteristic
for STFW
Section 8
Current protection
-RCA -85 deg
U
IN>DIR
STFW
= 3I
0
IEC11000243-1-en.ai
RCA +85 deg
= -3U
pol 0
167