ABB ret650 - Page 173

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