ABB REC650 ANSI Technical Manual page 118

Section 6
Current protection
112
Characteristic
for PUREV
-RCA +85 deg
RCA -85 deg
Characteristic for forward
release of measuring steps
ANSI11000269 V2 EN
Figure 40: Operating characteristic for ground-fault directional element using the
negative sequence components
Two relevant setting parameters for directional supervision element are:
• Directional element will be internally enabled to operate as soon as Iop is bigger than
40% of IDirPU and directional condition is fulfilled in set direction.
• Relay characteristic angle AngleRCA, which defines the position of forward and
reverse areas in the operating characteristic.
Directional comparison step, built-in within directional supervision element, will set
EF4PTOC (51N/67N) function output binary signals:
Operating area
PUREV
0.6 * IDirPU
Characteristic for reverse
release of measuring steps
40% of
IDIR
RCA
65 deg
I = 3I
op
Operating area
Characteristic
for PUFW
1MRK 511 287-UUS A
-RCA -85 deg
V
pol = -
IDIR
PUFW
2
ANSI11000269-2-en.ai
Technical manual
RCA +85 deg
V
2