Definite Time, Directional High-Set Elements 67-2, 67N-2 - Siemens siprotec SJ62 User Manual

2.3.2

Definite Time, Directional High-set Elements 67-2, 67N-2

SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015
Phase and ground current are compared separately with the pickup values 67-2
PICKUP and 67N-2 PICKUP of the respective relay elements. Currents above the
setting values are signalled separately when fault direction is equal to the direction
configured. After the user-defined time delays 67-2 DELAY, 67N-2 DELAY have
elapsed, trip signals are issued. Signals are available for each element. The dropout
threshold is roughly equal to 95% of the pickup value for currents greater than > 0.3
I .
Nom
Pickup can be stabilized by setting dropout times 1518 67 T DROP-OUT or 1618 67N
T DROP-OUT. This time is started if the current falls below the threshold and maintains
the pickup condition. The function thus does not drop out instantaneously. The trip
delay time 67-2 DELAY or 67N-2 DELAY continues in the meantime. After the
dropout delay time has elapsed, the pickup is reported OFF and the trip delay time is
reset unless the threshold 67-2 PICKUP or 67N-2 PICKUP has been violated again.
If the threshold is exceeded again while the dropout delay time is still running, it will be
cancelled. The trip delay time 67-2 DELAY or 67N-2 DELAY continues in the mean-
time. If the threshold is still exceeded after the time has elapsed, a trip will be initiated
immediately. If the threshold violation then no longer exists, there will be no response.
If the threshold is exceeded again after the trip command delay time has elapsed and
while the dropout delay time is still running, a trip will be initiated at once.
These elements can be blocked by the automatic reclosure feature (AR).
2.3 Directional Overcurrent Protection 67, 67N
90