Definite High-Current Elements 50-2, 50N-2 - Siemens siprotec SJ62 User Manual

2.2.2

Definite High-Current Elements 50-2, 50N-2

SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015
The following table gives an overview of the interconnection to other functions of
7SJ62/63/64.
Table 2-1 Interconnection to other functions
Time Overcurrent Connection to Auto-
Elements matic Reclosing
50-1
50-2
51
50N-1
50N-2
51N
Phase and ground currents are compared separately with the pickup values of the
high-set elements 50-2 and 50N-2. If the respective pickup value is exceeded this is
signalled. After the user-defined time delays 50-2 DELAY or 50N-2 DELAY have
elapsed, trip signals are issued. Signals are available for each element. The dropout
value is roughly equal to 95% of the pickup value for currents greater than > 0.3 I
Pickup can be stabilized by setting dropout times 1215 50 T DROP-OUT or 1315 50N
T DROP-OUT. This time is started and maintains the pickup condition if the current falls
below the threshold. The function thus does not drop out instantaneously. The trip
delay time 50-2 DELAY or 50N-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 50-2 PICKUP or 50N-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 50-2 DELAY or 50N-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 violated 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).
2.2 Overcurrent Protection 50, 51, 50N, 51N
Manual
CLOSE
• •
• •
• •
• •
• •
• •
Dynamic Cold Inrush Restraint
Load Pickup
•
•
•
•
•
•
•
•
•
•
.
Nom
60