Fast Trip In Switch On To Fault - ABB 615 series Technical Manual

1MAC059074-MB A
9.4.6.6
615 series ANSI
Technical Manual
Example 1
When a two-shot-sequence is used, the pickup information from the protection function is
routed to the DEL_INIT 2 input and the trip information to the INIT_2 input. The
following conditions have to apply:
• protection trip time = 0.5s
• Str 2 delay shot 1 = 0.05s
• Str 2 delay shot 2 = 60s
• Str 2 delay shot 3 = 60s
Operation in a permanent fault:
1. Protection picks up and activates the DEL_INIT 2 input.
2. After 0.05 seconds, the first autoreclose shot is initiated. The function opens the
circuit breaker: the OPEN_CB output activates. The total trip time is the protection
pickup delay + 0.05 seconds + the time it takes to open the circuit breaker.
3. After the first shot, the circuit breaker is reclosed and the protection picks up again.
4. Because the delay of the second shot is 60 seconds, the protection is faster and trips
after the set operation time, activating the INIT 2 input. The second shot is initiated.
5. After the second shot, the circuit breaker is reclosed and the protection picks up again.
6. Because the delay of the second shot is 60 seconds, the protection is faster and trips
after the set operation time. No further shots are programmed after the final trip. The
function is in lockout and the sequence is considered unsuccessful.
Example 2
The delays can be used also for fast final trip. The conditions are the same as in Example
1, with the exception of Str 2 delay shot 3 = 0.10 seconds.
The operation in a permanent fault is the same as in Example 1, except that after the second
shot when the protection picks up again, Str 2 delay shot 3 elapses before the protection
trip time and the final trip follows. The total trip time is the protection pickup delay + 0.10
seconds + the time it takes to open the circuit breaker.

Fast trip in Switch on to fault

The Str _ delay shot 4 parameter delays can also be used to achieve a fast and accelerated
trip with SOTF. This is done by setting the Fourth delay in SOTF parameter to "1" and
connecting the protection pickup information to the corresponding DEL_INIT_ input.
When the function detects a closing of the circuit breaker, that is, any other closing except
the reclosing done by the function itself, it always prohibits shot initiation for the time set
with the Reclaim time parameter. Furthermore, if the Fourth delay in SOTF parameter is
"1", the Str _ delay shot 4 parameter delays are also activated.
Section 9
Control functions
1025