Functions
2.12 Intermittent Ground Fault Protection
SIPROTEC, 7SK80, Manual
E50417-G1140-C344-A5, Release date 11.2012
210
Table 2-12 shows all messages subject to a restraint mechanism avoiding a message burst during an intermit-
tent ground fault:
Table 2-12 Buffered Indications
Before they are entered in the fault log (event buffer) and transmitted to the system interface or CFC, the indi-
cations of Table 2-12 are buffered (starting with the incoming indication „Intermitt.EF“). The buffering does
not apply to signaling to relays and LEDs as it is required by time-graded protection systems for reverse inter-
locking. The buffer can store a maximum of two status changes (the most recent ones) for each indication.
Buffered messages are signaled to the fault log, CFC and to the system interface with the original time flag only
when a TRIP command is initiated by a protection function other than the intermittent ground fault protection.
This ascertains that a pickup, although delayed, is always signaled in association with each TRIP command.
All pickup indications which usually do not occur during an intermittent ground fault are not affected by this
mechanism. Among others this includes the pickup and TRIP commands of the following protection functions:
• Circuit breaker failure protection,
• overload protection,
• frequency protection and
• voltage protection
The pickup signals of these functions will still be logged immediately. A TRIP command of one of these pro-
tective functions will cause the buffered messages to be cleared since no connection exists between tripping
function and buffered message.
FNo. Indication Explanation
1761 „50(N)/51(N) PU“ V50(N)/51(N) pickup
1762 „50/51 Ph A PU“ VPhase A inrush picked up A
1763 „50/51 Ph B PU“ VPhase B inrush picked up B
1764 „50/51 Ph C PU“ VPhase C inrush picked up C
1767 „50-3 picked up“ 50-3 Element picked up
1810 „50-1 picked up“ 50-1 Element picked up
1820 „51 picked up“ 51 Element picked up
1768 „50N-3 picked up“ 50N-3 Element picked up
1831 „50N-2 picked up“ 50N-2 Element picked up
1834 „50N-1 picked up“ 50N-1 Element picked up
1837 „51N picked up“ 51N Element picked up
2691 „67/67N pickedup“ 67/67N picked up
2697 „67N-3 picked up“ 67N-3 Element picked up
2646 „67N-2 picked up“ 67N-2 Element picked up
2681 „67N-1 picked up“ 67N-1 Element picked up
2684 „67N-TOCPickedup“ 67N-TOC Element picked up
2695 „67N picked up“ 67N Ground picked up
5159 „46-2 picked up“ 46-2 picked up
5165 „46-1 picked up“ 46-1 picked up
5166 „46-TOC pickedup“ 46-TOC picked up
1215 „64 Pickup“ 64 displacement voltage picked up
1221 „50Ns-2 Pickup“ 50Ns-2 Element picked up
1224 „50Ns-1 Pickup“ 50Ns-1 Element picked up
1227 „51Ns Pickup“ 51Ns Element picked up
6823 „48 pickup“ Motor starting supervision pickup 48
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