Siemens SIPROTEC 7SS60, Manual

Page: 72 / 134

Functions
5-22
7SS60 Manual
E50417-G1176-C132-A2
5.6 Fault recording
−
Block 74
5.6.1 Function description
The 7SS601 protection system has a fault recording function that stores the
instantaneous values of the differential and the restraint current in a buffer. This
function is available in block
.
The instantaneous values of the measured quantities are sampled every 0.5 ms (50,
60 and 16.7 Hz).
In the event of a fault, the data are stored during a settable period. The available buffer
has a recording capacity of 7.1 s.
Up to 8 fault events can be stored in this buffer. New fault events are always entered
in the fault record buffer. Older records are overwritten by the new data.
The data can be read out to a personal computer via the serial interface, and
processed using the DIGSI / SIGRA software. The measured values are prepared for
a graphical display. In addition, signals are represented as binary traces, e.g. "
%XVEDU
SURWHFWLRQ7ULS
" and "
/RFN2XWVWDWH
".
Part of the fault recording memory in the 7SS601 is buffered against voltage failures.
The buffered portion has a capacity of 5 s. It contains always the most recent fault
events.
A fault event starts with tripping by a protection function and ends with the reset of the
last tripping by a protection function. Fault records in the 7SS601 always cover this
span of time (plus the pre-fault and the post-fault time).
5.6.2 Hints on setting
Times The actual storage time starts with the pre-fault time
735(
( ) that precedes
the reference point and ends when the post-fault time
7326
( ) following the
disappearance of the storage criterion has elapsed. The maximum permissible total
storage time per fault record is set in
70$;
( ). A total of 7.1 s is available
for fault recording.
5.6.3 Overview of parameters
DIGSI
addr.
Parameter Possible settings Default setting Explanation
7410 74-T MAX 0.20 s to 5.00 s 1.50 s Maximum time period of a fault
recording
7411 74 T-PRE 0.05 s to 1.50 s 0.30 s Pre-trigger time for fault recording
7412 74 T-POS 0.05 s to 1.50 s 0.20 s Post-fault time for fault recording