GE LPS-D, Инструкция по эксплуатации

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GE Power Management LPS-D Line Protection System 2-
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2 CALCULATION OF SETTINGS 2.2 GENERAL SETTINGS
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2.2.3 OSCILLOGRAPHY
301: NUMFAULTS - Number Of Faults To Be Captured
NUMFAULTS selects the maximum number of oscillography "storage events" (faults) that may be stored in
memory. When the maximum number are stored in memory, the oscillography data associated with a subse-
quent storage event will overwrite the data from the oldest event.
This setting allows the user to apportion a fixed amount of memory into different sized blocks for oscillography
storage. Table 2–4: OSCILLOGRAPHY CYCLES PER STORAGE EVENT shows the total number of oscillog-
raphy cycles allowed per storage event as a function of the NUMFAULTS setting.
302: PREFAULT - Number Of Pre-Fault Cycles To Capture
PREFAULT selects the number of pre-fault or pre-trigger cycles to be stored in each oscillography record. It
can be set over the range from 1 to 8. NUMFAULTS, as explained above, determines the total number of
cycles per oscillography record, and PREFAULT determines how many of these will be pre-fault cycles.
303: SPLITREC - Split Oscillography Record For Long Duration Faults
The LPS-D allows a pre-defined number of oscillographic records to be captured per the NUMFAULTS setting
described above. Each record is a specific number of cycles long as determined by this setting. If a fault occurs
that is greater in length than the number of cycles set to be captured, the SPLITREC setting will allow the
record to be split so that the beginning and the end of the fault can be captured. Note that SPLITREC does not
affect the number of pre-fault cycles that are captured as determined by the PREFAULT setting. SPLITREC
applies only the fault record exclusive of the pre-fault cycles. SPLITREC is set as a percentage with a range of
0 to 100 percent, and splits the record so that the end of the record is equal to the SPLITREC percentage and
the beginning of the record is equal to (100 – SPLITREC). For example, assume that NUMFAULTS is set to 4
and PREFAULT is set to 4. This means that the record will capture 4 cycles of pre-fault data and 28 cycles of
fault data. The LPS-D samples at 64 times per cycle, therefore, 2048 samples (64 x 32) of fault data will be
captured. Further assume that SPLITREC is set to 30%. If the fault lasts longer than 32 cycles (2048 samples),
then 28 cycles (1792 samples) of the oscillographic record will be split and the display will show 8.4 cycles
(538 samples) at the end and 23.6 cycles (1510 samples) at the beginning. If the fault is less than the set num-
ber of cycles then SPLITREC has no effect and the total fault record will be displayed.
Use a setting for SPLITREC that will display the information most desired in a long duration fault. (more at the
beginning and less at the end or vice versa).
Table 2–4: OSCILLOGRAPHY CYCLES PER STORAGE EVENT
NUMFAULTS STORAGE CYCLES
6 72
12 36
24 18
36 12