9.9
Date Code 20080918 Instruction Manual SEL-749M Relay
Analyzing Events
Event Reporting
Other figures help in understanding the information available in the event
report current columns:
Figure 9.4: shows how event report current column data relate to the
actual sampled current waveform and rms current values.
Figure 9.5: shows how event report current column data can be converted
to phasor rms current values.
Example 15-Cycle
Event Report
The following example of a standard 15-cycle event report in Figure 9.3 also
corresponds to the example SER report in Figure 9.6. The circled numbers in
Figure 9.3 correspond to the SER row numbers in Figure 9.6. The row
explanations appear in Table 9.4.
In Figure 9.3, an arrow (
>) in the column following the VCA column would
identify the “trigger” row. This is the row that corresponds to the Date and
Time values at the top of the event report.
The asterisk (
*) in the column following the VCA column identifies the row
with the maximum phase current. The maximum phase current is calculated
from the row identified with the asterisk and the row one quarter-cycle
previous (see Figure 9.4 and Figure 9.5). These currents are listed at the end
of the event report in the event summary. If the trigger row (
>) and the
maximum phase current row (
*) are the same row, the * symbol takes
precedence, as is the case in Figure 9.3.
Courtesy of NationalSwitchgear.com
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