701 Motor Protection Relay Date Code 20010719
Event Analysis
Event Reports
9.12
Filtered & Unfiltered Event Reports
The SEL-701 Relay samples the basic power system measurands (ac current and
ac voltage) 16 times per power system cycle. The relay filters the measurands to
remove transient signals. Four times per cycle the relay operates on the filtered values
and reports them in the event report.
To view the raw inputs to the relay, use the unfiltered event report retrieved using
the serial port command EVENT n R. Use the unfiltered event reports to observe:
Power system harmonics on current and voltage channels.
Decaying dc offset during fault conditions on IA, IB, or IC.
Raw event reports display one extra cycle of data at the beginning of the report.
Resetting the Event Report Buffer
The HISTORY R command clears the event summaries and corresponding event
reports from nonvolatile memory. See Section 6: ASCII Serial Port Operation for more
information on the HISTORY command.
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