Date Code 20170927 Instruction Manual SEL-751 Relay
Section 10
Analyzing Events
Overview
The SEL-751 Feeder Protection Relay provides several tools (listed below) to
analyze the cause of relay operations. Use these tools to help diagnose the
cause of the relay operation and more quickly restore the protected equipment
to service.
➤ Event Reporting
➢ Event Summary Reports
➢ Event History Reports
➢ Event Reports
➤ Sequential Events Recorder Report
➢ Resolution: 1 ms
➢ Accuracy: ±1/4 cycle
All reports are stored in nonvolatile memory, ensuring that a loss of power to
the SEL-751 does not result in lost data. The SEL-751 offers four styles of
event reports: Standard ASCII (EVE) reports, Compressed ASCII (CEV)
reports, Binary COMTRADE reports, and Sequential Event Recorder (SER)
reports.
Event Reporting
Analyze events with the following event reporting functions:
➤ Event Summaries—Enable automatic messaging to allow the
relay to send event summaries out a serial port when port
setting AUTO := Y. A summary provides a quick overview of
an event. You can also retrieve the summaries by using the
SUMMARY command.
➤ Event History—The relay keeps an index of stored nonvolatile
event reports. Use the HISTORY command to obtain this
index. The index includes some of the event summary
information so that you can identify and retrieve the
appropriate event report.
➤ Event Reports—These detailed reports are stored in nonvolatile
memory for later retrieval and detailed analysis.
Each time an event occurs, a new summary, history record, and report are
created. Event report information includes:
➤ Date and time of the event
➤ Individual sample analog inputs (currents and voltages)
➤ Digital states of selected Relay Word bits (listed in Table K.1)
NOTE: Arc-flash sensor light
values and frequency are available
only in Compressed ASCII event
reports (CEV or CEV
R commands)
NOTE: Models without voltage
inputs will not show voltage values in
the event reports.
To Next Page
Loading...
