Schweitzer Engineering Laboratories SEL-701, Instruction Manual

Page: 217 / 468

Date Code 20010719
701 Motor Protection Relay
Event Analysis
History Data & Event Summaries
9.5
History Data & Event Summaries
Each time the SEL-701 Relay trips, and in response to other selected conditions,
the relay captures motor current, voltage (if included), RTD (if included), protection
element, contact input, and contact output information. This collection of data is called
an event report and is described in detail in
Event Reports on page 9.7 .
The relay stores the 14 most recent event reports and their summaries in
nonvolatile memory. These reports are numbered 1 through 14, older reports having
higher numbers. When the relay stores a new report, it discards the oldest report if 14
reports are already in memory.
The relay also stores an event summary associated with each event report. Each
event summary contains selected data acquired at the instant the relay tripped or at the
instant the event was triggered if a trip did not occur during the event. Use the summary
data to help discern the cause of relay trip operations before you review the full event
report.
View the present collection of event summaries using the front-panel History Data
menu selection or the serial port HISTORY command. Each event summary contains:
The type of event, from the list of event type strings in Note 4 on
page C.55 in Appendix C: Modbus® RTU Communications Protocol .
The event number, date, and time.
The system frequency.
The % Thermal Capacity used.
The % Unbalance Current.
The magnitudes of the phase, neutral, residual, and negative-sequence
currents.
The temperatures of the hottest winding, bearing, ambient, and other
RTDs, if included.
The magnitudes of the phase-to-phase voltages, if included.
The magnitudes of the real power, reactive power, and power factor, if
voltages are included.
The following table provides a list of event triggering commands and their
equivalent names reported in the Event/History reports. For example, if the event is
stored in response to execution of the serial port
TRIGGER command, the
Event/History report will list the event type as TRIG.