Schweitzer Engineering Laboratories SEL-351-5, Instruction Manual

Page: 539 / 706

12.39
Date Code 20070117
Instruction Manual SEL-351-5, -6, -7 Relay
Standard Event Reports, Sag/Swell/Interruption Report, and SER
Sag/Swell/Interruption (SSI) Report (Available in Firmware Version 7)
Clearing the SSI
Report
Clear the SSI report from nonvolatile memory with the SSI C command as
shown in the following example:
=> SSI C <Enter>
Clear the Voltage Sag/Swell/Interruption buffer
Are you sure (Y/N)?
Y <Enter>
Clearing Complete
The SSI C command is available in any setting group and on any serial port.
If the SSI C command is issued on one serial port while another serial port is
being used to display an SSI report, the clearing action will terminate the SSI
report retrieval.
If maximum SSI recorder capacity is desired, the SSI Report should be
checked periodically, with the data captured to a computer file using a
terminal emulation program. Once the data has been viewed or captured, use
the
SSI C command to clear the SSI recorder.
Clearing the SSI Recorder makes it easier to tell if any new disturbances have
been recorded, and it also allows the SSI Archive to record the maximum of
7710 entries. If more than 7710 entries occur, the oldest half of the SSI archive
will be erased to make room for the new entries. The most recent 3855 entries
are always available.
Triggering the SSI
Recorder
Manually force the SSI Recorder to trigger using the SSI T command as
shown in the following example:
=> SSI T <Enter>
Triggered
The SSI T command is only available if group setting ESSI = Y in the active
setting group.
If an SSI T command is issued when setting ESSI = N, the relay will respond
as follows:
Command is not available
If an SSI T command is issued before Vbase has initialized, the relay will
respond as follows:
Did Not Trigger
See Vbase Initialization on page 3.54 for details on the initializing conditions.
The SSI T command is useful for testing, because it provides an easy method
of creating some SSI Report entries without the need to remove voltage
signals or connect a test set, providing Vbase has already been initialized.
Resetting the SSI
Recorder Logic
During relay commissioning or test procedures, the SSI recorder may
memorize the Vbase quantity when test voltages or settings are applied. This
could cause the recorder to declare a false SAG or SWELL condition when
normal system voltages are applied. Reset the SSI Recorder logic and clear the
Vbase value by issuing the
SSI R command as shown in the following
example: