U.6.5
Date Code 20090715 User’s Guide SEL-421 Relay
Testing and Troubleshooting
Testing Features and Tools
Event Reports
The relay also generates a filtered-quantities event report in response to faults
or disturbances. Each event report contains information on current and
voltage, relay element states, control inputs, and control outputs. If you are
unsure of the relay response or your test method, the event report provides you
with information on the operating quantities that the relay used at the event
trigger. The relay provides oscillographic displays of the filtered event report
data, which give you a visual tool for testing relay operating quantities. You
can use the serial ports and
ACSELERATOR QuickSet to view event reports.
See Event Reports, Event Summaries, and Event Histories on page A.3.11 for
a complete discussion of event reports.
Event Summary Reports
The relay generates an event summary for each event report; use these event
summaries to quickly verify proper relay operation. With event summaries,
you can quickly compare the reported fault current and voltage magnitudes
and angles against the reported fault location and fault type. If you question
the relay response or your test method, you can obtain the full event report and
the high-resolution oscillographic report for a more detailed analysis. See
Event Summary on page A.3.28 for more information on the event summary.
SER Reports
The relay provides an SER report that time tags changes in relay elements,
control inputs, and control outputs. Use the SER for convenient verification of
the pickup and dropout of any relay element. For a complete discussion of the
SER, see SER (Sequential Events Recorder) on page A.3.34.
Test Commands
TAR Command
Use the TAR command to view the state of relay control inputs, relay outputs,
and relay elements individually during a test. You can see relay targets at the
serial ports, and from the front-panel LCD (see TARGET on page R.9.50 and
Operation and Target LEDs on page U.5.36).
PUL Command
Use the PUL command to test the control output circuits. The specified output
closes if open, or opens if closed. You can use the PUL command at the serial
ports, in the
ACSELERATOR QuickSet HMI, and from the front-panel LCD
(see PULSE on page R.9.37, HMI Meter and Control on page U.3.21, and
Operation and Target LEDs on page U.5.36).
TEST DB Command
Use the TEST DB command for testing the communications card relay
database. The TEST DB command can be used to override any value in the
relay database. Since the relay database provides data to the Ethernet card
interfaces, the TEST DB command can also be used to test the data read
operations of the DNP3 LAN/ WAN or IEC 61850 protocols on an installed
Ethernet card. Use the MAP 1 command and the VIEW1 command to inspect
the relay database (see MAP on page R.9.27). You must be familiar with the
relay database structure to use the TEST DB command effectively; see
Communications Card Database on page R.4.18 for more information.
NOTE: Control Inputs are sampled
16 times per cycle, and then
conditioned by a debounce timer. The
resulting Relay Word bits are
updated 8 times per cycle and are
available in standard event report
files—see Figure 3.1 on page A.3.3.
Courtesy of NationalSwitchgear.com
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