12.3
Date Code 20080213 Instruction Manual SEL-351A Relay
Standard Event Reports and SER
Standard 15/30-Cycle Event Reports
Programmable SELOGIC Control Equation Setting ER
The programmable SELOGIC control equation event report trigger setting ER
is set to trigger standard event reports for conditions other than trip conditions.
When setting ER sees a logical 0 to logical 1 transition, it generates an event
report (if the SEL-351A is not already generating a report that encompasses
the new transition). The factory setting is:
ER = /51P + /51G + /OUT103
The elements in this example setting are:
➤ 51P Maximum phase current above pickup setting 51PP for
phase time-overcurrent element 51PT (see Figure 3.14).
➤ 51G Residual-ground current above pickup setting 51GP for
residual-ground time-overcurrent element 51GT (see
Figure 3.19).
➤ OUT103 Output contact OUT103 is set as a breaker failure trip
output (see Figure 7.25).
Note the rising-edge operator / in front of each of these elements. See
Appendix G: Setting SEL
OGIC Control Equations for more information on
rising-edge operators and SEL
OGIC control equations in general.
Rising-edge operators are especially useful in generating an event report at
fault inception and then generating another later if a breaker failure condition
occurs. For example, at the inception of a ground fault, pickup indicator 51G
asserts and an event report is generated:
ER = ... + /51G + ... = logical 1 (for one processing interval)
Even though the 51G pickup indicator will remain asserted for the duration of
the ground fault, the rising-edge operator / in front of 51G (/51G) causes
setting ER to be asserted for only one processing interval.
If the fault is not interrupted after the relay trips, then the relay outputs a
breaker failure trip with output contact OUT103 and another event report is
generated:
ER = ... + /OUT103 = logical 1 (for one processing interval)
As stated earlier, the 51G pickup indicator is still asserted at the time of
breaker failure trip, but the rising-edge operators allow each individual action
to generate a separate event report.
Falling-edge operators \ are also used to generate event reports. See
Figure G.2 for more information on falling-edge operators.
TRI (Trigger Event Report) and PUL (Pulse Output Contact) Commands
The sole function of the TRI serial port command is to generate standard
event reports, primarily for testing purposes.
The PUL command asserts the output contacts for testing purposes or for
remote control. If output contact OUT101–OUT107 asserts via the PUL command,
the relay triggers a standard event report. The PUL command is available at
the serial port and the relay front-panel {CNTRL} pushbutton.
See Section 10: Serial Port Communications and Commands and Section 11:
Front-Panel Interface (Only on Models With LCD) (Figure 11.3) for more
information on the TRI (Trigger Event Report) and PUL (Pulse Output
Contact) commands.
Courtesy of NationalSwitchgear.com
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