7.2
SEL-551 Relay Instruction Manual Date Code 20110408
Standard Event Reports and SER
Standard 15-Cycle Event Reports
Relay Word Bit TRIP
Relay Word bit TRIP would usually be assigned to an output contact for
tripping a circuit breaker (e.g., SEL
OGIC control equations setting OUT1 =
TRIP). SEL
OGIC Control Equations setting TR controls the assertion of Relay
Word bit TRIP (see Figure 3.13). Any condition that is set to trip in setting TR
(e.g., TR = 51P1T + 51G1T + 50P1*SH0 + LB3) does not have to be entered
in SEL
OGIC control equation settings ER1 or ER2. The assertion of Relay
Word bit TRIP automatically triggers a standard 15-cycle event report.
Programmable SELOGIC Control Equation Settings ER1 and ER2
The programmable SELOGIC control equation settings ER1 and ER2 are set to
trigger standard 15-cycle event reports for conditions other than tripping
conditions already listed in SEL
OGIC control equations setting TR. The
factory settings are:
ER1 = 51P1 + 51G1
ER2 = SV5T + CF
ER1 is factory-set with time-overcurrent element pickups 51P1 and 51G1.
Thus, at the inception of a fault, whichever pickup asserts first will trigger a
standard 15-cycle event report.
ER2 is factory-set with a breaker failure condition (SV5T) and close failure
condition (CF). It is not likely that these two conditions would assert at the
same time. When a breaker failure or close failure condition occurs, a standard
15-cycle event report is triggered.
ER1 and ER2 trigger event reports independently and are rising-edge sensitive
(logical 0 to logical 1 transition). For example, if a line-to-ground fault occurs
and 51G1 asserts first in setting ER1 (logical 0 to logical 1 transition), it will
trigger an event report. If 51G1 remains asserted and then a short time later
51P1 asserts, a second report will not be generated for the assertion of 51P1.
ER1 is already at logical 1 because of the initial assertion of 51G1.
Rising-edge or falling-edge detects can be used in making SEL
OGIC settings.
This is particularly useful in these event report trigger settings ER1 and ER2.
For example, if setting ER1 = /IN2 + …, then every time input IN2 asserts
(logical 0 to logical 1 transition), setting ER1 is effectively pulsed for one-
processing interval. Thus, if input IN2 continues to be asserted (maintained at
logical 1), it has no further effect on setting ER1 and any other Relay Word bit
in setting ER1 is effectively free to operate and be detected by setting ER1.
Most likely, each ORed Relay Word bit in setting ER1 or ER2 would have a
rising-edge or falling-edge detect in front of it.
See Section 3: Relay Elements and Logic for more information on SEL
OGIC
control equations.
TRIGGER and PULSE Serial Port Commands
The sole function of the TRIGGER serial port command is to generate
standard 15-cycle event reports, primarily for testing purposes.
The PULSE serial port command is used to assert the output contacts for
testing purposes or for remote control. If output contact OUT1, OUT2, OUT3, or
OUT4 is asserted with the PULSE command, a standard 15-cycle event report
is also generated.
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