Schweitzer Engineering Laboratories SEL-787 - Figure 4.44 Trip Logic

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Date Code 20081022 Instruction Manual SEL-787 Relay
Protection and Logic Functions
Trip/Close Logic
Figure 4.44 Trip Logic
TDURD Minimum Trip Time
This timer establishes the minimum time duration for which the TRIP Relay
Word bits assert. This is a rising-edge initiated timer.
Trips initiated by TRm (m = 1, 2, XFMR) Relay Word bits (includes OPEN
command from front-panel and serial ports) are maintained for at least the
duration of the minimum trip duration time (TDURD) setting.
TR Trip Conditions SELOGIC Control Equations
There are three trip logic equations within the SEL-787. They are designed to
operate when
SELOGIC control equation trip variable setting TRm is asserted
(m = 1, 2, XFMR), and to unlatch when
SELOGIC control equation setting
0
TDURD
Serial Port
Command TAR R
TARGET RESET
Pushbutton
TRGTR
Reset
TRIP LED
RWB
TRIP1
Trigger
Events
Unlatch Trip
Comm.
Target Reset
RSTTRGT
ULTRIP1
TR1
Relay
Word
Bits
SELOGIC
Settings
0
TDURD
RWB
TRIP2
Trigger
Events
Unlatch Trip
ULTRIP2
TR2
0
TDURD
RWB
TRIPXFMR
Trigger
Events
Unlatch Trip
ULTRXFMR
TRXFMR
TRIP1
TRIP2
TRIXFMR
RWB
TRIP