Schweitzer Engineering Laboratories SEL-787 - Table 4.34 Setting Group Selection; Table 4.35 Breaker Failure Setting

4.84
SEL-787 Relay Instruction Manual Date Code 20081022
Protection and Logic Functions
Global Settings (SET G Command)
EXAMPLE 4.5 Setting MPTXxx With a Specified Location of Analog
Quantity
MPTX01 := THE LOAD CURRENT IS %.2f AMPERES
MPAQ01 value = 157.44
Formatted message out when triggered: THE LOAD CURRENT IS
157.44 AMPERES
MPTX01 := THE LOAD CURRENT IS %d AMPERES
MPAQ01 value = 157.44
Formatted message out when triggered: THE LOAD CURRENT IS 157
AMPERES
Group Selection
The TGR setting defines the amount of time that the SS1, SS2, SS3, and SS4
SEL
OGIC control equation logic results must remain stable before the relay
enables a new setting group. Typically, a one-second delay is sufficient.
SS1, SS2, SS3, and SS4 are SEL
OGIC control equations that help define when
setting Group 1, 2, 3, and 4 are active. With the settings shown above, SS1 is
set equal to logical 1, thus setting Group 1 always is active.
Synchrophasor
Measurement
The SEL-787 Transformer Protection Relay provides Phasor Measurement
Control Unit (PMCU) capabilities when connected to an IRIG-B time source.
See Appendix H: Synchrophasors for description and Table H.1 for the
settings.
Breaker Failure
Setting
The SEL-787 provides flexible breaker failure logic (see Figure 4.54) for two
breakers. In the default breaker failure logic, assertion of trip Relay Word bits
associated with a breaker starts a BFD timer if the sum of positive and
negative-sequence breaker current is above 0.02 • I
NOM
. If the current remains
above the threshold for BFD delay setting, Relay Word bit BFT will assert.
Use the BFT to operate an output relay to trip appropriate backup breakers.
Table 4.34 Setting Group Selection
Setting Prompt Setting Range
Setting Name :=
Facto ry Defa ul t
GRP CHG DELAY 0–400 sec TGR := 3
SELECT GROUP1 SEL
OGIC SS1 := 1
SELECT GROUP2 SEL
OGIC SS2 := 0
SELECT GROUP3 SEL
OGIC SS3 := 0
SELECT GROUP4 SEL
OGIC SS4 := 0
Table 4.35 Breaker Failure Setting
Setting Prompt Setting Range Setting Name := Factory Default
52A INTERLOCK Y, N 52ABF := N
BRKR1 FAIL DELAY 0.00–2.00 sec BFD1 := 0.50
BRKR1 FAIL INIT SEL
OGIC BFI1 := R_TRIG TRIP1 OR
R_TRIG TRIPXFMR
BRKR2 FAIL DELAY 0.00-2.00 sec BFD2 := 0.50
BRKR2 FAIL INIT SEL
OGIC BFI2 := R_TRIG TRIP2 OR
R_TRIG TRIPXFMR