Schweitzer Engineering Laboratories SEL-421-4 - Figure 5.76 Negative-Sequence Instantaneous;Directional Overcurrent Elements; Inverse-Time Overcurrent Elements

5.99
Date Code 20171021 Instruction Manual SEL-421 Relay
Protection Functions
Inverse-Time Overcurrent Elements
Inverse-Time Overcurrent Elements
The SEL-421 provides three selectable operating quantity inverse-time overcur-
rent elements. Ten different time-overcurrent characteristics (5 U.S. and 5 IEC
curves) are available.
Each time-overcurrent element can be configured to operate on the line current
(i.e., IW terminal current or the sum of the IW and IX terminal currents) depend-
ing upon setting LINEI; or circuit breaker operating quantities, with the terminal
source depending upon settings BK1I and BK2I.
Symmetrical component current quantities are available only for the line-current
source. Tab le 5.61 defines the available setting choices for operating quantities
and the corresponding analog quantity name as found in Section 12: Analog
Quantities.
Figure 5.76 Negative-Sequence Instantaneous/Directional Overcurrent Elements
67Q1D
0
—
+
50Q1
67Q1
67Q1T
3I2L
50Q1P
(Setting)
67Q1TC
(SEL
OGIC
Setting)
32QF
(Relay
Word Bit)
Relay
Word
Bits
67Q2D
0
—
+
50Q2
67Q2
67Q2T
50Q2P
(Setting)
67Q2TC
(SEL
OGIC
Setting)
32QF
(Relay
Word Bit)
67Q3D
0
—
+
50Q3
67Q3
67Q3T
50Q3P
(Setting)
DIR3 := F
(Setting)
67Q3TC
(SEL
OGIC
Setting)
32QF
(Relay
Word Bit)
32QR
(Relay
Word Bit)
67Q4D
0
—
+
50Q4
67Q4
67Q4T
50Q4P
(Setting)
DIR4 := F
(Setting)
67Q4TC
(SEL
OGIC
Setting)
32QF
(Relay
Word Bit)
32QR
(Relay
Word Bit)