Schweitzer Engineering Laboratories SEL-421-4 - Page 454

6.118
SEL-421 Relay Instruction Manual Date Code 20171021
Protection Applications Examples
EHV Parallel 230 kV Underground Cables Example
Selectable Operating Quantity Inverse-Time Overcurrent Element 1 (Group)
51S1O 51S1 Op. Qty (IAn, IBn, ICn, IMAXn, I1L, 3I2L,
3I0n)
a
3I2L
51S1P 51S1 O/C Pickup (0.25–16 A secondary) 1.00
51S1C 51S1 Inverse Time O/C Curve (U1–U5) U3
51S1TD 51S1 Inverse Time O/C Time Dial (0.50–15) 3.72
51S1RS 51S1 Inverse Time O/C EM Reset (Y, N) Y
51S1TC 51S1 Torque Control (SEL
OGIC Equation) 32GF
Zone/Level Direction (Group)
DIR3 Zone/Level 3 Directional Control (F, R) R
Directional Control (Group)
ORDER Ground Dir. Element Priority (combine Q, V, I) Q
Pole-Open Detection (Group)
EPO Pole Open Detection (52, V) 52
SPOD Single Pole Open Dropout Delay (0.000–60 cycles) 0.500
3POD Three Pole Open Dropout Delay (0.000–60 cycles) 0.500
POTT Trip Scheme (Group)
Z3RBD Zone 3 Reverse Block Time Delay (0.000–16000
cycles)
5.000
EBLKD Echo Block Time Delay (OFF, 0.000–16000
cycles)
10.000
ETDPU Echo Time Delay Pickup (OFF, 0.000–16000
cycles)
2.000
EDURD Echo Duration Time Delay (0.000–16000 cycles) 4.000
EWFC Weak Infeed Trip (Y, N, SP) N
PT1 General Permissive Trip Received
(SEL
OGIC Equation)
IN103
Trip Logic (Group)
TR Trip (SELOGIC Equation) Z1T OR Z2T OR 51S1T
TRCOMM Communications-Assisted Trip
(SEL
OGIC Equation)
Z2P OR 67Q2
TRCOMMD Dir. Element Comms.-Assisted Trip
(SEL
OGIC Equation)
NA
TRSOTF Switch-Onto-Fault Trip (SEL
OGIC Equation) Z2P OR Z2G OR 50P1
DTA Direct Transfer Trip A-Phase (SEL
OGIC Equation) NA
DTB Direct Transfer Trip B-Phase (SEL
OGIC Equation) NA
DTC Direct Transfer Trip C-Phase (SEL
OGIC Equation) NA
BK1MTR Manual Trip–Breaker 1 (SEL
OGIC Equation) OC1 OR PB8_PUL
ULTR Unlatch Trip (SEL
OGIC Equation) TRGTR
ULMTR1 Unlatch Manual Trip–Breaker 1
(SEL
OGIC Equation)
NOT (52AA1 AND
52AB1 AND 52AC1)
TOPD Trip During Open Pole Time Delay
(2.000–8000 cycles)
2.000
TULO Trip Unlatch Option (1, 2, 3, 4) 3
Table 6.31 Settings for 230 kV Parallel Cables Example (Sheet 4 of 5)
Setting Prompt Entry