Schweitzer Engineering Laboratories SEL-751 - Figure 4.39 Routing of Directional Elements to Negative-Sequence and Phase Overcurrent Elements; Figure 4.40 Direction Forward;Reverse Logic for Negative-Sequence Overcurrent Elements

4.52
SEL-751 Relay Instruction Manual Date Code 20170927
Protection and Logic Functions
Group Settings (SET Command)
q From Figure 4.73; w from Figure 4.37; e from Figure 4.38;
r to Figure 4.40; t to Figure 4.41.
Figure 4.39 Routing of Directional Elements to Negative-Sequence and
Phase Overcurrent Elements
q From Figure 4.39; w Figure 4.7; e Figure 4.2.
Figure 4.40 Direction Forward/Reverse Logic for Negative-Sequence
Overcurrent Elements
LOP
FDIRQ
RDIRQ
Relay
Word
Bits
DIRPF
(Forward)
DIRQF
(Forward)
DIRPR
(Reverse)
DIRQR
(Reverse)
Setting
EFWDLOP = Y
Loss-of-
Potential
FDIRP
RDIRP
1
2
3
4
5
Level Direction
Settings
DIRQF
DIR1 = F
DIR1 = N
Relay
Word
Bit
Relay
Word
Bit
to Negative-
Sequence
Time-0vercurrent
Element
to Negative-
Sequence
Instantaneous/
Definite-Time
Overcurrent
Elements
VNOM = OFF
Setting
Forward
Forward
DIRQR
Reverse
DIR1 = R
Reverse
DIR2 = F
DIR2 = N
Forward
DIR2 = R
Reverse
DIR3 = F
DIR3 = N
Forward
DIR3 = R
Reverse
DIR4 = F
DIR4 = N
Forward
DIR4 = R
Reverse
1
1
2
3
Directional
Control
Level 1
Q1DIR
Level 2
Q2DIR
Level 3
Q3DIR
Level 4
Q4DIR