Schweitzer Engineering Laboratories SEL-421-4 - Figure 5.94 POTT Logic Diagram

5.130
SEL-421 Relay Instruction Manual Date Code 20171021
Protection Functions
Permissive Overreaching Transfer Tripping Scheme
Figure 5.94 POTT Logic Diagram
0
Z3RBD
0
EBLKD
ETDPU
0
0
EDURD
Reset
0
1/8
CYC
1/8
CYC
ETDPU + EDURD + 1 CYCLE
0
0
—
+
—
+
—
+
—
+
Z3RB KEY KEYD EKEY ECTT WFC
Relay
Word
Bits
ILOP
Z3P
Z3G
67G3
67Q3
3PO
ELOP := Y1
TRCOMMD
COMZDTC
TRCOMM
Relay
Word
Bits
PT
EPO := 52
3PT
VAB
VBC VCA
27PPW := 80
3 • VO
59NW := 5
Relay
Word
Bit
Relay
Word
Bits
Relay
Word
Bits
SELOGIC
Setting Setting Setting
EBLKD := OFF
ETDPU := OFF
Settings
Setting
Settings
EWFC := Y, SP
—
+
VA
27AWI
—
+
27BWI
VB
—
+
27CWI
VC
27PWI := 47
Setting