Schweitzer Engineering Laboratories SEL-421-4 - Figure 5.63 Zone 1 Mho Phase-Distance Element Logic Diagram

5.82
SEL-421 Relay Instruction Manual Date Code 20171021
Protection Functions
Mho Phase-Distance Elements
Figure 5.63 shows the Zone 1 phase-distance element logic. The other fault cal-
culations (BC, CA) have similar logic. In Figure 5.63, Output Z1P is the OR
combination of the following Zone 1 elements (ØØ = AB, BC, CA):
➤ Conventional mho elements (MØØ1)
➤ Conventional quadrilateral elements (XØØ1)
Figure 5.63 Zone 1 Mho Phase-Distance Element Logic Diagram
—
+
Relay
Word
Bits
Relay
Word
Bits
Relay
Word
Bits
—
+
—
+
IABLFM
MABDF
mABF
Z1MP
(setting)
F32P
32SPOF
SPOA
67Q1T
SPOB
SPOC
VPOLV
SERCAB
CVTBL
ILOP
OSBA
OSB1
0.1 • I
NOM
MAB1
MBC1
XBC1
XCA1
MCA1
XAB1
Z1P
FSA
FSB
Relay
Word
Bits
M1P
Z50P1
(setting)