Schweitzer Engineering Laboratories SEL-421-4 - Figure 5.64 Zone 2 Mho Phase-Distance Element Logic Diagram

5.83
Date Code 20171021 Instruction Manual SEL-421 Relay
Protection Functions
Mho Phase-Distance Elements
Figure 5.64 shows the Zone 2 phase-distance element logic. The other fault cal-
culations (BC, CA) have similar logic. In Figure 5.64, Output Z2P is the OR
combination of the following Zone 2 elements (ØØ = AB, BC, CA):
➤ Conventional mho elements (MØØ2)
➤ Conventional quadrilateral elements (XØØ2)
Figure 5.64 Zone 2 Mho Phase-Distance Element Logic Diagram
—
+
Relay
Word
Bits
Relay
Word
Bits
Relay
Word
Bits
—
+
—
+
IABLFM
MABDF
mABF
Z2MP
(setting)
F32P
32SPOF
SPOA
67QUBF
SPOB
FSA
FSB
SPOC
VPOLV
ILOP
OSBA
OSB2
0.1 • I
NOM
MAB2
MBC2
XBC2
XCA2
MCA2
XAB2
Relay
Word
Bit
Z2P
Relay
Word
Bits
M2P