![Schweitzer Engineering Laboratories SEL-421-4 Instruction Manual Download Page 234](http://html.mh-extra.com/html/schweitzer-engineering-laboratories/sel-421-4/sel-421-4_instruction-manual_1216726234.webp)
5.74
SEL-421 Relay
Instruction Manual
Date Code 20171021
Protection Functions
Mho Ground-Distance Elements
Figure 5.57
Zone 1 Mho Ground-Distance Element Logic Diagram
—
+
—
+
y
Word
Bits
Relay
Word
Bits
Relay
Word
Bit
Relay
Word
Bits
32SPOF
CVTBL
MAG1
MBG1
Z1G
MCG1
XAG1
XBG1
XCG1
32GF
IAL
IGL
mAGF < Z1MG
FSA
SPO
SPOA
OSB1
OSBA
3PO
67Q1T
ILOP
VPOLV
SERCA
0.1 • I
NOM
mAGF A-Phase-to-Ground
Mho Distance Calculation
A-Phase Mho Ground Distance Logic
B- and C-Phase Logic is Similar
Z50G1
(setting)
Summary of Contents for SEL-421-4
Page 6: ...This page intentionally left blank ...
Page 14: ...This page intentionally left blank ...
Page 30: ...This page intentionally left blank ...
Page 104: ...This page intentionally left blank ...
Page 128: ...This page intentionally left blank ...
Page 536: ...This page intentionally left blank ...
Page 584: ...This page intentionally left blank ...
Page 616: ...This page intentionally left blank ...
Page 696: ...This page intentionally left blank ...
Page 750: ...This page intentionally left blank ...
Page 755: ...Instruction Manual PM400 01 NB SEL 400 Series Relays Instruction Manual 20171006 ...
Page 776: ...This page intentionally left blank ...
Page 932: ...This page intentionally left blank ...
Page 976: ...This page intentionally left blank ...
Page 1024: ...This page intentionally left blank ...
Page 1038: ...This page intentionally left blank ...
Page 1064: ...This page intentionally left blank ...
Page 1128: ...This page intentionally left blank ...
Page 1206: ...This page intentionally left blank ...
Page 1316: ...This page intentionally left blank ...
Page 1350: ...This page intentionally left blank ...
Page 1464: ...This page intentionally left blank ...
Page 1468: ...This page intentionally left blank ...
Page 1492: ...This page intentionally left blank ...
Page 1518: ...This page intentionally left blank ...