Schweitzer Engineering Laboratories SEL-311L, Instruction Manual, Page: 96 / 734

3-42 Line Current Differential, Distance, Out-of-Step, Overcurrent, Date Code 20011112
Voltage, Synchronism Check, and Frequency Elements
SEL-311L Instruction Manual
|IA|
50L2
(Advanced Setting)
From Figure 4.12 32GF
_
+
_
+
|IG|
50GZ2
(Advanced Setting)
See Note 1 mAG < Z2MG
M311L120
FSA
From Figure 5.5 3PO
From Figure 4.1 ILOP
VPOLV
MAG2
MBG2
MCG2
XAG2
XBG2
XCG2
Z2G
Zone 2 A-Phase Mho Ground Distance Logic.
B and C Phase Are Similar.
Note 1: mAG = A-Phase to Ground Distance Calculation
Z2MG = Zone 2 Distance Setting
Relay
Word
Bits
Relay
Word
Bit
Relay
Word
Bits
(unless
noted)
Figure 3.33: Zone 2 Mho Ground Distance Logic
DIR n = F (Setting)
From Figure 4.12 32GF
|IA|
50L
n
(Advanced Setting)
mAG < Z nMG
FSA
From Figure 5.5 3PO
From Figure 4.1 ILOP
VPOLV
_
+
Zone 3 and 4 A-Phase Mho Ground Distance Logic.
B- and C-Phase Logic Is Similar.
Note 1: mAG = A-Phase to Ground Distance Calculation
Z
nMG = Zone n Distance Setting
n = 3 for Zone 3
n = 4 for Zone 4
DWG: M311L121
From Figure 4.12 32GR
_
+
|IG|
50GZ
n
(Advanced Setting)
MAG n
MBG n
MCG
n
XAG n
XBG n
XCG n
Z nG
mAG > -Z
nMG
See Note 1
Relay
Word
Bit
Relay
Word
Bits
Relay
Word
Bits
(unless
noted)
Figure 3.34: Zones 3 and 4 Mho Ground Distance Logic