Schweitzer Engineering Laboratories SEL-351-5, Instruction Manual

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4.11
Date Code 20070117
Instruction Manual SEL-351-5, -6, -7 Relay
Loss-of-Potential, Load Encroachment, and Directional Element Logic
Directional Control for Neutral Ground and Residual Ground Overcurrent Elements
q Figure 4.8 ; w Figure 4.14 ; e Figure 4.15 ; r Figure 4.16 ; t Figure 4.17 ; y Figure 4.18 ; u Figure 3.19 ; i Figure 3.10 ;
o Figure 3.18 ; a Figure 3.8 .
Figure 4.5 General Logic Flow of Directional Control for Neutral Ground and Residual Ground Overcurrent
Elements (Ungrounded/High-Impedance Grounded Systems; ORDER = U)
q
F32N/
R32N
r y
32NE
ORDER = U
50NF/
50NR
to Neutral Ground Time-
Overcurrent Elements
(
o )
to Neutral Ground
Inst./Def.-Time
Overcurrent Elements
(
a )
Level 1
32NF/
32NR
Ungrounded/
High-
Impedance
w
e
32GF/
32GR
t
Level 1
Level 2
Level 3
Level 4
to Residual Ground
Inst./Def.-Time
Overcurrent Elements
(
i )
Level 2
Level 3
Level 4
to Residual Ground Time-
Overcurrent Elements
(
u )
Enable Directional
Elements with
Setting ORDER
Internal
Enables
Relay Word
Bit
Outputs
Directional
Elements
Relay Word
Bit
Outputs
Relay Word
Bit
Outputs
Direction
Forward/
Reverse Logic
Directional
Control
Directional
Element
Routing
Table 4.1 Available Ground Directional Elements
ORDER
Setting
Choices
Corresponding
Ground
Directional
Element (and
System
Grounding)
Corresponding
Internal
Enables (and
System
Grounding)
Corresponding
Figures
Availability
Q Negative-
sequence
voltage-polarized
32QGE Figure 4.6 ,
Figure 4.9
All models (not
dependent on
neutral channel
[IN])
V Zero-sequence
voltage-polarized
32VE Figure 4.7 ,
Figure 4.10
I Channel IN
current polarized
32IE Figure 2.13 ,
Figure 4.7 ,
Figure 4.11
Models with a 1
A or 5 A nominal
neutral channel
(IN)
S Zero-sequence
voltage-polar-
ized (Low-
impedance)
32NE (Low-
impedance)
Figure 2.18 ,
Figure 4.8 ,
Figure 4.12
Models with a
0.2 A nominal
neutral channel
(IN)
P Wattmetric and
incremental
conductance
(Petersen Coil)
32NE
(Petersen Coil)
Figure 2.19 ,
Figure 4.8 ,
Figure 4.13
U Zero-sequence
voltage-
polarized
(Ungrounded/
High-Impedance)
32NE
(Ungrounded/
High-Impedance)
Figure 2.18 ,
Figure 2.20 ,
Figure 2.21 ,
Figure 4.8 ,
Figure 4.14
NOTE:
S, P, and U are mutually
exclusive—they cannot be listed
together in the ORDER setting.
NOTE:
The neutral channel (IN) can
also be ordered as a 0.05 A nominal
neutral channel. Such a rated neutral
channel provides no special
directional element options, like those
listed above. The 0.05 A nominal
neutral channel is a legacy
nondirectional sensitive earth fault
(SEF) option (a 0.2 A nominal neutral
channel can provide the same SEF
function and more). See
Figure 3.8 ,
Figure 3.9 , and Figure 3.18 and
accompanying setting ranges
explanation.