Schweitzer Engineering Laboratories SEL-751 - Table 4.20 Best Choice Ground Directional Element Logic

4.29
Date Code 20170927 Instruction Manual SEL-751 Relay
Protection and Logic Functions
Group Settings (SET Command)
Table 4.20 Best Choice Ground Directional Element Logic
ORDER
Setting
Combinations
Resultant ground directional
element preference (indicated below with
corresponding internal enables;
run element that corresponds to highest
choice internal enable that is asserted;
system grounding in parentheses)
ORDER Setting
Combination
Availability
1st Choice 2nd Choice 3rd Choice
OFF No ground directional elements enabled All models
(independent on
neutral channel
[IN])
QDIRQGE
QV DIRQGE DIRVE
VDIRVE
VQ DIRVE DIRQGE
I DIRIE Additional
setting
combinations for
models with a
1A or 5 A
nominal neutral
channel (IN)
IQ DIRIE DIRQGE
IQV DIRIE DIRQGE DIRVE
IV DIRIE DIRVE
IVQ DIRIE DIRVE DIRQGE
QI DIRQGE DIRIE
QIV DIRQGE DIRIE DIRVE
QVI DIRQGE DIRVE DIRIE
VI DIRVE DIRIE
VIQ DIRVE DIRIE DIRQGE
VQI DIRVE DIRQGE DIRIE
VS DIRVE DIRNE (Low-
impedance)
Additional
setting
combinations for
models with a
0.2 A nominal
neutral channel
(IN)
a
a
S, P, and U are mutually exclusive and are the last (or only) listed choice for the order setting.
VQS DIRVE DIRQGE DIRNE (Low-
impedance)
QVS DIRQGE DIRVE DIRNE (Low-
impedance)
PDIRNE
(Petersen coil)
QP DIRQGE DIRNE
(Petersen coil)
QVP DIRQGE DIRVE DIRNE
(Petersen coil)
VP DIRVE DIRNE
(Petersen coil)
VQP DIRVE DIRQGE DIRNE
(Petersen coil)
UDIRNE
(Ungrounded/
high-imped-
ance)