4.12
SEL-351A Relay Instruction Manual Date Code 20080213
Loss-of-Potential, Load Encroachment, and Directional Element Logic
Directional Control for Neutral-Ground and Residual-Ground Overcurrent Elements (Not in SEL-351A-1)
Table 4.2 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
(not dependent on
neutral channel [IN])
Q 32QGE
QV 32QGE 32VE
V 32VE
VQ 32VE 32QGE
I 32IE Additional setting
combinations for
models with a 1 A or
5 A nominal neutral
channel (IN)
IQ 32IE 32QGE
IQV 32IE 32QGE 32VE
IV 32IE 32VE
IVQ 32IE 32VE 32QGE
QI 32QGE 32IE
QIV 32QGE 32IE 32VE
QVI 32QGE 32VE 32IE
VI 32VE 32IE
VIQ 32VE 32IE 32QGE
VQI 32VE 32QGE 32IE
VS 32VE 32NE (Low-impedance) Additional setting
combinations for
models with a 0.2 A
nominal neutral
channel (IN)
a
VQS 32VE 32QGE 32NE (Low-impedance)
QVS 32QGE 32VE 32NE (Low-impedance)
P 32NE (Petersen Coil)
QP 32QGE 32NE (Petersen Coil)
QVP 32QGE 32VE 32NE (Petersen Coil)
VP 32VE 32NE (Petersen Coil)
VQP 32VE 32QGE 32NE (Petersen Coil)
U 32NE (Ungrounded/
High-Impedance)
a
S, P, and U are mutually exclusive and are the last (or only) listed choice for the ORDER setting.
Courtesy of NationalSwitchgear.com
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