4.126
SEL-700G Relay
Instruction Manual
Date Code 20170814
Protection and Logic Functions
Group Settings (SET Command)
ORDER—Ground Directional Element Priority Setting.
Setting ORDER
can be set with the elements listed and defined in Table 4.27, subject to the
setting combination constraints in Table 4.28 and Table 4.29. Table 4.29 lists
the ground directional element availability resulting from the voltage
transformer connections.
The order in which the directional elements are listed in setting ORDER
determines the priority in which these elements operate to provide Best
Choice Ground Directional Element logic control.
For example, if setting:
ORDERY := QV
then the first listed directional element (Q = negative-sequence voltage-
polarized directional element; see Figure 4.77) is the first priority directional
element to provide directional control for the residual-ground overcurrent elements.
If the negative-sequence voltage-polarized directional element is not operable
(that is, it does not have sufficient operating quantity as indicated by its
internal enable, DIRQGE, not being asserted; see Figure 4.74), then the
second listed directional element (V = zero-sequence voltage-polarized
directional element; see Figure 4.78) provides directional control for the
residual-ground overcurrent elements.
If the zero-sequence voltage-polarized directional element is not operable
(that is, it does not have sufficient operating quantity as indicated by its
internal enable, DIRVE, not being asserted (see Figure 4.72), then no
directional control is available. The residual-ground overcurrent elements do
not operate, even though these elements are designated with the DIRn
(n = 1, 2) settings to be directionally controlled (see Figure 4.83).
Another example, if setting:
ORDERX := V
then the zero-sequence voltage-polarized directional element (see
Figure 4.78) provides directional control for the residual-ground overcurrent
elements at all times (assuming it has sufficient operating quantity). If there is
not sufficient operating quantity during an event (that is, internal enable
DIRVE is not asserted; see Figure 4.75), then no directional control is
available. The residual-ground overcurrent elements do not operate, even
though these elements are designated with the DIRn (n = 1, 2) settings to be
directionally controlled (see Figure 4.83).
Another example, if setting:
ORDERX := U
then the zero-sequence voltage-polarized directional element (see
Figure 4.80) provides directional control for the neutral-ground overcurrent
elements at all times (assuming it has sufficient operating quantity). Note that
choice U cannot be combined with the rest, V, Q, or I. If there is not sufficient
operating quantity during an event (that is, internal enable DIRNE is not
asserted; see Figure 4.76), then no directional control is available. The
neutral-ground overcurrent elements do not operate, even though these
elements are designated with the DIRn (n = 1, 2) settings to be directionally
controlled (see Figure 4.84). Note that ORDERX cannot be set to U if EDIR is
set to AUTO.
Summary of Contents for SEL-700G Series
Page 14: ...This page intentionally left blank ...
Page 22: ...This page intentionally left blank ...
Page 32: ...This page intentionally left blank ...
Page 52: ...This page intentionally left blank ...
Page 106: ...This page intentionally left blank ...
Page 510: ...This page intentionally left blank ...
Page 560: ...This page intentionally left blank ...
Page 578: ...This page intentionally left blank ...
Page 588: ...This page intentionally left blank ...
Page 604: ...This page intentionally left blank ...
Page 634: ...This page intentionally left blank ...
Page 738: ...This page intentionally left blank ...
Page 802: ...This page intentionally left blank ...