I.L. 40-386.3
2-2
(10/94)
is the direction where tripping takes place; the “reverse” reach is then in the forward
line direction.)
(1)
(2)
Z
0L
, Z
1L
=
zero and positive sequence line impedance in relay ohms
Z
CGF
, Z
CGR
=
Zone forward and reverse reach settings in secondary ohms of Z1L, for ph-
G fault (both are in angle PANG)
These units are directionally supervised by FDOG (RDOG for reverse Zone3). Because of in-
ternal clipping of unfaulted phase voltages during phase-ground faults,
use of Zero-sequence
or Dual Polariz (polarization) for DIR TYPE only is recommended when applied to resis-
tance grounded systems; calculation of V2 magnitude and angle is likely to be incorrect in this
application, causing NSEQ polarization to give false directional sense (
see Section 2.4.11).
2.2.2
Three-Phase Fault
Three-phase (3Ø) fault detection
(
Figure 2-3)
is accomplished by the logic operation of
one of the three ground units, plus the 3Ø fault output signal from the faulted phase
selector unit.
However, for a 3-phase fault condition, the computation of the distance units will be:
V
XG
- I
X
Z
CP
(3)
(and (V
Q
)
(4)
where V
XG
=
V
AG
, V
BG
, or V
CG
I
X
=
I
A
, I
B
or I
C
Z
CP
=
Zone reach setting (Pilot Ø, Z1Ø, Z2Ø,and Z3Ø) in secondary ohms
for
multi-phase faults.
V
Q
=
Quadrature phase voltages, i.e.,V
CB
, V
AC
and V
BA
for
↓
A,
φ
B and Ø
C units, respectively.
V
XG
I
X
k
O
I
O
+
[
]
Z
CG
–
k
o
Z
OL
Z
IL
–
Z
IL
------------------------
Z
R
GANG
PANG
–
(
)
∠
=
=
I
O
1
3
--- I
A
I
B
I
C
+
+
(
)
=
j V
XG
I
X
k
O
I
O
+
[
]
Z
CGR
+
(
)
Where
V
XG
V
AG
V
BG
or
V
C
,
,
=
I
X
I
A
I
B
or
I
C
, ,
=
Summary of Contents for REL 301
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Page 17: ...I L 40 386 3 1 10 10 94 2682F39 Sheet 1 of 2 Sub 2 Figure 1 2 REL 301 302 Layout Vertical...
Page 18: ...I L 40 386 3 10 94 1 11 2682F39 Sheet 2 of 2 Sub 2 Figure 1 3 REL 301 302 Layout Horizontal...
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Page 62: ...I L 40 386 3 10 94 2 41 Figure 2 32 CO 2 Curve Characteristics 619596 Sub 2...
Page 63: ...I L 40 386 3 2 42 10 94 Figure 2 33 CO 5 Curve Characteristic 619597 Sub 2...
Page 64: ...I L 40 386 3 10 94 2 43 Figure 2 34 CO 6 Curve Characteristic 619598 Sub 2...
Page 65: ...I L 40 386 3 2 44 10 94 Figure 2 35 CO 7 Curve Characteristic 619599 Sub 2...
Page 66: ...I L 40 386 3 10 94 2 45 Figure 2 36 CO 8 Curve Characteristic 619600 Sub 2...
Page 67: ...I L 40 386 3 2 46 10 94 Figure 2 37 CO 9 Curve Characteristic 619601 Sub 2...
Page 68: ...I L 40 386 3 10 94 2 47 Figure 2 38 CO 11 Curve Characteristic 619602 Sub 2...
