Distance Relay Setting Examples
GARD 8000 Distance Relay
RFL Electronics Inc.
Description Range
Units
Step
Actual
Gnd. Distance Char.
Selection of mho, reactance (quadrilateral), mho AND reactance,
mho OR reactance for the ground distance elements. Note that the
setting ‘Mho AND reactance’ requires both characteristics to
operate for a trip to be produced. ‘Mho OR reactance’ produces a
trip from either element. For applications when a larger resistive
reach as compared to the reactive reach is required, the setting
‘Reactance’ or ‘Reactance OR Mho’ should be used.
Reactance,
Mho,
Reactance
and MHO,
Reactance
OR MHO
-
1
Mho
Phase Distance Char.
Selection of mho, reactance (quadrilateral), reactance AND mho,
reactance OR mho the phase distance elements.
Reactance,
Mho,
Reactance
and MHO,
Reactance or
MHO - 1
Mho
Characteristic Angle
Characteristic line angle in degrees for the directional element for
the quadrilateral characteristic. It is typically set at 75 degrees. See
Description of Operation for definition of this angle.
0 - 90
deg
1
75
Lagging phase for PH-PH-G faults
For two-phase-to-ground faults, the leading phase-ground element
may overreach and is not allowed to measure. The lagging phase
can be allowed to operate as it will underreach and is enabled by
this setting. Two phase to ground faults will generally by detected
by phase-phase elements, but in case high resistance is expected
for these type of faults, the setting should be YES.
No - Yes
-
1
No
Distance Block Timer
When a digital input is used for blocking the distance protection,
this timer provides drop-out delay of the block signal. Not used in
factory default logic.
0 - 1000
ms
50
150
Duration memory
This setting determines the polarization voltage memory
duration, in cycles. Recommended setting is 2 cycles.
2 - 80
Cycles 1
2
Voltage Threshold
Voltage threshold for the memory polarization. When the
measured voltage is below the set threshold, memory is used.
0.1 – 5
V
0.1
1
August 1, 2009
8-11
973.334.3100
