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Functions
2.11 Ground Fault Protection 64, 67N(s), 50N(s), 51N(s)
of Figure 2-62 "Directional curve for cos-ϕ-measurement" in the functional description of the sensitive ground
fault detection).
Electrical Machines
One may set the value COS ϕ for the measurement method and use a correction angle of +45° for electrical
motors supplied from a busbar in an ungrounded system, since the ground current is often composed of an
overlap of the capacitive ground current from the system and the resistive current of the load resistance (left
part of Figure "Directional characteristic for cos-ϕ-measurement" in the functional description of the sensitive
ground fault detection).
Information on the Configuration of the Current Threshold
With devices with sensitive ground fault input, generally settings may be entered in primary values with consid-
eration given to the ratio of the applicable current transformer. However, problems related to the resolution of
the pickup currents can occur when very small settings and small nominal primary currents are involved. The
user is therefore encouraged to enter settings for the sensitive ground fault detection in secondary values.
2.11.5
Settings
Addresses which have an appended "A" can only be changed with DIGSI, under "Display Additional Settings".
The table indicates region-specific default settings. Column C (configuration) indicates the corresponding sec-
ondary nominal current of the current transformer.
Addr.
Parameter
3101
Sens. Gnd Fault
3102
CT Err. I1
3102
CT Err. I1
3103
CT Err. F1
3104
CT Err. I2
3104
CT Err. I2
3105
CT Err. F2
3106
VPH MIN
3107
VPH MAX
3109
64-1 VGND
3110
64-1 VGND
204
C
Setting Options
OFF
ON
ON with GF log
Alarm Only
1A
0.001 .. 1.600 A
5A
0.005 .. 8.000 A
1A
0.05 .. 35.00 A
5A
0.25 .. 175.00 A
0.0 .. 5.0 °
1A
0.001 .. 1.600 A
5A
0.005 .. 8.000 A
1A
0.05 .. 35.00 A
5A
0.25 .. 175.00 A
0.0 .. 5.0 °
10 .. 100 V
10 .. 100 V
1.8 .. 200.0 V; ∞
10.0 .. 225.0 V; ∞
Default Setting
OFF
(Sensitive) Ground Fault
0.050 A
Current I1 for CT Angle
Error
0.250 A
1.00 A
Current I1 for CT Angle
Error
5.00 A
0.0 °
CT Angle Error at I1
1.000 A
Current I2 for CT Angle
Error
5.000 A
10.00 A
Current I2 for CT Angle
Error
50.00 A
0.0 °
CT Angle Error at I2
40 V
L-Gnd Voltage of Faulted
Phase Vph Min
75 V
L-Gnd Voltage of Unfault-
ed Phase Vph Max
40.0 V
64-1 Ground Displace-
ment Voltage
70.0 V
64-1 Ground Displace-
ment Voltage
SIPROTEC, 7SK80, Manual
E50417-G1140-C344-A5, Release date 11.2012
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