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Table 2-10
MofPU = 1 to 1.94
1.00
1.06
1.13
1.19
1.25
1.31
1.38
1.44
Figure 2-73
Determination of Ground-faulted Phase
The phase connected to ground may be identified in an ungrounded or resonant grounded system, if the device
is supplied by three voltage transformers connected in a grounded-wye configuration or the phase-Ground volt-
ages are calculated. The phase in which the voltage lies below setting VPH MIN (address 3106) is identified
as the faulty phase as long as the other two phase voltages simultaneously exceed setting VPH MAX (address
3107). The setting VPH MIN must be set to less than the minimum expected operational phase-to-Ground volt-
age. A typical setting for this address would be 40 V. Setting VPH MAX must be greater than the maximum ex-
pected operational phase-to-Ground voltage, but less than the minimum expected operational phase-to-phase
voltage. For V
grounded system.
Displacement Voltage Element V
The displacement voltage 64-1 VGND (address 3109) or 64-1 VGND (address 3110) is the pickup of the
ground fault detection and a release condition for the direction determination (when setting the direction char-
acteristic to cos ϕ / sin ϕ). If the direction characteristic is set to V0/I0 ϕ mea., the displacement voltage
element is entirely independent of the current elements. Depending on the configuration at address 213 VT
Connect. 3ph, only the applicable limit value address 3109 64-1 VGND or 3110 64-1 VGND is accessible.
That is, if two phase-to-phase voltages and the displacement voltage V
sured displacement voltage is used directly for ground fault recognition. The threshold for V
3109 64-1 VGND, where a more sensitive setting can be made than with a calculated displacement voltage.
Please note that with displaced voltage V
SIPROTEC, 7SK80, Manual
E50417-G1140-C344-A5, Release date 11.2012
Preferential Values of Standardized Currents for User-specific Tripping Curves
MofPU = 2 to 4.75
1.50
2.00
1.56
2.25
1.63
2.50
1.69
2.75
1.75
3.00
1.81
3.25
1.88
1.94
Use of a user-defined Curve
= 100 V, approximately 75 V is a typical setting. These settings have no significance in a
Nom
0
2.11 Ground Fault Protection 64, 67N(s), 50N(s), 51N(s)
MofPU = 5 to 7.75
3.50
5.00
3.75
5.25
4.00
5.50
4.25
5.75
4.50
6.00
4.75
6.25
-voltage, the factor (in normal case = 1.73; see also Section 2.1.3.2)
0
MofPU p = 8 to 20
6.50
8.00
6.75
9.00
7.00
10.00
7.25
11.00
7.50
12.00
7.75
13.00
14.00
are supplied to the device, the mea-
0
is set at address
0
Functions
15.00
16.00
17.00
18.00
19.00
20.00
199
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