Siemens 7SJ82 Manual page 545

Table 6-9
Connection Type of
the Measuring Point
I-3ph
3-phase
3-phase + IN
3-phase + IN-separate
Method of Measurement
The stage calculates the RMS value of 3I0 since this value takes into account the higher-order harmonics
components and the direct component (DC). Both components contribute to the thermal load.
Maximum 3I0 of the Fault
The stage records the maximum RMS value of 3I0 during the intermittent ground fault. The statistic value
max. is a percentage value calculated through dividing the primary maximum RMS value by the rated current
value of the protected object. With the coming operate signal, this value is logged via the information
max. .
Pickup and Intermittent Ground-Fault Indication
When 3I0 exceeds the threshold value, the pickup signals
The stage generates the
eter Pickup extension time).
The stage counts the
interm.GF, the
issued anymore after the issue of the
[DwIntFaD, 2, en_US]
Figure 6-112
17 These values apply for a secondary rated current of 1 A. The values need to be multiplied by 5 when the secondary rated current is 5 A.
18 If the connection type is without IN, such as 3-phase, the current threshold value is a calculated 3I0 value.
19 If the connection type is with IN, such as 3-phase + IN, the current threshold value is a measured IN value.
SIPROTEC 5, Overcurrent Protection, Manual
C53000-G5040-C017-8, Edition 07.2017
Threshold Setting Range with Different Connection Types
Current Threshold 3I0/IN
Calculated 3I0 18
Measured IN 19
Measured IN and calculated
3I0 when IN > 1.6 A
Stabilized pickup signal by extending the Pickup for a defined time (param-
Pickup signals. If the counted number reaches the configured No. pickups till
Intermittent gnd.flt. signal is issued. The signal Limited pickup (log) is not
Intermittent gnd.flt. signal.
Fault Detection of the Intermittent Ground-Fault Protection
Protection and Automation Functions
6.13 Non-Directional Intermittent Ground-Fault Protection
CT Terminal Type
4 x Protection
3 x Protection, 1 x sensitive 0.030 A to 35.000 A
4 x Measurement
4 x Protection
4 x Measurement
3 x Protection, 1 x sensitive 0.001 A to 35.000 A
Pickup and Limited pickup (log) are issued.
Threshold Setting
Range
(Secondary) 17
0.030 A to 35.000 A
0.001 A to 1.600 A
0.030 A to 35.000 A
0.001 A to 1.600 A
3I0
3I0
545