The voltage waveform is then filtered in order to get its RMS value. Note that used
filtering is designed in such a way that it ensures complete removal of the DC current
component which may be present in the primary fault current. The voltage RMS value
is then compared with set Alarm and Trip thresholds. Note that the TRIP signal is
intentionally delayed on drop off for 30 ms within the function. The measured RMS
voltage is available as a service value from the function. The function has block and
trip block inputs available as well.
IEC05000301 V1 EN
Figure 46: Logic diagram for 1Ph High impedance differential protection
HZPDIF
6.2.8 Technical data
Table 53: HZPDIF technical data
Function
Range or value Accuracy
Operate voltage (10-900) V
I=U/R
± 1.0% of I
r
at I ≤ I
r
± 1.0% of I at I > I
r
Reset ratio >95% at (30-900) V -
Maximum
continuous power
U>Trip
2
/SeriesResistor ≤200 W
-
Operate time at 0
to 10 x U
d
Min = 5 ms
Max = 15 ms
Reset time at 10
to 0 x U
d
Min = 75 ms
Max = 95 ms
Critical impulse
time
2 ms typically at 0 to 10 x U
d
-
Operate time at 0
to 2 x U
d
Min = 25 ms
Max = 35 ms
Reset time at 2 to
0 x U
d
Min = 50 ms
Max = 70 ms
Critical impulse
time
15 ms typically at 0 to 2 x U
d
-
1MRK502052-UEN B Section 6
Differential protection
145
Technical manual
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