Differential protection
M13062-1 v22
Table 33. Restricted earth-fault protection, low impedance REFPDIF
Function Range or value Accuracy
Operating characteristic Adaptable ±1.0% of I
r
at I ≤ I
r
±1.0% of I at I > I
r
Reset ratio > 95% -
Minimum pickup, IdMin (4.0-100.0)% of IBase ±1.0% of I
r
Directional characteristic Fixed 180 degrees or ±60 to ±119
degrees
±2.0 degrees
Operate time, trip at 0 to 10 x IdMin Min. = 15 ms
Max. = 30 ms
-
Reset time, trip at 10 x IdMin to 0 Min. = 15 ms
Max. = 30 ms
-
Second harmonic blocking 40.0% of fundamental ±1.0% of I
r
M13081-1 v13
Table 34. High impedance differential protection, single phase HZPDIF
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
See
1)
-
Operate time at 0 to 10 x U
d
Min. = 5 ms
Max. = 15 ms
Reset time at 10 x U
d
to 0 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 x U
d
to 0 Min. = 50 ms
Max. = 70 ms
Critical impulse time 15 ms typically at 0 to 2 x U
d
-
1)
The value U
2
Trip/ R should always be lower than Stabilizing resistor thermal rating to allow continuous activation during testing. If this value is exceeded, testing should be
done with a transient faults. Typical value for the thermal rating of the resistor is 100W.
Line differential protection RED670
1MRK 505 379-BEN N
Hitachi Power Grids 75
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