current value is fed to the Instantaneous residual overcurrent protection (EFPIOC).
In a comparator the RMS value is compared to the set operation current value of
the function (IN>>).
If the residual current is larger than the set operation current a signal from the
comparator is set to true. This signal will, without delay, activate the output signal
TRIP.
There is also a possibility to activate a preset change of the set operation current
via a binary input (enable multiplier ENMULT). In some applications the operation
value needs to be changed, for example, due to transformer inrush currents.
The operation current value IN>>, is limited to be between IN>>Max and
IN>>Min. The default values of the limits are the same as the setting limits for
IN>>, and the limits can only be used for reducing the allowed range of IN>>.
This feature is used when remote setting of the operation current value is allowed,
making it possible to ensure that the operation value used is reasonable. If IN>> is
set outside IN>>Max and IN>>Min, the closest of the limits to IN>> is used by
the function. If IN>>Max is smaller then IN>>Min, the limits are swapped. The
principle of the limitation is shown in Figure
82.
hi
u
lo
y
MIN
MAX
IN>>_used
IN>>Max
IN>>
IN>>Min
IEC17000015-1-en.vsdx
IEC17000015 V1 EN-US
Figure 82: Logic for limitation of used operation current value
EFPIOC function can be blocked from the binary input BLOCK. The trip signals
from the function can be blocked from the binary input BLKAR, that can be
activated during single pole trip and autoreclosing sequences.
8.3.8 Technical data
IP11450-1 v1
M12340-2 v9
Table 82: EFPIOC technical data
Function
Range or value Accuracy
Operate current (5-2500)% of lBase ±1.0% of I
r
at I ≤ I
r
±1.0% of I at I > I
r
Reset ratio > 95% at (50–2500)% of lBase -
Operate time at 0 to 2 x I
set
Min. = 15 ms
Max. = 25 ms
-
Reset time at 2 x I
set
to 0 Min. = 15 ms
Max. = 25 ms
-
Table continues on next page
1MRK 505 394-UEN A Section 8
Current protection
Line differential protection RED650 2.2 IEC 181
Technical manual
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