ABB Relion 670 Series Applications Manual page 87

1MRK 511 358-UUS A
Protected Object
A B
INS
a)
b)
INS
ANSI11000029 V3 EN-US
Figure 30: Connections for single-phase CT input
Where:
1)
2)
3)
4)
Application manual
C
1
(+)
(-)
(+)
(-)
shows how to connect single-phase CT input in the IED.
is TRM where these current inputs are located. It shall be noted that for all these current inputs the
following setting values shall be entered.
For connection (a) shown in figure 30:
CT prim = 1000 A
CT sec = 1A
CTWyePoint = ToObject
For connection (b) shown in figure 30:
CT prim = 1000 A
CT sec = 1A
CTWyePoint = FromObject
shows the connection made in SMT tool, which connect this CT input to the fourth input channel of
the preprocessing function block 4).
is a Preprocessing block that has the task to digitally filter the connected analog inputs and calculate
values. The calculated values are then available for all built-in protection and control functions within
the IED, which are connected to this preprocessing function block.
If frequency tracking and compensation is required (this feature is typically required only for IEDs
installed in the power plants) then the setting parameters
IED
2
(+)
(-)
4
SMAI_20_2
BLOCK
REVROT
^GRP2_A
^GRP2_B
^GRP2_C
^GRP2_N
3
ANSI11000029-3-en.vsd
DFTReference shall be set accordingly.
Section 4
Analog inputs
AI3P
AI1
AI2
AI3
AI4
AIN
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