ABB RELION RET670, Applications Manual

Page: 91 / 1016

For correct terminal designations, see the connection diagrams valid for
the delivered IED.
Protected Object
A B C
IED
IN
P
2
4
ANSI11000029-3-en.vsd
3
C
T
1
0
0
0
/1
a)
b)
INS
INS
(+)
(+)
(-)
(-)
(+)
(-)
1
SMAI_20_2
BLOCK
REVROT
^GRP2_A
^GRP2_B
^GRP2_C
^GRP2_N AI3P
AI1
AI2
AI3
AI4
AIN
ANSI11000029 V3 EN-US
Figure 19: Connections for single-phase CT input
Where:
1) shows how to connect single-phase CT input in the IED.
2) 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 Fgure 19 :
CTprim= 1000 A
CTsec= 1A
CTWyePoint=ToObject
For connection (b) shown in Figure 19 :
CTprim= 1000 A
CTsec= 1A
CTWyePoint=FromObject
3) shows the connection made in SMT tool, which connect this CT input to the fourth input
channel of the preprocessing function block 4).
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
DFTReference shall be set
accordingly.
1MRK 504 163-UUS A
Section 4
Analog inputs
Transformer protection RET670 2.2 ANSI 85
Application manual