ABB Relion 650 Series Applications Manual page 45

1MRK 505 287-UUS B
With correct setting of the primary CT direction,
positive quantity always flows towards the protected object and a direction defined as Forward is
always looking towards the protected object. The following examples show the principle.
4.2.3.1 Example 1
Two IEDs used for protection of two objects.
I
I
s
Setting of current input:
Set parameter
CT_WyePoint with
Transformer as
reference object.
Correct setting is
"ToObject"
ANSI11000020 V2 EN-US
Figure 9:
The figure
transformer protection, the protected object is the transformer. Therefore both
directions should be set
CT is grounded towards the busbar, therefore the
4.2.3.2 Example 2
Two IEDs used for protection of two objects and sharing a CT.
Busbar protection REB650
Application manual
Transformer
p
Transformer
protection
IED
Setting of current input:
Set parameter
CT_WyePoint with
Transformer as
reference object.
Correct setting is
"ToObject"
Example how to set CT_WyePoint parameters in the IED
9 shows the most common case where the objects have their own CTs. For the
ToObject . For the line protection, the protected object is the line. The line
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CT_WyePoint set to FromObject or ToObject , a
Line
I
I
p
p
I
s
Setting of current input:
Set parameter
CT_WyePoint with
Line as
reference object.
Correct setting is
"ToObject"
CT_WyePoint should be set FromObject .
Line
Reverse Forward
Definition of direction for
directional functions
Line protection
IED
ANSI11000020-2-en.vsd
CT_WyePoint
Section 4
Analog inputs
SEMOD55055-23 v5
SEMOD55055-29 v5
39