Example 2 - ABB REL650 Applications Manual

Section 4
Analog inputs
4.2.3.2
92
Transformer
I
p
I
s
Transformer
protection
IED
Setting of current input:
Set parameter
CT_WyePoint with
Transformer as
reference object.
Correct setting is
"ToObject"
ANSI11000020 V2 EN
Figure 36: Example how to set CT_WyePoint parameters in the IED
The figure 36 shows the most common case where the objects have their own CTs. For the
transformer protection, the protected object is the transformer. Therefore both
CT_WyePoint directions should be set ToObject. For the line protection, the protected
object is the line. The line CT is grounded towards the busbar, therefore the CT_WyePoint
should be set FromObject.

Example 2

Two IEDs used for protection of two objects and sharing a CT.
I
I
p
p
I
s
Setting of current input:
Set parameter
CT_WyePoint with
Transformer as
reference object.
Correct setting is
"ToObject"
1MRK 506 334-UUS A
Line
Line
Reverse Forward
Definition of direction for
directional functions
Line protection
IED
Setting of current input:
Set parameter
CT_WyePoint with
Line as
reference object.
Correct setting is
"ToObject"
ANSI11000020-2-en.vsd
Application manual