ABB REB670 Applications Manual page 70

Section 4
Analog inputs
4.2.2.3
Setting of current input:
Set parameter
CT_WyePoint with
Transformer as
reference object.
Correct setting is
"ToObject"
ANSI05000461 V1 EN
Figure 17: Example how to set CT_WyePoint parameters in the IED
64
Example 3
One IED used to protect two objects.
Transformer
Transformer and
Line protection
In this example one IED includes both transformer and line protection and the line
protection uses the same CT as the transformer protection does. For both current input
channels the CT direction is set with the transformer as reference object. This means that
the direction Forward for the line protection is towards the transformer. To look towards
the line the direction of the directional functions of the line protection must be set to
Reverse. The direction Forward/Reverse is related to the reference object that is the
transformer in this case.
When a function is set to Reverse and shall protect an object in reverse direction it shall be
noted that some directional functions are not symmetrical regarding the reach in forward
and reverse direction. It is in first hand the reach of the directional criteria that can differ.
Setting of current input:
Set parameter
CT_WyePoint with
Transformer as
reference object.
Correct setting is
"ToObject"
1MRK 505 337-UUS -
Line
Forward Reverse
Definition of direction for
directional
line functions
en05000461_ansi.vsd
Application manual