ABB Relion 670 Series Applications Manual page 78

Section 4
Analog inputs
ANSI06000196 V1 EN-US
Figure 23: Example how to set CT_WyePoint parameters in the IED
For busbar protection it is possible to set the
The first solution will be to use busbar as a reference object. In that case for all CT inputs marked
with 1 in figure 23, set
CT_WyePoint = FromObject .
set
The second solution will be to use all connected bays as reference objects. In that case for all CT
inputs marked with 1 in figure 23, set
with 2 in figure 23, set
Regardless which one of the above two options is selected busbar differential protection will
behave correctly.
The main CT ratios must also be set. This is done by setting the two parameters
for each current channel. For a 1000/5 A CT the following setting shall be used:
72
CT_WyePoint parameters in two ways.
CT_WyePoint = ToObject , and for all CT inputs marked with 2 in figure 23,
CT_WyePoint = FromObject , and for all CT inputs marked
CT_WyePoint = ToObject .
Busbar
Busbar
Protection
1
2
1MRK 511 358-UUS A
2
1
en06000196_ansi.vsd
CTsec and CTprim
Application manual