ABB RET670 Applications Manual page 47

1MRK504116-UUS C
A B
CT 600/5
Star Connected
Protected Object
ANSI13000002 V2 EN
Figure 8: Wye connected three-phase CT set with wye point towards the protected object
Application manual
C
1
I_A
I_B
I_C
Where:
1) The drawing shows how to connect three individual phase currents from a wye connected three-
phase CT set to the three CT inputs of the IED.
2) The current inputs are located in the TRM. It shall be noted that for all these current inputs the
following setting values shall be entered for the example shown in Figure8.
'
• CTprim=600A
• CTsec=5A
• CTStarPoint=ToObject
Inside the IED only the ratio of the first two parameters is used. The third parameter
(CTStarPoint=ToObject) as set in this example causes no change on the measured currents. In
other words, currents are already measured towards the protected object.
Table continues on next page
IED
2
3
Section 3
IED application
4
SMAI_20
ANSI3000002-2-en.vsd
41