ABB REL650 Applications Manual page 102

Section 4
Analog inputs
A B
CT 600/5
Star Connected
Protected Object
ANSI13000002 V2 EN
Figure 39: Wye connected three-phase CT set with wye point towards the protected object
96
For correct terminal designations, see the connection diagrams valid for
the delivered IED.
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
• 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
1MRK 506 334-UUS A
4
SMAI_20
ANSI3000002-2-en.vsd
figure 39.
Application manual