ABB REL650 series, Applications Manual

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Protected Object
CT 800/1
Star Connected
IED
ANSI11000026-4-en.vsd
4
1
2
3
A
IA IB IC
B C
IA
IB
IC
SMAI_20_2
BLOCK
REVROT
^GRP2L1
^GRP2L2
^GRP2L3
^GRP2N AI3P
AI1
AI2
AI3
AI4
AIN
5
ANSI11000026 V4 EN
Figure 40: Wye connected three-phase CT set with its star point away from the protected object
In the example in figure 40 case everything is done in a similar way as in the above
described example ( figure 39 ). The only difference is the setting of the parameter
CTStarPoint of the used current inputs on the TRM (item 2 in the figure):
• CTprim =600A
• CTsec =5A
• CTWyePoint =FromObject
Inside the IED only the ratio of the first two parameters is used. The third parameter as set
in this example will negate the measured currents in order to ensure that the currents are
measured towards the protected object within the IED.
4.2.3.5 Example how to connect single-phase CT to the IED
Figure 41 gives an example how to connect the single-phase CT to the IED. It gives an
overview of the required actions by the user in order to make this measurement available
to the built-in protection and control functions within the IED as well.
For correct terminal designations, see the connection diagrams valid for
the delivered IED.
Section 4
1MRK 506 334-UUS A
Analog inputs
98
Application manual