ABB REB670 Series Applications Manual page 347

1MRK 505 370-UEN D
13.6.2 Application
The Fixed signals function (FXDSIGN) has nine pre-set (fixed) signals that can be used in the
configuration of an IED, either for forcing the unused inputs in other function blocks to a
certain level/value, or for creating certain logic. Boolean, integer, floating point, string types of
signals are available.
One FXDSIGN function block is included in all IEDs.
Example for use of GRP_OFF signal in FXDSIGN
The Restricted earth fault function (REFPDIF) can be used both for auto-transformers and
normal transformers.
When used for auto-transformers, information from both windings parts, together with the
neutral point current, needs to be available to the function. This means that three inputs are
needed.
IEC09000619 V3 EN-US
Figure 192: REFPDIF function inputs for autotransformer application
For normal transformers only one winding and the neutral point is available. This means that
only two inputs are used. Since all group connections are mandatory to be connected, the third
input needs to be connected to something, which is the GRP_OFF signal in FXDSIGN function
block.
FXDSIGN
GRP_OFF
IEC09000620 V3 EN-US
Figure 193: REFPDIF function inputs for normal transformer application
Busbar protection REB670
Application manual
REFPDIF
I3PW1CT1
I3PW2CT1
I3P
IEC09000619_3_en.vsd
REFPDIF
I3PW1CT1
I3PW2CT1
I3P
IEC09000620_3_en.vsd
Section 13
Logic
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