Meshed Network Without Parallel Line - ABB REC670 Applications Manual

1MRK 511 401-UUS A
8.1.3.1
Bay control REC670 2.2 ANSI
Application manual
MultPU: The set operate current can be changed by activation of the binary input
MULTPU to the set factor MultPU.

Meshed network without parallel line

The following fault calculations have to be done for three-phase, single-phase-to-
ground and two-phase-to-ground faults. With reference to Figure 55, apply a fault in B
and then calculate the current through-fault phase current I
done using the minimum source impedance values for Z
impedance values for Z
B
B.
A
Z
~
A
IED
ANSI09000022 V1 EN-US
Figure 55: Through fault current from A to B: I
Then a fault in A has to be applied and the through fault current I
calculated, Figure 56. In order to get the maximum through fault current, the minimum
value for Z and the maximum value for Z
B
in order to get the maximum through fault current from A to
I
fB
Z
L
Fault
have to be considered.
A
Section 8
Current protection
. The calculation should be
fB
and the maximum source
A
B
Z
~
B
ANSI09000022-1-en.vsd
fB
has to be
fA
M12915-9 v8
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