ABB Relion REQ650, Applications Manual

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3
3
1
REQ650 (A01)
Z
SC
: Low
Three-phase short circuit
Line protection zone 1 reach
IEC10000148-1-en.vsd
IEC10000148 V1 EN
Figure 14: Fault for step 1 setting
Recommended current setting is therefore 2000 A.
1. Set DirMode1 to Forward .
2. Set Characterist1 to IEC Def. Time .
For the time delay characteristic, definite time is used in this network.
3. Set I1> to 200% of IBase (2000 A primary current).
4. Set t1 to 0.4 s .
3.1.5.3 Calculating settings for step 2
The protection shall be able to detect all short circuits in the own busbar. A two-phase
short circuit in the busbar and high source impedance from the remote line end, as
shown in figure
15 , results in the following fault current for the protection:
145
3 3
3
2.6 85
2 2 10 2.5 17.5
ph
sc
sc line
U
I kA
Z Z j j
= × = × = Ð °
+ + +
EQUATION2343 V1 EN
1MRK 505 291-UEN A
Section 3
REQ650 setting examples
49
Application manual