Setting Notes - Siemens Siprotec 7UM611 Manual

2 Functions
Figure 2-7 Logic Diagram of I>> Stage with Direction Element
2.7.2

Setting Notes

General The high current stage I>> of the time overcurrent protection will only be effective and
available if address 113 O/C PROT. I>> is set to either directional or Non-
Directional on configuration. If the function is not needed it is set to Disabled.
If direction acquisition is used, make sure that the CT and VT sets are consistent.
Address 1301 O/C I>> is used to switch the definite time I>> stage for phase currents
High-current Stage
ON and OFF, or to block only the trip command (Block relay). The high-current
I>>
stage I>> (Parameter 1302 and its associated delay time T I>>, 1303) is used for
current grading with large impedances existing for example with transformers, motors
or generators. It is set in a way ensuring that it picks up for faults up to this impedance.
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7UM61 Manual
C53000-G1176-C127-3