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2 Functions
Figure 2-36
Logic diagram of the high current switch on to fault protection
2.8.2
Setting Notes
General
A prerequisite for the application of the direct and remote tripping functions is that
during the configuration of the scope of functions (Section 2.1.1) in address
124HS/SOTF-O/C = Enabled was applied. At address 2401 FCT HS/SOTF-O/C it
can also be switched ON or OFF.
I>>> Stage
The magnitude of fault current which leads to the pickup of the I>>> stage is set as
I>>> in address 2404. This stage is active only during the connecting of the local end
while the circuit breaker at the other end of the protected object is open. Choose a
value which is high enough for the protection not to pick up on the RMS value of the
inrush current produced during the connection of the protected object. On the other
hand, fault currents flowing through the protected object need not be considered.
When using a PC and DIGSI for the parameterisation, the values can be optionally
entered as primary or secondary quantities. If secondary quantities are used, all cur-
rents must be converted to the secondary side of the current transformers.
The I>>>>stage (address 2405) works regardless of the circuit breaker position.
I>>>>stage
Since it trips extremely fast it must be set high enough not to pickup on a load current
flowing through the protected object. This means that it can be used only if the protect-
ed object allows current grading, as is the case with transformers, series reactors or
94
7SD610 Manual
C53000-G1176-C145-4
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