2.Auto-Reclosure Function; Connections; 1.Protection Signal Routing; 2.Indication And Control Connections - ABB REX 521 Technical Reference Manual, Standard Configurations

1MRS 751802-MUM
11.4.4.2.
11.4.5.
11.4.5.1.
11.4.5.2.
11.4.6.
Protection Relay
Technical Reference Manual, Standard Configurations
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Detection of a cross-country fault can be implemented by non-directional earth-fault
protection. In a case where the fault current is lower than the start current level of
the overcurrent protection because of the fault resistance, the separated non-
directional high-set earth-fault stage I
this arrangement it is also possible to get clear indication of the fault type if the
settings are selected so that this protection stage will operate only in double earth-
fault situations.
In H04 standard configuration the measurement channel I
measurement is fixedly connected to the non-directional earth-fault stages.
Auto-reclosure function
The auto-reclosure function can be implemented as described in the seventh
application example (chapter 10.3.)

Connections

All the necessary settings for the connections and signal routings can be set via the
Relay Setting Tool or the local HMI.
Protection signal routing
The settings for the protection signal routing can be implemented as described in the
first application example (chapter 9.1.).
Indication and control connections
The connections for indication and control can be implemented as described in the
first application example (chapter 9.1.), except the signals for the open and close
buttons that in this example are disconnected to free the digital inputs for other
functionality. Local control can be executed via the HMI according to the
instructions in Operator's Manual (1MRS 751107-MUM).

Implementations

The implementations for the seventh application example (chapter 10.3.) are also
applicable for this application example.
EF in phase L2
EF in phase L3
>> can be used for detecting the fault. With
0
for earth-fault current
0
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