Enumeration name Value
BC Fault 5
CA Fault 6
ABC Fault 7
Table 911: Enumeration values for integer monitored data signal RELEASE_PP
Enumeration name Value
No fault -5
AB Fault 4
BC Fault 5
CA Fault 6
ABC Fault 7
The phase selection function can be set to issue an operate signal as the
faulted phase selection uses independent measuring elements from the distance
protection zones. This can be applied as a back-up protection for the measurement
zones. The time delay of the operate signals is defined with the
Operate delay GFC
setting. The operate signal is the binary output OPERATE_GFC.
Faulted loop phase selection by the overcurrent method
The "Overcurrent" method is the basic method used for identifying the faulted
phases. It can be used in applications where the fault current magnitude exceeds
the load current despite the possible changes in the network configuration and fault
type.
In the overcurrent-based faulted phase selection method, the amplitude of each
phase current is compared to the
Str A Ph Sel GFC
threshold setting. If the phase
current magnitude exceeds the value of
Str A Ph Sel GFC
, that particular phase is
faulty.
Earth-fault recognition is always required to release a phase-to-earth
impedance-measuring element.
Table 912: Conversion from element start to monitored data signals
Start of element START_GFC STARTS_GF
C
RELEASE_P
E
RELEASE_P
P
I
A
> &
EARTH_FLT
TRUE AG Fault AG Fault No fault
I
B
> &
EARTH_FLT
TRUE BG Fault BG Fault No fault
I
C
> &
EARTH_FLT
TRUE CG Fault CG Fault No fault
I
A
> & I
B
>
TRUE AB Fault No fault AB Fault
Table continues on the next page
Protection functions 1MRS759142 F
950 REX640
Technical Manual
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