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Parameter: Blk. by meas.-volt. failure
•
Recommended setting value (_:12391:10) Blk. by meas.-volt. failure = yes
You use the Blk. by meas.-volt. failure parameter to control the behavior of the stage when a
measuring-voltage failure is detected.
A measuring-voltage failure can only be detected if one of the following 2 conditions is met:
•
The device-internal supervision function Measuring-voltage failure detection is configured and
enabled.
•
The binary input signal
linked with the voltage-transformer circuit breaker.
Parameter Value
yes
no
Parameter: Detection of faulty phase
•
Default setting (_:12391:109) Detection of faulty phase = no
The Detection of faulty phase parameter controls how the stage responds to determine which phase
is affected by the ground fault.
Parameter Value
no
yes
Parameter: V< faulty ph-to-gnd volt.
•
Default setting (_:12391:104) V< faulty ph-to-gnd volt. = 30 V
Set the threshold value for determining which phase is affected by the ground fault in the V< faulty ph-
to-gnd volt. parameter. The setting value is a phase-to-ground quantity.
The set value must be smaller than the minimum phase-to-ground voltage occurring during operation.
Siemens recommends using the default setting V< faulty ph-to-gnd volt. = 30 V.
Parameter: V> healthy ph-to-gnd volt.
•
Default setting (_:12391:101) V> healthy ph-to-gnd volt. = 70 V
Set the threshold value for the 2 healthy phases in the V> healthy ph-to-gnd volt. parameter. The
setting value is a phase-to-ground measurand.
The set value must be above the maximum phase-to-ground voltage occurring during operation, but below
the minimum phase-to-phase voltage present during operation. At V
V, for example. Siemens recommends using the default setting V> healthy ph-to-gnd volt. = 70 V.
Operation as Supervision Function
If you want the stage to have a reporting effect only, the generation of the operate indication and fault
logging can be disabled via the Operate & flt.rec. blocked parameter.
SIPROTEC 5, Overcurrent Protection, Manual
C53000-G5040-C017-8, Edition 07.2017
>Open of the function block Voltage-transformer circuit breaker is
Description
The protection stage is blocked (= default setting). Siemens recommends
using the default setting.
The protection stage is not blocked.
Description
The phase affected by the ground fault is not determined.
Select the default setting if you do not want to use the stage to detect
ground faults, for example for applications in grounded systems.
After a pickup by the residual voltage, the device tries to determine which
phase is affected by the ground fault.
Select this setting for applications in isolated or arc-suppression-coil-
grounded systems.
Protection and Automation Functions
6.15 Sensitive Ground-Fault Detection
= 100 V, the value has to be set to 70
rated
611
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