Siemens 6MD85, Manual

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Application and Setting Notes
Parameter:
Directional mode
•
Default setting
(_:8131:105) Directional mode
=
forward
You use the
Directional mode
parameter to define the directional mode of the stage.
Parameter Value Description
forward
Select this setting if the stage is to work in a forward direction (in the direc-
tion of the line).
reverse
Select this setting if the stage is to work in a reverse direction (in the direc-
tion of the busbar).
Parameter:
Method of measurement
•
Recommended setting value
(_:8131:8) Method of measurement
=
fundamental comp.
With the
Method of measurement
parameter, you define whether the stage uses the
fundamental
comp.
(standard method) or the calculated
RMS value
.
Parameter Value Description
fundamental comp.
Select this method of measurement if harmonics or transient current peaks
are to be suppressed.
Siemens recommends using this method as the standard method.
RMS value
Select this method of measurement if you want the stage to take harmonics
into account (for example, at capacitor banks). Consider that aperiodic DC
components present in the secondary circuit are measured and can cause
an overfunction.
For this method of measurement, do not set the
threshold value
of the
stage to less than 0.1 I
rated,sec
. If currents from more than one measuring
point are added up in the current interface of a function group, the setting
value should not be set lower than 0.1 I
rated,sec
multiplied by the number of
added currents.
Parameter:
Directional comparison
,
Release via input signal
•
Default setting
(_:8131:104) Directional comparison
=
no
•
Default setting
(_:8131:106) Release via input signal
=
no
These 2 parameters are not visible in the basic stage.
You use these parameters to define whether the stage is to be used for directional comparison protection.
Directional comparison protection is performed via the
Direction
and
>Release delay & op.
signals.
Parameter Value Description
no
The stage is not used for directional comparison protection.
yes
If the
Directional comparison
parameter is set to
yes
, the
Release
via input signal
parameter, the
Direction
output signal, and the
>Release delay & op.
input signal become available.
If the
Release via input signal
parameter is set to
yes
, the start of
the time delay, and therefore also the operate signal of the stage, are only
enabled if the
>Release delay & op.
input signal is active. The
>Release delay & op.
input signal must be connected to the release
information from the opposite end (forward information from the
Direc-
tion
output signal); see also the application example in chapter
7.6.10 Application Notes for Directional Comparison Protection .
7.6.4.2
Protection and Automation Functions
7.6 Directional Overcurrent Protection, Phases
672 SIPROTEC 5, High-Voltage Bay Controller, Manual
C53000-G5040-C015-9, Edition 11.2017