Siemens 7SJ82, Manual

Page: 423 / 1638

Parameter Value Description
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
(_:8161:110) Directional comparison
=
no
•
Default setting
(_:8161:112) 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
6.6.10 Application Notes for Directional Comparison Protection .
Parameter: Non-directional pickup
•
Recommended setting value
(_:8161:113) Non-directional pickup
=
at volt.< &
mem.empty
This parameter is not visible in the basic stage.
Parameter Value Description
at volt.< & mem.empty
Select this setting if the stage is to pick up in a non-directional manner if the
voltage memory is empty and determining of direction has to be performed
at low voltages (3-phase close-up fault). An empty voltage memory may
exist, for example, if there is a voltage transformer at the line end and the
CB trips.
Siemens recommends using the default setting.
no
Select this setting if determining of direction is required under all circum-
stances, that is, even in the event of pickup on a 3-phase close-up fault.
Parameter:
Type of character. curve
•
Default setting
(_:8161:130) Type of character. curve
=
IEC normal inverse
The device offers all the usual inverse-time characteristic curves according to IEC and ANSI. Select the
Type
of character. curve
required for your specific application.
Protection and Automation Functions
6.6 Directional Overcurrent Protection, Phases
SIPROTEC 5, Overcurrent Protection, Manual 423
C53000-G5040-C017-8, Edition 07.2017