Application and Setting Notes for Measuring Point Current 3-Phase
(I-3ph)
The supervision function settings are also located in the current measuring point. You can find the description
of these settings in chapter 8 Supervision Functions.
Parameter: CT connection
•
Default setting (_:8881:115) CT connection = 3-phase + IN-separate
The parameter CT connection shows the connection type of the current transformer for the 3-phase
current measuring point. The parameter can be found in the DIGSI 5 project tree under Name of the device
→ Parameter → Power system → Measuring point I 3-phase. You cannot change the connection type of
the current transformer in the Power system.
You can change the connection type of the current transformer only under measuring point routing in DIGSI 5.
Under Name of the device → Measuring point routing → Current measuring points, select the desired
connection type under Connection type. The following types of connections are possible:
•
3-phase + IN-separate
•
3-phase + IN
•
3-phase
•
3-phase, 2 primary CT
•
3ph,2prim.CT + IN-sep
•
2ph, 2p. CT + IN-sep
Depending on the connection type selected, you must route the measured values to the terminals of the
current measuring point in DIGSI 5. You can find connection examples for current transformers in chapter A.
4 Connection Examples for Current Transformers. The connection examples provide assistance when selecting
the type of connection.
Parameter: Tracking
•
Default setting (_:8881:127) Tracking = active
With the parameter Tracking, you specify whether you would like to work with the sampling-frequency
tracking function.
Parameter Value
Description
active
If the parameter Tracking = active has been set, the measuring point
will be included when determining the sampling frequency. If possible, only
the 3-phase measuring points shall be considered.
Siemens recommends using the default setting.
Note: If the parameter Tracking = active , the determined sampling
frequency applies to all functions in the device not using fixed sampling
rates.
inactive
If the channels of the measuring point are not to be considered for deter-
mining the sampling frequency, please select the setting value inactive.
Parameter: Rated primary current
•
Default setting (_:8881:101) Rated primary current = 1000 A
With the Rated primary current parameter, the active rated primary current of the current transformer
is set.
If you change configuration of the setting Rated primary current, for example, from 1000 A to 500 A
using the operation panel, restart the device to ensure that the change of the current transformer ratios was
accepted.
5.4
Power-System Data
5.4 Application and Setting Notes for Measuring Point Current 3-Phase (I-3ph)
SIPROTEC 5, Fault Recorder, Manual 113
C53000-G5040-C018-5, Edition 11.2017