Low-Voltage Measurement; Determination Of Medium Voltage Via Low-Voltage Measurements - Siemens SICAM Manual

Low-Voltage Measurement

4.1.30
The device can be configured for low-voltage measurement. In the low-voltage system, 230 V is directly
connected to the V
voltage system with appropriate current-transformer sensors.
This function can be selected by configuring the Secondary voltage parameter to 230 V.
In this mode, the settings for primary voltage do not have any relevance.
The following figure shows how the device is connected to the low-voltage system.
[dw_sfcm-lowvolmsrmt, 2, en_US]
Figure 4-20

Determination of Medium Voltage via Low-Voltage Measurements

4.1.31
The voltages in the medium-voltage (MV) system can be determined by measuring the voltages from the low-
voltage (LV) system. In this variant, the voltage inputs (V
secondary side of the transformer in the LV system and the current inputs (I
connected to the LoPo current sensors in the medium-voltage system.
The figure illustrates the transformer type (Dy-11) used in the medium-voltage/low-voltage measurement. For
more information about transformer types, refer to
[dw_sfcm_mv_lv_measurement, 2, en_US]
Figure 4-21
This function can be selected by configuring the Secondary voltage parameter to 400/√3. By using this
application, no additional VTs are necessary. The fault determinations are made with the help of LV-side
voltage references.
The device is able to detect the direction of phase faults and ground faults in solidly grounded MV networks.
The primary voltages affected by transformer losses can be corrected by providing an offset in the Primary
voltage correction parameter.
SICAM, Feeder Condition Monitor, Manual
E50417-H8940-C580-A4, Edition 03.2019
, V , and V terminals. The current terminals I
1 2 3
Low-Voltage Measurement
Medium-Voltage/Low-Voltage Measurement
, I , and I are also connected in the low-
1 2 3
, V , and V ) of the device are connected to the
1 2 3
, I
1 2
Transformer Type, Page 114.
Device Functions
4.1 Description
, and I ) of the device are
3
53