i
i
NOTE
For higher accuracy, Siemens recommends measuring the ground current in compensated/isolated
systems.
Network Voltage Ratio
In the medium-voltage applications, higher rated voltage sensors can be used in the system with lower rated
voltages. For example, a 20-kV sensor can be used in a 10-kV primary voltage system. In this case, enter the
appropriate sensor voltage ratio and primary voltage settings to display the correct network voltage as
described in the following example:
If the primary rated voltage is equal to the rated sensor voltage, set both the parameters, that is
primary
voltage
and the
sensor voltage
as the primary rated voltage. For example, if a 20-kV sensor is used in
the 20-kV system, set the primary voltage and the sensor voltage equal to 20 kV.
Also when the primary rated voltage is lower than the rated sensor voltage, set the Primary voltage param-
eter equal to the primary rated voltage and the Sensor voltage parameter equal to the rated sensor voltage.
For example, if a 20-kV sensor is used in the 10-kV system, set the primary voltage equal to 10 kV and the
sensor rated voltage equal to 20 kV.
i
i
NOTE
When the device with firmware version 2.00/2.10 is upgraded to firmware version 2.20 and above, check
the Primary voltage and Sensor voltage parameters and adapt them accordingly.
Voltage Measurements with Sensors as per IEC 60044-7, IEC 61869-11 and
with Conventional Voltage Sensors
The device can be used to measure voltages with the sensors as per IEC 60044-7, IEC 61869-11 and with
conventional voltage sensors by connecting the sensor outputs to the V
1
, V
2
, and V
3
terminals. The current
inputs (I
1
, I
2
, and I
3
) of the device are connected to the LoPo current sensors in the medium-voltage system.
This function can be selected by configuring the
primary voltage
parameter to 3.25/√ 3 or 100/√ 3.
The following figure shows how the device is connected to the sensors or to the conventional voltage sensors.
[dw_sfcm-volsenIEC, 2, en_US]
Figure 4-19
Voltage Measurement with Sensors as per IEC 60044-7, IEC 61869-11 or with Conventional
Voltage Sensors
4.1.28
4.1.29
Device Functions
4.1 Description
52
SICAM, Feeder Condition Monitor, Manual
E50417-H8940-C580-A4, Edition 03.2019