ABB Relion SMU615 Technical Manual page 59

1MRS758407 B
SMU615
Technical Manual
Table 34: Example setting values for rogowski sensor
Setting
Primary current
Rated secondary value
Nominal current
Unless otherwise specified, the Nominal Current setting should
always be the same as the Primary Current setting.
If the ratio of the application nominal current I
becomes higher, the rated secondary value needs to be set higher than 46.875 mV/Hz.
Table 35: Maximum range
Application nominal current
(I )
n
...833 A
833...1250 A
1250...2500 A
2500...4000 A
Voltage sensor setting example
The voltage sensor is based on the resistive divider or capacitive divider principle.
Therefore, the voltage is linear throughout the whole measuring range. The output
signal is a voltage, directly proportional to the primary voltage. For the voltage sensor
all parameters are readable directly from its rating plate and conversions are not
needed.
In this example the system phase-to-phase voltage rating is 10 kV. Thus, the Primary
voltage parameter is set to 10 kV. For merging units with sensor measurement support
the Voltage input type is always set to "CVD sensor" and it cannot be changed. The
same applies for the VT connection parameter which is always set to "WYE" type. The
division ratio for ABB voltage sensors is most often 10000:1. Thus, the Division ratio
parameter is usually set to "10000". The primary voltage is proportionally divided by
this division ratio.
Table 36: Example setting values for voltage sensor
Setting
Primary voltage
VT connection
Voltage input type
Division ratio
Value
150 A
5.625 mV/Hz
150 A
n
Rated secondary value with 80 A/
0.150 V at 50 Hz
...31.237 mV/Hz
31.237...46.875 mV/Hz
46.875...93.750 mV/Hz
93.750...150.000 mV/Hz
Value
10 kV
Wye
3=CVD sensor
10000
Section 3
Basic functions
and sensor-rated primary current I
Maximum range
6000%I
n
4000%I
n
2000%I
n
1250%I
n
pr
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