the customer specification requirements for overcurrent settings of up to 20
xIn.
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/or sensor routine test protocol, and conversions are not
needed.
Figure 22: Example of ABB voltage sensor KEVA 17.5 B21 rating plate
In this example the system phase-to-phase voltage rating is 10 kV. Thus, the
Primary voltage parameter is set to 10 kV. For protection relays with sensor
measurement support, the
Voltage input type is set to "Voltage sensor". The
VT connection parameter is set to the "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
Value
Primary voltage
10 kV
VT connection
Wye
Voltage input type
3=Voltage sensor
Division ratio
10000
3.8
Binary input
3.8.1
Binary input filter time
The filter time eliminates debounces and short disturbances on a binary input. The
filter time is set for each binary input of the merging unit.
1MRS758407 C
Basic functions
SMU615
Technical Manual
61
Summary of Contents for Relion SMU615
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