Figure. 5.2.2. - 14. Example connection with three line to neutral voltages and zero sequence voltage connected. 3LN+U4 mode
has to be selected. U4 channel has to be set as U0.
Initial data of the connection and the ratings are presented in following table.
Table. 5.2.2. - 26. Initial data of previous example connection.
Phase voltage VT:
VT primary 20000V
VT secondary 100V
Zero sequence voltage VT:
U4 VT primary 20000V
U4 VT secondary 100V
Zero sequence voltage is connected similar way with Line to neutral voltages (+U0).
In case of incorrect wiring all polarities can be switched individually by 180 degrees in IED.
If voltage based protection is used the supervised voltage may be based on line to line –or line to earth
voltages. This selection is completed in each protection stage menu separately.
Voltage protection is based on nominal voltage. If 20000V is set to be the nominal voltage this equals
100% setting in voltage based protection functions. 120% trip setting in overvoltage stage equals to
24000V on primary level so 20% increase in this case would be 4000V.
AQ-F255
Instruction manual
Version: 2.00
27
© Arcteq Relays Ltd