EDR-5000
IM02602007E
Directional Features for Measured (IX) Ground Fault Elements 50X/51X
All ground fault elements can be selected as »
Non-directional/Forward/Reverse« operated. This has to be done in the
»
Device Planning« menu.
For the direction detection, it is mandatory that the required voltages exceed
0.35 V and the required currents exceed 10 mA. An exception is the measured
sensitive ground current which has to exceed 1 mA.
Important Definitions
Polarizing Quantity:
This is the quantity that is used as a reference value.
The
polarizing quantity can be selected by
the parameter »
IX Direction Control« in the [System Para/Direction] menu as follows:
»IX 3V0«: The neutral voltage selected by the parameter »3V0 Source« will be used as the
polarizing quantity. The traditional way to polarize a ground fault element is to use neutral
voltage (3V0). The neutral voltage can, however, be either »
measured« or »calculated«. This
can be selected by the parameter »
3V0 Source« in the [System Para/Direction] menu.
»IX Neg«: With this selection, the negative phase sequence voltage and current (Polarizing:
V2/Operating: I2) will be used to detect direction. The monitored current is still the measured
residual current IX.
»IX Dual«: For this method, the negative phase sequence voltage »V2« will be used as
polarizing quantity if »
V2« and »I2« are available, otherwise 3V0 will be used. The operating
quantity is either I2 if »
V2« and »I2« are available, else IX.
The following table gives the User a quick overview of the all possible directional settings.
50X/51X Direction Decision
by Angle Between:
[System Para/
Direction]
The Following Angle
Has to Be Set:
[System
Para/Direction]:
IX Dir Cntrl =
[System
Para/Direction]:
3V0 Source =
Measured ground current and neutral voltage:
IX, 3V0 (measured)
Ground MTA
IX 3V0
Measured
Measured ground current and neutral voltage:
IX, 3V0 (calculated)
Ground MTA
IX 3V0
Calculated
Negative sequence voltage and current
I2, V2
90° + Phase MTA
IX Neg
N.A.
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