EDR-5000
IM02602007E
Protective Elements
Directional Feature – Phase Current
All 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.
For the case, that the voltage drops below 0.35 V, the last angle between the operating and
polarizing quantity will be used for the directional detection.
Overcurrent protection elements, time inverse or instantaneous or time delay, etc, can trip in a specified fault current
direction. When the trip direction is set to »
Non-directional«, the directon detection takes no effect. When it is set to
»
Forward«, a trip is only permitted in the forward direction where fault current lies within ± 90° around the maximum
torque angle »
Phase MTA«. When it is set to »Reverse«, a trip is only permitted in reverse direction where fault current
lies within ± 90° around the opposite of the maximum torque angle.
In the case of a 3-phase nearly zero voltage fault, the memorized
voltage, or prefault voltages, is used to establish the
correct fault direction.
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