Figure 3.1.1-1 Logic Diagram: Directional Overcurrent Element (67) - Siemens Argus 7SR21 Technical Manual

7SR210 & 7SR220 Description of Operation
Minimum Polarising Voltage
The 67 Minimum Voltage setting defines the minimum polarising voltage level. Where the measured polarising
voltage is below this level no directional output is given and operation of protection elements set as directional will
be inhibited. This prevents mal-operation under fuse failure/MCB tripped conditions where noise voltages can be
present.
Figure 3.1.1-1 Logic Diagram: Directional Overcurrent Element (67)
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