How to read the relay protection action time
The core of the action time test lies in measuring the time interval that the relay protection device takes from receiving the fault signal to issuing the tripping command. Direct voltage application method : Directly apply an action voltage and action current to the protection, and ensure that the phase angle between the voltage and current is within the action range. The zone1 time delay (Z1PD & Z1GD) is generally set to zero, giving instantaneous operation. Direction: Forward Typically required zone 2 reach impedances = 100% line impedances. Functions to give a desired amount of time delay before or after any point of operation in a switching sequence or protective relay system.
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