EDR-5000
IM02602007E
Commissioning: 81R Rate of Change (df/dt)
Object to be tested:
All frequency protection stages that are projected as df/dt.
Necessary means:
Three-phase voltage source and
Frequency generator that can generate and measure a linear, defined rate of change of frequency.
Procedure:
Testing the threshold values
Keep on increasing the rate of change of frequency until the respective element is activated and
Note the value.
Testing the trip delay
Set the test voltage to nominal frequency:
Now apply a step change (sudden change) that is 1.5 times the setting value (example: apply 3 Hz per second if
the setting value is 2 Hz per second); and
Measure the tripping time at the relay output. Compare the measured tripping time to the configured tripping
time.
Successful test result:
Permissible deviations/tolerances and dropout ratios can be taken from the Technical Data.
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