EDR-3000 IM02602003E
Testing the threshold values
Configure minimum »
%(I2/I1)«
setting (2%) and an arbitrary threshold value »
Threshold«
(I2 Fund.).
For testing the threshold value, a current has to be fed to phase A which is lower than three times the adjusted
threshold value »
Threshold«
(I2 Fund.).
Feeding only phase A results in »
%(I2/I1) = 100%«
, so the first condition »
%(I2/I1) >= 2%«
is always fulfilled.
Now increase the phase A current until the relay is activated.
Testing the dropout ratio of the threshold values
Having tripped the relay in the previous test, now decrease the phase A current. The dropout ratio must not be higher
than 0.97 times the threshold value.
Testing %(I2/I1)
Configure minimum threshold value »
Threshold«
(I2 Fund.) (0.01 x In) and set »
%(I2/I1)«
greater or equal to 10%.
Apply a balanced three-phase current system (nominal currents). The measuring value of »
%(I2/I1)«
should be 0%.
Now increase the phase A current. With this configuration, the threshold value »
Threshold«
(I2 Fund.) should be
reached before the value »
%(I2/I1)«
reaches the set »
%(I2/I1)«
ratio threshold.
Continue increasing the phase 1 current until the relay is activated.
Testing the dropout ratio of %(I2/I1)
Having tripped the relay in the previous test, now decrease the phase A current. The dropout of »
%(I2/I1)«
has to be
1% below the »
%(I2/I1)«
setting.
Successful test result:
The measured trip delays, threshold values, and dropout ratios are within the permitted deviations/tolerances, specified
under Technical Data.
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