Woodward HighPROTEC - Page 762

Protective Elements
Testing the trip delay inverse time element 46G:
Set a K-value, e. g. K-value = 5
Calculate the resulting tripping time acc. to the Generator unbalance tripping curves or to the following formula
t
trip
=
K
(
I
2
FLA
)
2
– in this example:
t
trip
=
5 s
(0.33)
2
= 46 s
Apply a balanced three-phase current system (nominal currents).
Switch off IA (the threshold value » Threshold« for » I2 Fund.« must be below 33%).
The present current unbalance » I2 Fund.« corresponds with 1/3 of the existing phase current displayed.
Measure if the tripping time corresponds to the calculated tripping delay.
Successful test result:
The measured trip delays are within the permitted deviations/tolerances, specified under Technical Data.
762 MCDGV4 DOK-HB-MCDGV4-2E