Woodward SEG HighPROTEC MRA4, Device Manual

Page: 388 / 510

PQS – Power Protection Module [ANSI 32, 37]
Q<
Testing the threshold values (Example, Threshold 0.3 Qn)
•
Feed rated voltage and 0.9 times rated current (90° phase shift) to the
measuring inputs of the relay (PF=0).
•
The measured values for the active power „Q“ must show a positive
algebraic sign.
•
Set the tripping threshold (e.g. 0.3 Qn).
•
In order to test the tripping thresholds feed 0.5 times rated current to the
measuring inputs of the relay. Reduce the current slowly until the relay
picks up. Ensure that the angle between current and voltage remains
constant. Compare the tripping value to the parameterized.
Testing the tripping delay (Example, Threshold 0.3 Qn)
•
Feed rated voltage and 0.9 times rated current (90° phase shift) to the
measuring inputs of the relay (PF=0).
•
The measured values for the active power „Q“ must show a positive
algebraic sign.
•
Set the tripping threshold (e.g. 0.3 Qn).
•
In order to test the tripping delay feed 0.5 times rated current to the
measuring inputs of the relay. Increase the current with an abrupt change
to 0.2 In. Ensure that the angle between current and voltage remains
constant. Measure the tripping delay at the output of the relay.
Successful test result
The measured total tripping delays or individual tripping delays, threshold values
and fallback ratios correspond with those values, specified in the adjustment list.
Permissible deviations/tolerances can be found under Technical Data.
Page 388 EN MRA4 04/09