Protective Elements
Signals of the asymmetry module (states of the outputs)
Signal
Description
active
Signal: active
ExBlo
Signal: External Blocking
Blo TripCmd
Signal: Trip Command blocked
ExBlo TripCmd
Signal: External Blocking of the Trip Command
Alarm
Signal: Alarm voltage asymmetry
Trip
Signal: Trip
TripCmd
Signal: Trip Command
Commissioning: Asymmetry Protection
Object to be tested
Test of the asymmetry protection elements.
Necessary means
3-phase AC voltage source
Timer for measuring of the tripping time
Voltmeter
Testing the tripping values (Example)
Set the pickup value for the voltage in the negative phase sequence to 0.5 Vn. Set the tripping delay to 1 s.
In order to generate a negative phase sequence voltage interchange the wiring of two phases (VL2 and VL3).
Testing the trip delay
Start the timer and abrupt change (switch) to 1.5 times of the set tripping value. Measure the trip delay.
Successful test result
The measured threshold values and trip delays comply with those specified in the adjustment list. Permissible
deviations/tolerances can be taken from the Technical Data.
430
MRU4
DOK-HB-MRU4-2E
