9.
Simultaneously disconnect all the three-phase voltages from the IED.
No TRIP signal should appear.
10. Reset the VTSU binary input.
11.
Inject the measured voltages at rated values for at least set
tRestore time.
12.
Activate the BLOCK binary input.
13. Simultaneously disconnect all the three-phase voltages from the IED.
No TRIP signal should appear.
14. Reset the BLOCK binary input.
12.6.7.2
Completing the test
SEMOD175023-47 v4
Continue to test another function or end the test by changing the
TestMode setting to Off.
Restore connections and settings to their original values, if they were changed for testing
purposes.
12.7
Frequency protection
SEMOD53547-1 v1
12.7.1
Underfrequency protection SAPTUF
M16289-2 v6
Prepare the IED for verification of settings as outlined in section
in this chapter.
12.7.1.1
Verifying the settings
M16289-15 v3
Verification of START value and time delay to operate
M16289-17 v6
1.
Check that the IED settings are appropriate, for example the START value and the time
delay.
2.
Supply the IED with three-phase voltages at their rated values.
3.
Slowly decrease the frequency of the applied voltage, until the START signal appears.
4.
Note the operate value and compare it with the set value.
5.
Increase the frequency until rated operating levels are reached.
6.
Check that the START signal resets.
7.
Instantaneously decrease the frequency of the applied voltage to a value about 1% lower
than the operate value (a step change more than 2% will increase the time delay).
8.
Measure the time delay of the TRIP signal, and compare it with the set value. Note that
the measured time consists of the set value for time delay plus minimum operate time of
the start function (80 - 90 ms).
Extended testing
M16289-31 v5
1.
The test above can be repeated to check the time to reset.
2.
The tests above can be repeated to test the frequency dependent inverse time
characteristic.
Verification of the low voltage magnitude blocking
M16289-39 v7
1.
Check that the IED settings are appropriate, for example the
StartFrequency, UMin , and
the
tDelay.
2.
Supply the IED with three-phase voltages at rated values.
3.
Slowly decrease the magnitude of the applied voltage, until the BLKDMAGN signal
appears.
4.
Note the voltage magnitude value and compare it with the set value
UMin.
1MRK 502 067-UEN B
Section 12
Testing functionality by secondary injection
193
Commissioning manual
