Checking the case with fault current below set value
Pickup_BlkCont
The case shall simulate a case where the fault current is very low and operation will
depend on CB position signal from CB auxiliary contact. It is suggested that re-trip
without current check is used, setting RetripMode = No CBPos Check.
1. Set FunctionMode = Current&Contact.
2. Apply input signal for CB closed to relevant input or inputs 52a_A (B or C)
3. Apply the fault condition with input signal(s) for initiation of CCRBRF (50BF). The
value of current should be below the set value Pickup_BlkCont
4. Verify that phase selection re-trip (if selected) and back-up trip are achieved after set
times. Failure to trip is simulated by keeping the signal(s) CB closed activated.
5. Disconnect the AC and the INITIATE signal(s). Keep the CB closed signal(s).
6. Apply the fault and the initiation again. The value of current should be below the set
value Pickup_BlkCont.
7. Arrange disconnection of BC closed signal(s) well before set back-up trip time t2. It
simulates a correct CB tripping.
8. Verify that back-up trip is not achieved. Re-trip can appear for example, due to
selection “Re-trip without current check”.
9. Disconnect injected AC and INITIATE input signals.
6.3.9.8 Completing the test
Continue to test another function or end the testing by setting the parameter TestMode to
Disabled under Main menu/Tests/IED test mode/TESTMODE:1. If another function is
tested, then set the parameter Blocked to No under Main menu/Tests/Function test
modes/Current/CCRBRF(50BF)/CCRBRF:X for the function, or for each individual
function in a chain, to be tested next. Remember to set the parameter Blocked to Yes, for
each individual function that has been tested.
6.3.10 Breaker failure protection, phase segregated activation and
output CSPRBRF (50BF)
Prepare the IED for verification of settings as outlined in
5.1 "Preparing the IED to verify
settings".
Values of the logical signals for CSPRBRF (50BF) are available on the local HMI under
Main menu/Tests/Function status/Current/CSPRBRF(50BF)/CSPRBRF:1. The
Signal Monitoring in PCM600 shows the same signals that are available on the local HMI.
Breaker failure protection, phase segregated activation and output CSPRBRF
(50BF)should normally be tested in conjunction with some other function that provides an
initiate signal. An external INITATE signal can also be used.
Section 6 1MRK 505 293-UUS A
Testing functionality
64
Commissioning manual
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