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4
4.1
4.2
4.2.1
4.2.2
Breaker failure protection (BFP)
Breaker failure protection (BFP)
Prepare the terminal for verification of settings as outlined in
this chapter.
Consider to release used start criteria. The trip is a pulse with a length of 150 ms. Fault condition:
the current in a phase must exceed the set IP> as latest within the set t1 time after the
START/STLN input is activated.
To verify the settings the following fault type should be tested:
•
One for a phase-to-earth fault
The breaker-failure protection should be tested in co-operation with some other functions, and
in particular with the protection and trip functions or via external start.
Verifying the settings
Procedure
1.
Apply the fault condition with a current below set IP>.
2.
Repeat the fault condition and increase the current in step until trip
appears.
3.
Compare the result with the set IP>.
Note: If no I> check is set only back-up trip operate at set IP>.
Verifying the retrip setting
Choose one of the test cases in
Checking the retrip function with retrip set to off
Procedure
1.
Set RetripType = Retrip Off.
2.
Apply the fault condition with current over the set value.
3.
Verify that retrip in phase L1 is not achieved.
Checking the retrip function with current check
Procedure
1.
Set RetripType = I> check.
2.
Apply the fault condition with current over the set value.
3.
Verify that retrip is achieved after t1 that back-up trip is achieved af-
ter t2.
4.2 "Verifying the retrip setting"
Chapter 13
Verifying settings by secondary
section 2 "Preparing for test"
according to valid setting.
injection
in
93
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