5. Disconnect the trip signal(s). Keep the CB closed signal(s).
6. Apply input signal(s), for initiation of CCRBRF (50BF).
7. Arrange disconnection of CB closed signal(s) well before set back-up trip time t2.
8. Verify that back-up trip is not achieved.
9. Disconnect injected AC and BFI_3P input signals.
11.5.9.10 Verifying the caseFunctionMode = Current or CB Pos
M12104-237 v7
To be made only whenFunctionMode = Current or CB Pos is selected. It is suggested to make the tests
in one phase only, or at three-pole trip applications for just three-pole tripping.
Checking the case with fault current above set value Pickup_PH
M12104-241 v8
The operation shall be as in RetripMode = UseFunctionMode.
1. Set FunctionMode = Current or CB Pos.
2. Leave the inputs for CB close inactivated. These signals should not influence.
3. Apply the fault condition, including initiation of CCRBRF (50BF), with current above the set
Pickup_PH value.
4. Check that the re-trip, if selected, and back-up trip commands are achieved.
5. Disconnect injected AC and BFI_3P input signals.
Checking the case with fault current below set value Pickup_BlkCBPos
M12104-281 v11
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 retrip without current check is used, setting
RetripMode = UseFunctionMode Check.
1. Set FunctionMode = Current or CB Pos.
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>BlkCBPos
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 BFI_3P 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>BlkCBPos.
7. Arrange disconnection of CB 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
RetripMode = Always.
9. Disconnect injected AC and BFI_3P input signals.
11.5.9.11 Verifying the external start signal has timed out
GUID-754108D4-E440-4F8F-917B-04579EC1C2C7 v1
1. Set StartMode = FollowStart.
2. Set FunctionMode = Current.
3. Use default value for tStartTimeout = 1.0 s.
4. Use default value for time delay backup trip t2 = 0.150 s.
5. Leave the inputs for CB close inactivated. These signals should not influence.
6. Apply START signal, and after 1.5 s apply the current above the set IPPU value.
7. Check that STALARM signal is set after 1.0 s and backup trip is blocked.
Section 11 1MRK 504 165-UUS Rev. J
Testing functionality by secondary injection
184 Transformer protection RET670
Commissioning manual
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