1.
Set
RetripMode = Retrip Off.
2.
Apply the fault condition, including start of CCRBRF, well above the set current value.
3.
Verify that no re-trip, but back-up trip is achieved after set time.
Checking the re-trip with current check,
RetripMode = CB Pos Check
M12104-48 v6
1.
Set
RetripMode = CB Pos Check.
2.
Apply the fault condition, including start of CCRBRF, well above the set current value.
3.
Verify that re-trip is achieved after set time
t1 and back-up trip after time t2
4.
Apply the fault condition, including the start of CCRBRF, with the current below the set
current value.
5.
Verify that no re-trip, and no back-up trip is obtained.
Checking re-trip without current check
M12104-58 v8
1.
Set
RetripMode = No CBPos Check.
2.
Apply the fault condition, including start of CCRBRF, well above the set current value.
3.
Verify that re-trip is achieved after the set time
t1, and the back-up trip after time t2.
4.
Apply the fault condition, including start of CCRBRF, with current below set current value.
5.
Verify that re-trip is achieved after set time
t1, but no back-up trip is obtained.
12.5.9.5
Verifying the back-up trip mode
M12104-146 v5
In the cases below it is assumed that
FunctionMode = Current is selected.
Checking that back-up tripping is not achieved at normal CB tripping
M12104-150 v7
Use the actual tripping modes. The case below applies to re-trip with current check.
1.
Apply the fault condition, including start of CCRBRF, with phase current well above set
value
IP>.
2.
Interrupt the current, with a margin before back-up trip time,
t2. It may be made at issue
of re-trip command.
3.
Check that re-trip is achieved, if selected, but no back-up trip is obtained.
The normal mode
BuTripMode = 1 out of 3 should have been verified in the tests above. In
applicable cases the modes
1 out of 4 and 2 out of 4 can be checked. Choose the mode below,
which corresponds to the actual case.
Checking the case
BuTripMode = 1 out of 4
M12104-165 v6
It is assumed that the earth-fault current setting
IN> is below phase current setting IP>.
1.
Set
BuTripMode = 1 out of 4.
2.
Apply the fault condition, including start of CCRBRF, with one-phase current below set
IP> but above IN>. The residual earth-fault should then be above set IN>.
3.
Verify that back-up trip is achieved after set time. If selected, re-trip should also appear.
4.
Disconnect AC and START input signals.
Checking the case
BuTripMode = 2 out of 4
M12104-179 v7
The earth-fault current setting
IN> may be equal to or below phase-current setting IP>.
1.
Set
BuTripMode = 2 out of 4.
2.
Apply the fault condition, including start of CCRBRF, with one-phase current above set
IP> and residual (earth fault) above set IN>.
3.
Verify that back-up trip is achieved after set time. If selected, re-trip should also appear.
Section 12
1MRK 502 067-UEN B
Testing functionality by secondary injection
166
Commissioning manual
