6.4.6.3
Checking the re-trip and back-up times
The check of the set times can be made in connection with the check of operate
values above.
Choose the applicable function and trip mode, such as
FunctionMode
=
Current
and setting
RetripMode
=
No
CBPos. Check as set under
Main menu/Settings/
IED Settings/Current/CCRBRF(50BF)/1:CCRBRF
.
1.
Apply the fault condition, including start of CCRBRF, well above the set
current value. Measure time from START of CCRBRF.
2.
Check the re-trip
t1
and back-up trip times
t2
.
3.
Disconnect AC and START input signals.
6.4.6.4
Verifying the re-trip mode
Choose the mode below, which corresponds to the actual case.
In the cases below it is assumed that
FunctionMode
=
Current
as set under
Main
menu/Settings/IED Settings/Current/CCRBRF(50BF)/1:CCRBRF
.
Checking the case without re-trip,
RetripMode = Retrip Off
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.
4.
Disconnect AC and START input signals.
Checking the re-trip with current check,
RetripMode = CB Pos Check
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 start of CCRBRF, with current below set
current value.
5.
Verify that no re-trip, and no back-up trip is obtained.
6.
Disconnect AC and START input signals.
Checking re-trip without current check,
RetripMode = No CBPos Check
1.
Set
RetripMode
=
No CBPos Check
.
2.
Apply the fault condition, including start of CCRBRF, without any current.
3.
Verify that re-trip is achieved after set time
t1
, and back-up trip after time
t2
.
1MRK 504 126-UEN -
Section 6
Testing functionality
51
Commissioning Manual