If
No CBPos Check
or
Retrip off
is set, only back-up trip can be
used to check set
IP>
.
10.4.6.2
Checking the residual (earth fault) current operate value
IN> set
below
IP>
M12104-80 v9
Check the low set
IN>
current where setting
FunctionMode
=
Current
and setting
BuTripMode
=
1 out of 4
1.
Apply the fault condition, including START of CCRBRF, with a current just
below set
IN>
.
2.
Repeat the fault condition and increase the current in steps until trip appears.
3.
Compare the result with the set
IN>
.
4.
Disconnect AC and START input signals.
10.4.6.3
Checking the re-trip and back-up times
M12104-93 v11
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
RetripMode
=
CB Pos Check
.
1.
Apply the fault condition, including start of CCRBRF, well above the set
current value. Measure the time from START of CCRBRF.
2.
Check the re-trip
t1
and back-up trip times
t2
and
t3
.
In applicable cases, the back-up trip for multi-phase start
t2MPh
and back-up
trip 2,
t2
and
t3
can also be checked. To check
t2MPh
, a two-phase or three-
phase start shall be applied.
10.4.6.4
Verifying the re-trip mode
M12104-36 v6
Choose the mode below, which corresponds to the actual case.
In the cases below it is assumed that
FunctionMode
=
Current
is selected.
Checking the case without re-trip,
RetripMode = Retrip Off
M12104-107 v7
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 v7
1MRK 505 372-UEN A
Section 10
Testing functionality by secondary injection
Busbar protection REB670 2.2 IEC
97
Commissioning manual
