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.
4.
Apply the fault condition, including start of CCRBRF, with at least one-phase
current below set
IP>
and residual (earth fault) above set
IN>
. The current
may be arranged by feeding three- (or two-) phase currents with equal phase
angle (I0-component) below
IP>
, but of such value that the residual (earth
fault) current (3I
0
) will be above set value
IN>
.
5.
Verify that back-up trip is not achieved.
6.
Disconnect AC and START input signals.
10.4.6.6
Verifying instantaneous back-up trip at CB faulty condition
M12104-197 v7
Applies in a case where a signal from CB supervision function regarding CB being
faulty and unable to trip is connected to input CBFLT.
1.
Repeat the check of back-up trip time. Disconnect current and START input
signals.
2.
Activate the input CBFLT. The output CBALARM (CB faulty alarm) should
appear after set time
tCBAlarm
. Keep the input activated.
3.
Apply the fault condition, including start of CCRBRF, with current above set
current value.
4.
Verify that back-up trip is obtained without intentional delay, for example
within 20ms from application of start.
10.4.6.7
Verifying the function mode
Current/Contact
M12104-237 v6
To be made only when
FunctionMode
=
Current/Contact
is selected. It is suggested
to make the tests in one phase only, or at three-phase trip applications for just three-
phase tripping.
Checking the case with fault current above set value
IP>
M12104-241 v7
The operation shall be as in
FunctionMode
=
Current
.
1.
Set
FunctionMode
=
Current/Contact
.
2.
Leave the inputs for CB close inactivated. These signals should not influence.
3.
Apply the fault condition, including the start of CCRBRF, with the current
above the set
IP>
value.
4.
Check that the re-trip, if selected, and back-up trip commands are achieved.
1MRK 505 372-UEN A
Section 10
Testing functionality by secondary injection
Busbar protection REB670 2.2 IEC
99
Commissioning manual
