7.
Arrange disconnection of BC 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 “Re-trip without current check”.
9.
Disconnect injected AC and START input signals.
6.3.7.8
Completing the test
Continue to test another function or end the testing by setting the parameter
TestMode
to
Off
under
Main menu/Tests/IED test mode/1:TESTMODE
. If
another function is tested, then set the parameter
Blocked
to
No
under
Main menu/
Tests/Function test modes/Current/CCRBRF(50BF)/X:CCRBRF
for the
function, or for each individual function in a chain, to be tested next. Remember to
set the parameter
Blocked
to
Yes
, for each individual function that has been tested.
6.3.8
Stub protection STBPTOC
Prepare the IED for verification of settings as outlined in
Logical signals for STBPTOC protection are available on the local HMI
under
Main menu/Tests/Function status/Current/STBPTOC(50STB)/
1:STBPTOC/Inputs or Outputs
Values of the logical signals for STBPTOC are available on the local HMI under
Main menu/Tests/Function status/Current/STBPTOC(50STB,I>)/
1:STBPTOC
. The Signal Monitoring in PCM600 shows the same signals that are
available on the local HMI.
6.3.8.1
Measuring the operate limit of set values
1.
Check that the input logical signals BLOCK and RELEASE and the output
logical signal TRIP are all logical zero.
2.
Activate the input RELEASE on the STBPTOC function block
3.
For a short while inject a current (fault current) in one phase to about 110% of
the set operating current, and switch the current off.
Observe to not exceed the maximum permitted overloading of the current
circuits in the IED.
4.
Switch the fault current on and measure the operating time of STBPTOC.
Use the TRIP signal from the configured binary output to stop the timer. The
operation should be instantaneously.
5.
Activate the input BLOCK on the STBPTOC function block.
6.
Switch on the fault current (110% of the setting).
No TRIP signal should appear.
7.
Switch off the fault current.
8.
For a short while inject a current (fault current) in same phase to about 90%
of the set operating current, and switch the current off.
Section 6
1MRK 511 248-UEN -
Testing functionality
54
Commissioning Manual
