1.
Connect the test set for single-phase current injection to the protection
terminals connected to the CT in the power transformer neutral-to-earth circuit.
2.
Increase the injection current and note the operating value of the protection
function.
3.
Check that all trip and start contacts operate according to the configuration logic.
4.
Decrease the current slowly from operate value and note the reset value.
5.
Connect the timer and set the current to twice the operate value.
6.
Switch on the current and note the operate time.
7.
Connect the test set to terminal L1 and neutral of the three-phase current input
configured to REFPDIF. Also inject a current higher than half the
Idmin
setting in the neutral-to-earth circuit with the same phase angle and with
polarity corresponding to an internal fault.
8.
Increase the current injected in L1, and note the operate value. Decrease the
current slowly and note the reset value.
9.
Inject current into terminals L2 and L3 in the same way as in point 7 above
and note the operate and reset values.
10. Inject a current equal to 10% of rated current into terminal L1.
11. Inject a current in the neutral-to-earth circuit with the same phase angle and
with polarity corresponding to an external fault.
12. Increase the current to five times the operating value and check that the
protection does not operate.
13. Finally check that trip information is stored in the event menu.
6.3.2.2
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/Differential/REFPDIF(87,INd)/X:REFPDIF
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.
6.3.3
High impedance differential protection HZPDIF
Prepare the IED for verification of settings as outlined in
Values of the logical signals for HZPDIF are available on the local HMI under
Main menu/Tests/Function status/Differential/HZPDIF(87,IdN)/X:HZPDIF
.
The Signal Monitoring in PCM600 shows the same signals that are available on the
local HMI.
6.3.3.1
Verifying the settings
1.
Connect single-phase or three-phase test set to inject the operating voltage.
The injection shall be on the primary side of the stabilizing resistor.
Section 6
1MRK 504 126-UEN -
Testing functionality
42
Commissioning Manual