11.3.2.1 Verifying the settings
1. Connect single-phase or three-phase test set to inject the operating voltage. The
injection is done across the measuring branch.
The required trip and alarm voltage, as well as the used stabilizing
resistance value must be set in the function. Note as well that used
CT input in the IED must have ratio set as 1:1. This is essential for
the measurement of the expected value. Normally a slightly higher
operating value is no problem as the sensitivity is not influenced
much.
2. Increase the voltage and make note of the trip value Pickup. This is done by manual
testing and without trip of the test set.
3. Connect the trip contact to the test set to stop the test set for measurement of trip
times below.
4. Reduce the voltage slowly and make note of the reset value. The reset value must be
high for this function.
5. Check the operating time by injecting a voltage corresponding to 1.2 ˣ Pickup level.
Make note of the measured trip time.
6. If required, verify the trip time at another voltage. Normally 2 ˣ Pickup is selected.
7. If used, measure the alarm level operating value. Increase the voltage and make note
of the trip value AlarmPickup. This is done with manual test and without trip of the
test set.
8. Measure the operating time on the alarm output by connecting the stop of the test set
to an output from tAlarm. Inject a voltage 1.2 ˣ AlarmPickup and measure the alarm
time.
9. Check that trip and alarm outputs trip according to the configuration logic.
10. Finally check that pickup and alarm information is stored in the event menu and if
a serial connection to the SA is available verify that the correct and only the required
signals are presented on the local HMI and on the SCADA system.
Information on how to use the event menu is found in the operator's
manual.
11.3.2.2 Completing the test
Continue to test another function or end the test by changing the TESTMODE setting to
Disabled. Restore connections and settings to their original values, if they were changed
for testing purposes.
1MRK 504 165-UUS - Section 11
Testing functionality by secondary injection
Transformer protection RET670 2.2 ANSI 109
Commissioning manual
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