Verification of single-phase voltage and time delay to trip for Step 1
1. Apply single-phase voltage below the set value Pickup1.
2. Slowly increase the voltage until the PU_ST1 signal appears.
3. Note the trip value and compare it with the set value Pickup1.
The trip value in secondary volts is calculated according to the
following equations:
For phase-to-ground measurement:
sec
100
3
Vpickup VBase VT
VTprim
>
´ ´
ANSIEQUATION2426 V1 EN (Equation 99)
For phase-to-phase measurement:
sec
100
Vpickup VT
VBase
VTprim
>
´ ´
ANSIEQUATION2427 V1 EN (Equation 100)
4. Decrease the voltage slowly and note the reset value.
5. Set and apply about 20% higher voltage than the measured trip value for one phase.
6. Measure the time delay for the TRST1 signal and compare it with the set value.
7. Check the inverse time delay by injecting a voltage corresponding to 1.2 ×
Vpickup>.
8. Repeat the test to check the inverse time characteristic at different over-voltage
levels.
9. Repeat the above described steps for Step 2 of the function.
11.6.2.2 Extended testing
1. The tests above can be repeated for 2 out of 3 and for 3 out of 3 operation mode.
11.6.2.3 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.
Section 11 1MRK 504 165-UUS -
Testing functionality by secondary injection
214 Transformer protection RET670 2.2 ANSI
Commissioning manual
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