For example, if the inverse time curve A is selected, the tripsignals TR1 and TRIP operate after a time corresponding to theequation:t s kUU( ) =− < 11 1IECEQUATION2428 V1 EN (Equation 22)where:t(s) Operate time in secondsk1 Settable time multiplier of the function for step 1U Measured voltageU1< Set start voltage for step 1For example, if the measured voltage jumps from the rated value to 0.8 times theset start voltage level and time multiplier k1 is set to 0.05 s (default value), thenthe TR1 and TRIP signals operate at a time equal to 0.250 s ± tolerance.10. The test above can be repeated to check the inverse time characteristic atdifferent voltage levels.11. Repeat the above-described steps for Step 2 of the function.Extended testingThe tests above can be repeated for 2 out of 3 and for 3 out of 3 operation mode.10.5.1.2 Completing the testContinue to test another function or end the test by changing the TestMode setting toOff. Restore connections and settings to their original values, if they were changed fortesting purposes.10.5.2 Two step overvoltage protection OV2PTOVPrepare the IED for verification of settings outlined in section "Preparing the IED toverify settings".10.5.2.1 Verifying the settingsVerification of single-phase voltage and time delay to operate for Step11. Apply single-phase voltage below the set value U1>.2. Slowly increase the voltage until the ST1 signal appears.3. Note the operate value and compare it with the set value U1>.1MRK 511 360-UEN A Section 10Testing functionality by secondary injectionBay control REC670 2.1 IEC 119Commissioning manual
