Name Values (Range) Unit Step Default DescriptionU1> 1 - 200 %UB 1 30 Voltage start value (DT & IDMT) in % ofUBase for step 1t1 0.00 - 6000.00 s 0.01 5.00 Definite time delay of step 1t1Min 0.000 - 60.000 s 0.001 5.000 Minimum operate time for inverse curvesfor step 1k1 0.05 - 1.10 - 0.01 0.05 Time multiplier for the inverse time delayfor step 1OperationStep2 OffOn- - On Enable execution of step 2U2> 1 - 100 %UB 1 45 Voltage start value (DT & IDMT) in % ofUBase for step 2t2 0.000 - 60.000 s 0.001 5.000 Definite time delay of step 2Table 145:ROV2PTOV Non group settings (basic)Name Values (Range) Unit Step Default DescriptionGlobalBaseSel 1 - 6 - 1 1 Selection of one of the Global Base Valuegroups9.3.6 Monitored dataTable 146:ROV2PTOV Monitored dataName Type Values (Range) Unit DescriptionULevel REAL - kV Magnitude of measuredvoltage9.3.7 Operation principleTwo step residual overvoltage protection ROV2PTOV is used to detect earth (zerosequence) overvoltages. The ground overvoltage 3U0 is normally computed byadding the input phase voltages. 3U0 may also be input single phase by eithermeasuring directly from a voltage transformer in the neutral of a power transformer,or from a secondary broken delta connection of a transformer with a star-groundedprimary. ROV2PTOV has two steps with separate time delays. If the groundovervoltage remains above the set value for a time period corresponding to the chosentime delay, the corresponding TRIP signal is issued.The time delay characteristic is setable for step 1 and can be either definite or inversetime delayed. Step 2 is always definite time delayed.The voltage related settings are made in percent of the global phase-to-phase basevoltage divided by √3.Section 9 1MRK 504 135-UEN AVoltage protection218Technical manual
