condition, the voltage regulation function is not blocked and a lower commandshould be issued from the IED.13.10.3.6 Check the overcurrent block function SEMOD175185-605 v51. Confirm the setting for Iblock in the local HMI under Main menu/Settings/Setting group N/Control/TransformerVoltageControl(ATCC,91)/TR1ATCC:x/TR8ATCC:x/TCCtrl/Iblock2. Confirm the voltage control function response to an applied current above Iblock,by reviewing the settings in the local HMI under Main menu/Settings/Generalsettings/Control/TransformerVoltageControl(ATCC,91)/TR1ATCC:x/TR8ATCC:x/OVPartBk. This condition may cause an alarm or total block ofthe voltage control function to be displayed on the local HMI.3. Inject a current higher than the Iblock setting and confirm the alarm or blockingcondition is present on the local HMI. If an automatic or total blocking conditionoccurs, change the applied secondary voltage and confirm that no tap changecommands are issued from the associated binary outputs. This situation can alsobe confirmed through reviewing the disturbance and service reports on the localHMI.13.10.3.7 Single transformer SEMOD175185-669 v2Load drop compensation SEMOD175185-672 v51. Confirm that OperationLDC is set to Enabled.2. Confirm settings for Rline and Xline.3. Calculate the expected load voltage VL (displayed as a measured value on thelocal HMI) based on secondary injection of transformer secondary voltage (VB =VSet) and rated load current (IL = I1Base), in accordance with equation 111.VL = VB - (Rline + jXline) . ILEQUATION2081-ANSI V2 EN-US (Equation 111)where:VL, IL = Re(IL) + jlm(IL) are complex phase quantitiesWhen all secondary phase-to-ground voltages are available, use the positive-sequence components of voltage and current. By separation of real and imaginaryparts:1MRK 502 073-UUS A Section 13Testing functionality by secondary injectionGenerator protection REG670 2.2 ANSI and Injection equipment REX060, REX061, REX062 263Commissioning manual
