to-phase voltages VAB, VBC and VCA. This information about actual VT connection isentered as a setting parameter for the pre-processing block, which will then takeautomatically care about it.10.1.2.2 Base quantities for CVGAPC functionThe parameter settings for the base quantities, which represent the base (100%) for pickuplevels of all measuring stages shall be entered as setting parameters for every CVGAPCfunction.Base current shall be entered as:1. rated phase current of the protected object in primary amperes, when the measuredCurrent Quantity is selected from 1 to 9, as shown in table 35.2. rated phase current of the protected object in primary amperes multiplied by √3(1.732 x Iphase), when the measured Current Quantity is selected from 10 to 15, asshown in table 35.Base voltage shall be entered as:1. rated phase-to-ground voltage of the protected object in primary kV, when themeasured Voltage Quantity is selected from 1 to 9, as shown in table 36.2. rated phase-to-phase voltage of the protected object in primary kV, when themeasured Voltage Quantity is selected from 10 to 15, as shown in table 36.10.1.2.3 Application possibilitiesDue to its flexibility the general current and voltage protection (CVGAPC) function canbe used, with appropriate settings and configuration in many different applications. Someof possible examples are given below:1. Transformer and line applications:• Underimpedance protection (circular, non-directional characteristic) (21)• Underimpedance protection (circular mho characteristic) (21)• Voltage Controlled/Restrained Overcurrent protection (51C, 51V)• Phase or Negative/Positive/Zero Sequence (Non-Directional or Directional)Overcurrent protection (50, 51, 46, 67, 67N, 67Q)• Phase or phase-to-phase or Negative/Positive/Zero Sequence over/undervoltage protection (27, 59, 47)• Special thermal overload protection (49)• Open Phase protection• Unbalance protection2. Generator protection1MRK 505 337-UUS - Section 10Multipurpose protection259Application manual
