• Definite time delay or Inverse Time Overcurrent TOC/IDMT delay for bothsteps• Second harmonic supervision is available in order to only allow operation ofthe overcurrent stage(s) if the content of the second harmonic in themeasured current is lower than pre-set level• Directional supervision is available in order to only allow operation of theovercurrent stage(s) if the fault location is in the pre-set direction (Forwardor Reverse). Its behavior during low-level polarizing voltage is settable(Non-Directional,Block,Memory)• Voltage restrained/controlled feature is available in order to modify the pick-up level of the overcurrent stage(s) in proportion to the magnitude of themeasured voltage• Current restrained feature is available in order to only allow operation of theovercurrent stage(s) if the measured current quantity is bigger than the setpercentage of the current restrain quantity.2. Two undercurrent steps with the following built-in features:• Definite time delay for both steps3. Two overvoltage steps with the following built-in features• Definite time delay or Inverse Time Overcurrent TOC/IDMT delay for bothsteps4. Two undervoltage steps with the following built-in features• Definite time delay or Inverse Time Overcurrent TOC/IDMT delay for bothstepsAll these four protection elements within one general protection function worksindependently from each other and they can be individually enabled or disabled.However it shall be once more noted that all these four protection elements measureone selected current quantity and one selected voltage quantity (see table 49 andtable 50). It is possible to simultaneously use all four-protection elements and theirindividual stages. Sometimes in order to obtain desired application functionality it isnecessary to provide interaction between two or more protection elements/stageswithin one CVGAPC function by appropriate IED configuration (for example, deadmachine protection for generators).12.1.2.1 Current and voltage selection for CVGAPC function SEMOD53443-6 v3CVGAPC function is always connected to three-phase current and three-phase voltageinput in the configuration tool, but it will always measure only the single current andthe single voltage quantity selected by the end user in the setting tool (selected currentquantity and selected voltage quantity).Section 12 1MRK 504 163-UUS AMultipurpose protection644 Transformer protection RET670 2.2 ANSIApplication manual
