Section 11 Multipurpose protection11.1 General current and voltage protection CVGAPC11.1.1 IdentificationFunction description IEC 61850identificationIEC 60617identificationANSI/IEEE C37.2device numberGeneral current and voltage protection CVGAPC 2(I>/U<) -11.1.2 FunctionalityThe protection module is recommended as a general backup protection with manypossible application areas due to its flexible measuring and setting facilities.The built-in overcurrent protection feature has two settable current levels. Both ofthem can be used either with definite time or inverse time characteristic. Theovercurrent protection steps can be made directional with selectable voltagepolarizing quantity. Additionally they can be voltage and/or current controlled/restrained. 2nd harmonic restraining facility is available as well. At too low polarizingvoltage the overcurrent feature can be either blocked, made non directional or orderedto use voltage memory in accordance with a parameter setting.Additionally two overvoltage and two undervoltage steps, either with definite time orinverse time characteristic, are available within each function.The general function suits applications with underimpedance and voltage controlledovercurrent solutions. The general function can also be utilized for generatortransformer protection applications where positive, negative or zero sequencecomponents of current and voltage quantities are typically required.Additionally, generator applications such as loss of field, inadvertent energizing,stator or rotor overload, circuit breaker head flash-over and open phase detection arejust a few of possible protection arrangements with these functions.11.1.2.1 Inadvertent generator energizationWhen the generator is taken out of service, and non-rotating, there is a risk that thegenerator circuit breaker flashes over or is closed by mistake.1MRK502052-UEN B Section 11Multipurpose protection565Technical manual
