4.12.1.2 Function blockGUID-4360928E-C2D8-4978-AB08-E02D3B77E243 V1 ENFigure 546: Function block4.12.1.3 FunctionalityThe three-phase overload protection for shunt capacitor banks function COLPTOCprovides single-phase, two-phase and three-phase protection against overloadscaused by harmonic currents and overvoltages in shunt capacitor banks. The operationof overload and alarm is based on the peak value of the integrated current which isproportional to the voltage across the capacitor.The overload function operates with IDMT characteristic and an alarm functionoperates with DT characteristic.COLPTOC provides undercurrent protection to detect disconnection of the capacitor.COLPTOC has breaker reclosing inhibit feature to enable complete capacitordischarging before breaker reclosing after it has operated.COLPTOC contains blocking functionality. It is possible to block the functionoutputs, timers or the function itself.4.12.1.4 Analog channel configurationCOLPTOC has one analog group input which must be properly configured.Table 950:Analog inputsInput DescriptionI3P Three-phase currentsSee the preprocessing function blocks in this document for thepossible signal sources.Improper analog channel configuration causes a validation error if the analogchannels are not completely configured or they do not match with certain settings. Fortroubleshooting, check the contents of this chapter and also the preprocessing blocksin this document. The configuration can be written to the protection relay once themismatch is corrected.Section 4 1MRS759142 CProtection functions1010 REX640Technical Manual
