1MAC309294-MB F Section 7Measurement functionsRER620 383Technical ManualSection 7 Measurement functions7.1 Basic measurements7.1.1 FunctionsThe three-phase current measurement function, IA, IB, IC, is used for monitoring andmetering the phase currents of the power system.The three-phase voltage measurement function, VA, VB, VC, is used for monitoring andmetering the phase-to-phase voltages of the power system. The phase-to-ground voltagesare also available in VA, VB, VC.The ground current measurement function, IG, is used for monitoring and metering theground current of the power system.The ground voltage measurement function, VG, is used for monitoring and metering theground voltage of the power system.The sequence current measurement, I1, I2, I0, is used for monitoring and metering thephase sequence currents.The sequence voltage measurement, V1, V2, V0, is used for monitoring and metering thephase sequence voltages.The three-phase power and energy measurement P,SP, E is used for monitoring andmetering the active power P, reactive power Q, apparent power S, power factor PF onindividual phases as well as three phase total and for calculating the accumulated energyseparately on three phase total basis as forward active, reverse active, forward reactive andreverse reactive. P, SP, E calculates these quantities with the fundamental frequencyphasors, that is, the DFT values of the measured phase current and phase voltage signals.The information of the measured quantity is available for the operator both locally inLHMI and remotely to a network control center with communication.7.1.2 Measurement functionalityThe functions can be enabled or disabled with the Operation setting. The correspondingparameter values are Enable and Disable.Some of the measurement functions operate on two alternative measurement modes:“DFT” and “RMS”. The measurement mode is selected with the X Measurement modesetting. Depending on the measuring function if the measurement mode cannot beselected, the measuring mode is “DFT”.
