Question Why does the Sepam Series 20, 40 and 80 Relay not display waveforms for all phases of current / voltage?
When certain variables are calculated rather than acquired (measured) by Sepam, the waveform associated to those variables is not available. Those variables are calculated by a software program, based on the "phasors" derived from signal processing ("sin/cos" filter). For those variables, "not valid" appears in the related field in the disturbance recording file. This may occur for I2, Ir, Vr, U32, U13, according to the set-up. See the example below.