The outputs from the above configured SMAI block shall only beused for Overfrequency protection (SAPTOF), Underfrequencyprotection (SAPTUF) and Rate-of-change frequency protection(SAPFRC) due to that all other information except frequency andpositive sequence voltage might be wrongly calculated.21.9 Summation block 3 phase 3PHSUM SEMOD55968-1 v221.9.1 Functionality SEMOD55976-4 v4Summation block 3 phase function 3PHSUM is used to get the sum of two sets ofthree-phase analog signals (of the same type) for those IED functions that mightneed it.21.9.2 Function block SEMOD54885-4 v33PHSUMBLOCKREVROT^G1AI3P*^G2AI3P*AI3PAI1AI2AI3AI4IEC05000441-3-en.vsdxIEC05000441 V3 EN-USFigure 372: 3PHSUM function block21.9.3 Signals SEMOD55989-1 v2PID-6428-INPUTSIGNALS v3Table 605:3PHSUM Input signalsName Type Default DescriptionBLOCK BOOLEAN 0 BlockBLKGR1 BOOLEAN 0 Block input for group 1BLKGR2 BOOLEAN 0 Block input for group 2REVROT BOOLEAN 0 Reverse rotationG1AI3P GROUPSIGNAL- Group 1 three phase analog input from first SMAIG2AI3P GROUPSIGNAL- Group 2 three phase analog input from secondSMAISection 21 1MRK 505 394-UEN ABasic IED functions804 Line differential protection RED650 2.2 IECTechnical manual
