input. A control command to the circuit breaker, either local or remote, also blocksthe autorreclose function via the CBXCBR-selected signal.The circuit breaker availability for the autorreclosure sequence is expressed with thebinary input 4 (X110:6-7) by connecting the input signal to the CB_RDY input. Incase this signal is completely removed from the autorreclose function block withSMT, the function assumes that the breaker is available all the time.The autorreclose sequence in progress indication is connected to the alarm LED 11.Three overvoltage and undervoltage protection stages (PHxPTOV and PHxPTUV)offer protection against abnormal phase voltage conditions. The operation of voltagefunctions is connected to alarm LED 3. A failure in the voltage measuring circuit isdetected by the fuse failure function and the activation is connected to undervoltageprotection functions to avoid faulty undervoltage tripping.GUID-BCEB1C2E-BC64-4E79-8329-A5D9FCD7AB2F V1 ENFigure 54: Overvoltage and undervoltage protectionPositive-sequence undervoltage (PSPTUV) and negative-sequence overvoltage(NSPTOV) protection functions enable voltage-based unbalance protection. Theoperation signals of voltage-sequence functions are connected to alarm LED 3, whichis a combined voltage protection alarm led.1MRS756378 D Section 3REF615 variantsREF615 101Application Manual
