see the IDMT curves for overvoltage protection section in thismanual.The Timer calculates the start duration value START_DUR, which indicates thepercentage ratio of the start situation and the set operation time. The value is availablein the Monitored data view.Blocking logicThere are three operation modes in the blocking function. The operation modes arecontrolled by the BLOCK input and the global setting in Configuration/System/Blocking mode which selects the blocking mode. The BLOCK input can be controlledby a binary input, a horizontal communication input or an internal signal of theprotection relay's program. The influence of the BLOCK input signal activation ispreselected with the global Blocking mode setting.The Blocking mode setting has three blocking methods. In the "Freeze timers" mode,the operation timer is frozen to the prevailing value, but the OPERATE output is notdeactivated when blocking is activated. In the "Block all" mode, the whole function isblocked and the Timers are reset. In the "Block OPERATE output" mode, the functionoperates normally but the OPERATE output is not activated.The “Freeze timers” mode of blocking has no effect during the inversereset mode.4.4.1.5 Timer characteristicsThe operating curve types supported by PHPTOV are:Table 411:Timer characteristics supported by IDMT operate curve typesOperating curve type(5) ANSI Def. Time(15) IEC Def. Time(17) Inv. Curve A(18) Inv. Curve B(19) Inv. Curve C(20) Programmable4.4.1.6 ApplicationOvervoltage in a network occurs either due to the transient surges on the network ordue to prolonged power frequency overvoltages. Surge arresters are used to protect thenetwork against the transient overvoltages, but the relay's protection function is usedto protect against power frequency overvoltages.Section 4 1MRS758755 AProtection functions410 REC615 and RER615Technical Manual
