reset curve type "Def time reset", the reset time depends on the Reset delay timesetting. With the reset curve type "Inverse reset", the reset time depends on the currentduring the drop-off situation. The START output is deactivated when the reset timerhas elapsed.The "Inverse reset" selection is only supported with ANSI or userprogrammable types of the IDMT operating curves. If anotheroperating curve type is selected, an immediate reset occurs during thedrop-off situation.The setting Time multiplier is used for scaling the IDMT operate and reset times.The setting parameter Minimum operate time defines the minimum desired operatetime for IDMT. The setting is applicable only when the IDMT curves are used.The Minimum operate time setting should be used with great carebecause the operation time is according to the IDMT curve, but alwaysat least the value of the Minimum operate time setting. For moreinformation, see the IDMT curves for overcurrent protection sectionin this manual.The timer calculates the start duration value START_DUR, which indicates thepercentage ratio of the start situation and the set operating 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 signal activation ispreselected with the global setting Blocking mode.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.4.1.2.5 Measurement modesThe function operates on three alternative measurement modes: “RMS”, “DFT” and“Peak-to-Peak” . The measurement mode is selected with the Measurement modesetting.1MRS758755 A Section 4Protection functionsREC615 and RER615 229Technical Manual
