MiCOM P921/P922/P923 - Schneider - error

Technical GuideP92x/EN FT/H42User GuideMiCOM P921/P922/P923 Page 39/702.6.2 Overvoltage protectionThis function can be configured according to the connection scheme of the VTs:phase-phase (delta connection) or phase-neutral protection (star connection).For this overvoltage protection, the configuration can also be done in order to have:• the highest voltage of each phase will be decisive: select OR for the consideredstage,• each voltage for each phase must be higher than the settable stage: select ANDfor the considered stage.The settings of the voltage thresholds are done in secondary values.The relay will trip according to an inverse characteristic or a definite timecharacteristic for the first stage and according to a definite time characteristic for thesecond and third stage.The inverse characteristic is given by the following formula:Where,t = K / (M - 1)K = Time Multiplier Settingt = operating time in secondsM = Applied input voltage / Relay setting voltage (Vs).To gain access to the “[59] OVERVOLTAGE” submenu from the “PROTECTIONgroup” menu, press followed by or until the desired submenu header isdisplayed.PROTECTION G1 (G2)[59] OVERVOLTAGEHeading of the protection menu (group 1 or group 2). To gainaccess to the menu from the default display press followedby or until the menu is displayed.Heading of the “OVERVOLTAGE” submenu[59] V>=[59] V>=NO130.0 V[59] DELAY TYPE =DMT[59] TMS=1.0[59] tRESET V>=10 ms[59] tV>=40 msDescription: activation of the first overvoltage stageRange: NO / AND / ORIf OR is selected, the first overvoltage stage alarm is emitted ifone phase (at least) is faulty. If AND is selected, this alarmappears when the stage appears on the three phases.Note: if disabled (« NO » selected), all the following messagesare invisible, until « V>> » message.Description: setting of the first overvoltage stageRange: range 57-130V: 5-200V, step =0.1Vrange 220-480V: 20-720V, step = 0.5VDescription: selection of the time delay characteristicRange: definite time (DMT) / inverse definite time (IDMT)Description: time multiplier setting.Range: 0.5 – 100, step = 0.5Note: this message only seen if “IDMT” time delay selectedDescription: reset time for the first overvoltage stageRange: 0 – 100s, step = 0,01sNote: this message only seen if “IDMT” time delay selectedDescription: time delay setting for a definite time curve.Range: 0 – 599s, step = 0.01sNote: this message only seen if “DMT” time delay selected