P12x/EN T/Eb6 - Schneider - error

Technical DataP12x/EN TD/Eb6MiCOM P120/P121/P122/P123 Page 31/5013.1.2 RXIDG Curves (P122/P123 only):RXIDG curves can be selected on P122 & P123 with medium earth current sensitivity(corresponding to Cortec model number P12-B-X---X).The first and second earth thresholds can be selected with dedicated RXIDG curves.The curves available follow the formula :t = 5.8 – 1.35 * ln ( 1/ (k * Is/I))Where:t = tripping timek = coefficient (from 0.3 to 1, by steps of 0.1)IS = value of the programmed threshold (Pick-up value)I = value of measured currentIn order to be compliant with the Netmanagement specifications the relay must be usedwith :− An earth current range 0.01 Ion to 8 Ion− A rated current wiring 1A− A core balanced CT with a ratio 25/1.13.1.3 Reset TimerThe first stage threshold for phase and earth overcurrent protection is provided with a timerhold facility "t Reset".The value that is set for this reset timer corresponds to the minimum time during which thecurrent value needs to be lower than 95% of the phase (or earth) threshold before thecorresponding phase (or earth) time delay is reset.NOTE:There is an exception to this rule when the protection triggers. In fact,in this case, the time delays (tI> and tIe>) are immediately reset.The value of the Reset Timer depends on the type of timer associated to the pick up firstphase (or earth) threshold.Type of timer associated to theReset Timerfirst & second phase (earth)threshold P120, P121 P122, P123DMT 0 ms 0 msRectifier, IDMT IEC or RI 50 ms Settable from 0 to 600 msRXIDG (*) - Settable from 0 to 600 msIDMT IEEE or CO 50 ms Settable from 0 to 600 ms orInverse Time (choice of 5 IEEEcurves)(*) first and second earth threshold onlyReset timer on P122 & P123 relays:The first stage threshold for phase and earth overcurrent protection, negative sequenceovercurrent on P122 and P123 are provided with a timer hold facility "t Reset".It may be set to a definite time value or to an inverse definite minimum time characteristic(IEEE/ANSI curves only). This may be useful in certain applications, for example whengrading with upstream electromechanical overcurrent relays that have inherent reset timedelays.The second and third stage thresholds for the earth fault overcurrent protection only have adefinite time reset.A possible situation where the reset timer may be used is to reduce fault clearance timeswhere intermittent faults occur.