Sepam - HV/MV Protection and control units (ENG) - Trinet

Commissioning, settingEarth fault current is measured:c by a CSH core balance CT through which 3 phaseconductors pass and which directly detects the sumof the 3 currents. This solution is the most accurateone,c by a 1A or 5A current transformer, using a CSH30interposing ring CT which acts as an adapter.c by a core balance CT with a ratioof 1/n (50 i n i 1500) using the ACE 990 interface.c by the phase CTs. The measurement is obtainedby taking the internal vector sum of the three phasecurrents.It becomes falsified when the CTs are saturated.Saturation may be due either to overcurrent or to thepresence of a DC component in a transformer inrushcurrent or in a phase-to-phase fault current.Check:c the connections,c the positions of the microswitches SW associatedwith the current inputs,c the general parameters in the status menu.Set the following:c type of time delay,v definite time DT,v IDMT: standard inverse time SIT,very inverse time VIT, extremely inverse time EIT,ultra inverse time UIT.c Iso current: Iso is set in rms, amps or kiloamps.The 999 kA setting may be used to inhibit theprotection: all the outputs are set to 0.c T time delay:v DT: T is the operation time delay,v SIT, VIT, EIT, UIT: T is the operation time delayat 10 Iso.c taking into account of harmonic 2 restraint.SensorsEarth fault Io protection is related to the currentsconnected to the following connectors:current sensor connector1A or 5A CT2BCSH2ACSP2L1, 2L2, 2L3CT + CSH302Acore bal. CT + ACE 990 2AEarth fault Io’ protection is related to the currentsconnected to the following connectors:current sensor connector1A or 5A CT3BCSH3ACSP3L1, 3L2, 3L3CT + CSH303Acore bal. CT + ACE 990 3ACharacteristicscurvesettingIso set pointdefinite time settingIDMTdefinite, inverse, very inv., ext. Inv., ultra inv.using CT sumwith CSH core bal. CT2 A rating inputwith CSH core bal. CT30 A rating inputwith CT + CSH300.05 Ino i Iso i 10 Ino (1) expressed in amps0.05 In to 10 In0.1 A to 20 A1.5 A to 300 A0.05 In i Iso i 10 In (0.1 A min.)with core bal. CT + ACE 990 0.05 Ino i Iso i 10 Ino (1) (0.1 A min.)using CT sumwith CSH core bal. CT2 A rating inputwith CSH core bal. CT30 A rating inputCT + CSH300.05 Ino i Iso i Ino (1) expressed in amps0.5 In at In0.1 A to 20 A1.5 A to 30 A0.05 In i Iso i 1 In (0.1 A min.)with core bal. CT + ACE 990 0.05 Ino i Iso i Ino (1) (0.1 A min.)resolution0.1 A or 1 digitaccuracy (2 ) ±5%inhibition999 kAdrop out/pick-up ratio(93.5 ±5)% for Iso > 0.1 InoT time delaysetting definite time 50 ms i T i 655 sIDMT100 ms i T i 12.5 sresolution10 ms or 1 digitaccuracy (2) definite time±2% or +25 msIDMTclass 5 or +25 ms:±12.5% at 2 Is±7.5%, or from 0 to +25 ms at 5 Is±5%, or from 0 to +25 ms at 10 Iso±5%, or from 0 to +25 ms at 20 Isotaking into accountof harmonic 2 restraintF08X, F09Ysettingyes / nocharacteristic times F08X, F09Y F06X, F07Yinstantaneous < 40 ms < 85 mstripping time 30 ms (typical) 50 ms (typical)instantaneous < 4 ms < 85 mstripping time 30 ms (typical) 50 ms (typical)time-delayed tripping time according to time delaymemory time < 30 ms < 65 msfault recognition time < 30 ms < 65 msreset time < 45 ms < 85 msoutputs available for control logicinstantaneous F06X/1, F07Y/1 1 i X i 4 1 i Y i 2F08X/1, F09Y/1time-delayed F06X/2, F07Y/2 1 i X i 4 1 i Y i 2F08X/2, F09Y/2(1)Ino = In if the sum of the three phase currents is used for the measurementIno = sensor rating if the measurement is taken by a CSH core balance CT.Ino = In of the CT if the measurement is taken by a 1A or 5A current transformer.Ino = core balance CT rating if the measurement is taken by a core balance CT other than CSH.(2)in reference conditions (IEC 60255-6).Protection functions2/11