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 accurate one,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 aresaturated. Saturation may be due either toovercurrent or to the presence of a DC component ina transformer inrush current or in a phase-to-phasefault current.Residual voltage is measured by:c 3 voltage transformers. The measurement isobtained by taking the internal vector sum of the threephase voltages,c 3 voltage transformers with secondary windingsconnected in an open delta arrangement.Check:c the connections,c the positions of the microswitches SW1 associatedwith the current and voltage inputs,c the general parameters in the status menu.Set the following:c Iso current:Iso is set in rms, amps or kiloamps.The 999 kA setting may be used to inhibitthe protection: all the outputs are set to 0.c sector:v 83° by default,v 86° for precision sensors.c Vso residual voltage:Vso is set in rms, volts or kilovolts.Recommended setting: the Vso setting must begreater than the residual voltage detected when thereare no earth faults, due to system dissymmetry andmeasuring chain inaccuracy,c T time delayT is the operation time delay,c Tmem time delayTmem is the time for which the set point overruninformation is memorized after the fault hasdisappeared.Recommended setting: in the range of 250 ms.* available as of version 9802 SFT2800.CharacteristicsIso set pointsettingresolution0.05Ino i Iso i 10Ino (2) expressed in ampsusing CT sum0.05In to 10Inwith CSH core bal. CT2 A rating 0.1 A to 20 Awith CSH core bal. CT30 A rating 1.5 A to 300 Awith CT + CSH30 0,05 In i Iso i 10 In (0.1 A min)with core bal. CT+ ACE 990 0.05 Ino i Iso i 10 Ino (2) (0.1 A min.)accuracy (1) ±5%inhibition0.1 A or 1 digit999 kAdrop out/pick-up ratio (93.5 ±5)%sectorsetting ±83°, ±86°accuracy (1) ±2°Vso set pointvalueaccuracyT time delay and Tmem/ memory timesettingaccuracy (1)resolutionϕ measurement0.02Un i Vso i 0.8Un expressed in volts±2% or 0.005Un50 ms i T i 655 s±2% or +25 ms10 ms or 1 digitmeasurement range 0° to 359°accuracy (1) ±2°resolution 1°characteristic timesinstantaneous tripping timetime delayed tripping timememory timefault recognition timereset time< 65 msTTmem10 ms < t < 40 ms< Tmem + 35 msoutputs available for program logicinstantaneous F48X/1 for normal zone 1 i X i 2F48X/3 for inverse zonetime delayed F48X/2 for normal zone 1 i X i 2F48X/4 for inverse zoneVo u Vso F48X/5 1 i X i 2remote reading, remote setting* (3)function code F48identification number 148hparameters Iso set point unit : 0.1 x A(order of parameters) tripping sector unit: index (4)Vso set pointT time delaymemory timeunit: Vunit: 10 x msunit: 10 x ms(1)in reference conditions (IEC 60255-6).(2)Ino = In if the sum of the three phase currents is used for the measurement.Ino = sensor rating if the measurement is taken by a CSH core balance CT.Ino = In of the CT is the measurement is taken by a 1 A or 5 A current transformer.Ino = core balance CT rating if the measurement is taken by a core balance CT other than CSH.(3)the data formats are defined in the manuals which describe each communication protocol.(4)meaning of tripping index: 0: ±83° angle 2: ±86° angle.Protection functions2/17